IC Card

Abstract: A first invention relates to an IC card (1) provided with a card base (3) having the front and back sides; electromagnetic stripes (7) arranged on the back side of the substrate, and capable of storing information; and a module (5) incorporating a semi-conductor circuit device having connecting terminals (5-1) arranged on a given area on the front side of the base (3) so as to connect the card (1) with external equipement, wherein the end (5a) of the module (5) is arranged in the direction perpendicular to the electromagnetic stripes (7). With the structure described above, it is possible to reduce the step on the base (3) in the vicinity of the upper part of the module (5), thus relaxing the stress exerted on this part. Further, according to a second invention, the card (1) has a structure such that the end (5b) gradually becomes thinner. The step in the vicinity of the upper part of the module (5) is further smaller, so that the stress exerted on the part is relaxed. Furthermore, according to a third invention, a part of the end (5b) has a cuspidated shape, and the module (5) is so shaped that the leading end (5c) of the end (5b) is cuspidal. Hence, the step in the vicinity of the upper part of the base (3) is smaller, thus enabling the stress exerted on the part to be relaxed. The invention provides an IC card having a high durability.

Description: The present invention relates to an IC card with a built-in semiconductor integrated circuit device, particularly to a structure of an IC card having a front surface on which ready access terminals are provided for connecting to an external device and a reverse surface on which a magnetic body line (magnetic stripe) is provided for storing information therein. An IC card comprises a central processing unit (CPU) and a memory circuit which are respectively built in a card. That is, the IC card is a kind of computer. Accordingly, the IC card can be applied to a variety of purposes. To make the IC card generalize, the standardization of the IC card is now under progress internationally according to a standard of an International Organization for Standardization (hereinafter referred to as an ISO) and in Japan according to a standard of a Japanese Industrial Standard (hereinafter referred to as a JIS). For example, according to ISO7816-1, ISO7816-2 (corresponding to JISX6303) a distance A ranging from an upper end 101 of an IC card 100 to an upper side of ready access terminals 103-1, 103-2 (a side nearest to the upper end 101 among sides defining terminals) of an IC chip module 103 is set to be 19.23mm in maximum as illustrated in Figure 11. According to an ISO7811-5 (corresponding to JISX6302) a distance B ranging from the upper end 101 of the IC card 100 to a base of a third track 105a of a magnetic stripe 105 is prescribed to be 15.32mm at minimum and 15.82mm at maximum as illustrated in Figure 12. Figure 13 is an enlarged cross-sectional view of a main portion of the IC card provided with a magnetic stripe which meets the standard as set forth above (which is so-called JIS-I type IC card in Japan). A positional relation between the IC chip module 103 and the magnetic stripe 105 can be easily understood from Figure 13. In this case, a distance C ranging from the upper end 101 of the IC card to a base of the magnetic stripe 105 comes to 16.82mm which is the sum of the distance B ranging from the upper end 101 to the base of the third track 105a, i.e. 15.82mm in maximum and a 1mm margin for covering errors. Since the distance A ranging from the upper end 101 to the upper sides of the ready access terminals 103-1, 103-2 is 19.23mm in maximum, a distance D ranging from the upper end 101 to the upper side of the IC chip module 103 comes to 18.23mm which is the difference between the distance A and a 1mm margin to be involved in manufacturing the module. Accordingly, a gap E (-D-C), i.e. between the base of the magnetic stripe 105 and the upper side of the IC chip module 103 comes to 1.41mm. If stress is applied to the IC card to bend the IC card in a direction of a short side thereof as illustrated in Figure 14 the stress is concentrated to the portion adjacent to the gap E, particularly to the portion adjacent to the upper side of the IC chip module 103 since deformation in thickness of the card substrate is sharp at the portion adjacent to the gap E. The present invention concerns an IC card of the kind comprising a card substrate having a front and a back surface, a magnetic stripe arranged on the back surface of the card substrate for storing information, a module arranged on the front surface of the card substrate including a semiconductor integrated circuit device having connecting terminals for connecting to an external device. Such an IC card is known from GB-A-2081644. A problem with this type of IC card is that a high stress concentration can occur in the portion of the card surrounding the module which can result in the module detaching itself from the card base or cause the IC chip inside the module to be destroyed. It is an object of the invention to provide an IC card capable of relaxing stress and enhancing durability compared with the prior art IC card. According to an aspect of the invention there is provided a module which gradually reduces in thickness towards at least one edge. Preferably, the or each edge is pointed in shape to form a tip. In one embodiment, the module is pentagonal or hexagonal in shape. Preferably, the module on the front surface of the card partially overlaps the magnetic stripe on the back surface of the card. The preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of an IC card according to a first embodiment of the present invention; Figure 2 is a plan view of an IC chip module according to the first embodiment; Figure 3 is a cross-sectional view of the IC chip module of Figure 2; Figure 4 is a cross-sectional view of a main portion of the IC card for explaining the positional relation between the IC chip module and a magnetic stripe according to the first embodiment; Figure 5 is an enlarged cross-sectional view for explaining in detail the cross-sectional view of the main portion of Figure 4; Figure 6 is a plan view of an IC card according to a second embodiment of the present invention; Figure 7 is a plan view of an IC chip module according to the second embodiment; Figure 8 is a cross-sectional view of the IC chip module of Figure 7; Figure 9 is a cross-sectional view of a main portion of the IC card for explaining the positional relation between the IC chip module and a magnetic stripe according to the second embodiment; Figure 10 is an enlarged cross-sectional view for explaining in detail the cross-sectional view of the main portion of Figure 9; Figure 11 is a plan view showing an external appearance of a front surface of a general IC card; Figure 12 is a plan view showing an external appearance of a reverse surface of the IC card of Figure 11; Figure 13 is a cross-sectional view of a main portion of the IC card of Figure 11; and Figure 14 is a cross-sectional view for explaining the state where stress is applied to the IC card of Figure 11. A first embodiment of the present invention will be described with reference to Figures 1-5. An IC card 1 which is the same as a general IC card in that it comprises an IC chip module 5 (hereinafter referred to as a module) which is provided on the front surface of an IC card substrate 3 and includes a semiconductor circuit device therein provided with a plurality of read access terminals for connecting to an external device and a magnetic stripe 7 which is provided on a reverse surface of the card substrate 3 for storing information therein. The module 5 comprises a substrate, a semiconductor circuit device mounted on one surface of the substrate, a mold resin for covering the substrate and the semiconductor circuit device and ready access terminals provided on the other surface of the substrate so as to connect to an external device (not shown). The module is generally accommodated in a module accommodation portion which is a so-called spot facing defined on the front surface of the card substrate and its neighbouring portion. Likewise, the magnetic stripe 7 is also accommodated in the so-called spot facing defined on the reverse surface of the card substrate and its neighbouring portion. As shown in Figure 1 the IC card has a point-shaped portion 5b which is formed as illustrated in Figure 2 at the end portion 5a of the module 5 of the IC card in the first embodiment and the thickness of the end portion 5b is gradually thinned toward a tip end 5c as illustrated in Figure 3. As is easily understood from Figures 2 and 3, the module is pentagonal in plane and the thickness of the module 5 is gradually thinned from a base 5d of the end portion 5b toward the tip end 5c. That is, the end portion 5b has a tapered portion 5e. It is a matter of course that in this IC card, a distance N ranging from the upper end 3a of the IC card substrate 3 to the upper end, i.e. tip end 5c of the module 5 is formed to be less than a distance M ranging from the upper end 3a to a base 7a of the magnetic stripe 7. A cross-sectional view of the main portion taken along Y-Y' of Figure 1 is illustrated in Figure 4 so that the positional relation between the module 5 and the magnetic stripe 7 is easily understood. As illustrated in Figure 4, the IC card of the present embodiment has the module 5 end portion of which is positioned to extend to the upper portion of the magnetic stripe 7 and the thickness of the end portion is gradually thinned. A portion which enlarges and describes the module 5 in detail is illustrated in Figure 5. As is evident from Figure 5 the end portion 5b of the module 5 is formed to be gradually thinned in its thickness toward the tip end 5c thereof. According to the first embodiment as described above, since deformation in thickness of the card substrate is gentle at the portion adjacent to the gap between the module and the magnetic stripe than the stress to be applied to this portion is more relaxed. A second embodiment of the present invention will be described with reference to Figures 6-10. In this embodiment components which are the same as those explained in the first embodiment are denoted at the same numerals and explanation thereof is omitted. Figure 6 is a plan view of an IC card typically illustrating the present embodiment. The IC card in this embodiment further includes an end portion 5f at the portion opposite to the end portion 5b of the module 5 in the first embodiment. In the first embodiment there is considered the "gap" portion alone where the stress for bending the IC card in the direction of the short sides thereof is most concentrated. According to this embodiment, there is considered a lower portion of the module 5 where such a stress is secondly concentrated so as to obtain the IC card having enhanced durability. The end portion 5f has the same shape as the end portion 5b. That is, the end portion 5f is formed symmetrically in its shape with the end portion 5b as illustrated in Figure 7. Further, the end portion 5f is gradually thinned in its thickness toward a tip end 5g thereof as illustrated in Figure 8. As is easily understood from Figures 7 and 8, the module 5 is hexagonal in plane and the thickness of the end portion 5f is gradually thinned in its thickness from the base 5h thereof toward the tip end 5g. That is the end portion 5f has a tapered portion 5i. It is a matter of course that in this IC card, the distance N ranging from the upper end 3a of the card substrate 3 to the upper end, i.e. tip end 5c of the module 5 is formed to be less than the distance M ranging from the upper end 3a to the base 7a of the magnetic stripe 7. A cross-sectional view of the main portion taken along Z-Z' of Figure 6 is illustrated in Figure 9 so that the positional relation between the module 5 and the magnetic stripe 7 is easily understood. In the IC card of the present embodiment as illustrated in Figure 9 the end portion of the module 5 is positioned to extend to the upper portion of the magnetic stripe 7 and the thickness thereof is gradually thinned and an end portion opposite to this end portion is formed symmetrically in its shape with this end portion. A portion which enlarges and explains the module 5 in detail is illustrated in Figure 10. As is evident from Figure 10 the end portion 5f of the module 5 is formed to be gradually thinned in its thickness toward the tip end 5g like the end portion 5b. According to the aforementioned second embodiment, since deformation in thickness of the card substrate is gentle at the portion adjacent to the gap between the module and the magnetic stripe, the stress to be applied to this portion is relaxed, and further the stress is likewise relaxed at the portion where the stress is secondly concentrated. According to the present invention as explained above, even if the stress for bending the IC card in the direction of short sides thereof is applied to the IC card, the stress can be relaxed, which leads to the provision of the IC card having high durability. The present invention can be applied to an IC card with a built-in semiconductor integrated circuit device, particularly to an IC card including ready access terminals provided on the front surface thereof for connecting to an external device and a magnetic body line (magnetic stripe) provided on the reverse surface thereof for storing information therein. According to a first aspect of the preferred embodiment since the module is structured in that the thickness of the end portion thereof is gradually thinned, deformation in thickness of the card substrate is further reduced at the portion adjacent to the upper portion of the module so that the stress to be applied thereto is more relaxed. Furthermore, according to a second aspect of the preferred embodiment since the module is structured in that a part of the end portion thereof has a point-shaped portion, more in detail, the module is formed pentagonal or hexagonal and it is disposed in the manner that the tip end of the end portion is point-shaped, deformation in thickness of the card substrate is reduced at the portion adjacent to the upper portion of the module so that the stress to be applied thereto is relaxed. If the first and second embodiments of the present invention are applied to the lower portion of the module, in addition to the upper portion of the module of the IC card, the stress can be relaxed at the portion where it is most concentratedly applied in the direction of the short sides of the IC card and at the portion where it is secondly concentratedly applied to the lower portion of the module 5. As a result, it is possible to provide an IC card having high durability.

Claims: An IC card comprising a card substrate (3) having a front and a back surface, a magnetic stripe (7) arranged on the back surface of the card substrate for storing information, a module (5) arranged on the front surface of the card substrate (3) including a semiconductor integrated circuit device (5-3) having connecting terminals (5-1) for connecting to an external device characterised in that the module (5) gradually reduces in thickness towards at least one edge (5a). An IC card according to claim 1, wherein the or each edge (5a) is pointed in shape to form a tip (5c). An IC card according to claim 2 wherein the module (5) is pentagonal or hexagonal in shape. An IC card according to any preceding claim wherein the module (5) on the front surface of the card partially overlaps the magnetic stripe (7) on the back surface of the card. An IC card according to any preceding claim wherein the module comprises a substrate (5-2) and a semiconductor integrated circuit device (5-3) mounted on one side of the substrate (5-2). An IC card according to any preceding claim wherein the magnetic stripe (7) and module (5) are each located in a spot facing on each side of the card substrate (3).

Inventors: ATSUMI SHIRO, ATSUMI, SHIRO, ATSUMI, SHIRO, OKI ELECTRIC INDUSTRY CO.,LTD.
Applicants: OKI ELECTRIC IND CO LTD, OKI ELECTRIC INDUSTRY COMPANY, LIMITED
Application year: 1993
Main classification: B42D15
IPC codes: G06K19