JPH0474699A - Ic card - Google Patents

Abstract

PURPOSE:To indicate a warning of an abnormal temperature increase by a method wherein a liquid crystal material changing its color in accordance with a temperature change is applied to the surface of an IC card incorporating a semiconductor element and other circuit elements. CONSTITUTION:An inner temperature of an IC card is increased by a heat generation of a semiconductor element incorporated in the IC card caused by a power loss. Furthermore, the surface temperature of a metallic panel 4 is also increased. A liquid crystal material 7 changing its color in accordance with the temperature of the metallic panel 4 when the inner temperature of the IC card reaches a rating temperature of the semiconductor inside the card is applied to the surface of the metallic panel 4. In this manner, a warning of an abnormal temperature change of the surface of the IC card can be indicated by a color change of the liquid crystal material 7. A warning against an abnormal ambient temperature increase outside the IC card caused by other factors can be similarly indicated, and a malfunction of the system can be prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a temperature change/increase display on one surface of an IC card incorporating a semiconductor element.

[Conventional technology]

FIG. 3 is a perspective view of a conventional IC card, and FIG. 4 is a sectional view taken along line AA shown in FIG.

In the figure, (1) is the semiconductor element, (2) is the wiring board % on which the semiconductor element (1) is mounted (31 is the wiring board (2)
The resin molded frame % (4) that fixes the resin molded frame (3) and the surface of the pad of the semiconductor element (1),
A metal panel is fixed with an adhesive (5), and a connector (6) is used to establish an electrical connection between the industrial C card and an external device.

Next, the operation will be explained. Power of semiconductor element (1) 1
The heat generated from the center is radiated to the outside of the IC card.
, j, There are mainly the following two routes. 01 is from the semi-1 netchip to the surface of the package of the semiconductor device (1), and then to the adhesive (5) that connects the semiconductor device (1) and the metal panel (4). The other route is to dissipate from the surface of the metal panel (4) to the outside atmosphere through the lead of the semiconductor element (1) and the algae hacoon of the wiring board (2). This is the route through which the air inside the card is dissipated from the surface of the metal panel (4) to the outside atmosphere.

[Problem to be solved by the invention]

Since the conventional work 0 card is structured as shown above,
The amount of power loss in internal semiconductor elements or IC
Depending on the ambient temperature of the card, the internal temperature of the IC card may
There were problems such as exceeding the rated temperature of the semiconductor elements and mechanical parts inside the IC card.

This invention was made in order to solve the above-mentioned problems, and the purpose is to obtain an IC card that can detect the surface temperature of the IC card and display a warning when the temperature has increased abnormally. do.

[Means to solve the problem]

The IC card according to the present invention has a liquid crystal material coated on the surface of the IC card, which changes color upon temperature change.

[For production]

The IC card according to the present invention detects that the Table I temperature of the IC card has exceeded a specified temperature.

To display a warning about temperature rise rather than changing the color of a part or the entire surface of an IC card.

[Harvest example]

Hereinafter, an example of the present invention will be explained with reference to the drawings. Figure 2 is a perspective view of the construction C card, Figure 2 is the B- card shown in Figure 1.
FIG. In the figure, (1), +
2), (31, (41, (5), and (6)) are the same as those shown in the conventional example shown in FIG. 2, so their explanation will be omitted.

(7): is a liquid crystal material thinly applied to a part of the surface of the metal panel (4).

Next, the operation will be explained. Due to heat generation due to power loss in the semiconductor element (1) inside the IC card, the temperature inside the IC card rises, and the surface temperature of the metal panel (4) also rises. By applying a liquid crystal material (7) that changes color at the temperature of the metal panel (4) at the time when the IC card internal temperature reaches the rated temperature of the internal semiconductor element (1) to the surface of the metal panel (4), The liquid crystal material (7) changes color and can display a warning about an abnormality on the surface of the engineering C card.

2. In the above example, the case where the liquid crystal material (7) that changes color according to temperature changes is applied to a part of the surface of the metal panel (4) was explained. It may also be applied, and in this case, if the same effect as in the above embodiment can be obtained, it will also be useful for detecting abnormal heat generation locations within the IC card when opened.

In addition, in the above actual example, we have explained the temperature rise inside the mechanical C card due to heat generation due to power loss of the semiconductor element (1) inside the IC card when the IC card is operating, or the temperature rise inside the mechanical C card due to other factors. A similar warning display can also be displayed for an abnormal rise in temperature.

〔Effect of the invention〕

As described above, according to the present invention, by coating the surface of an IC card with a liquid crystal material that changes color depending on temperature changes,
Detects the temperature on the surface of the engineering C card and displays a warning if an abnormal temperature rise occurs.

This has the effect of preventing system malfunctions.

[Brief explanation of the drawing]

Figure 2 is a sectional view at B@B shown in Figure 1, Figure 3 is a perspective view of a conventional IC card, Figure 4 is a perspective view of an IC card according to an embodiment of the invention. It is a sectional view at A@A shown in Summer 3. In the figure, (1) is a semiconductor element, (2) is a wiring board, and (3)
(4) is a metal panel, (5) is an adhesive.・Ra) is a connector, and (7) is a liquid crystal material. In addition, the same reference numerals in the figures indicate the same or equivalent parts. 0 Figure 1 Figure 2

Claims (1)

[Claims] 1. An IC card containing a semiconductor element and other circuit elements, characterized in that the surface of the IC card is coated with a liquid crystal material that changes color according to temperature changes.