JPS63137387A - Ic card memory - Google Patents

Abstract

PURPOSE:To provide the titled IC card memory with a rewriting preventing function by sealing a rewriting preventing circuit integrally with a substrate. CONSTITUTION:Plural semiconductor memory devices 4 and the rewriting preventing circuit 5 for preventing rewriting in these devices 4 are integrally sealed in the substrate. The circuit 5 is constituted by separating and cutting a part of the substrate and opening a part of the circuit. When a specific substrate part 2 out of the substrate 1 is separated and cut off at the time of ending writing in a device 4, a conductor 6 integral with the substrate 2 is cut out and paired terminals A, B are released.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC memory card incorporating a semiconductor storage device capable of preventing rewriting.

[Prior Art] Conventionally, in this type of IC memory card, a mechanical switch connected to a switching circuit is attached to a part of the board in order to prevent rewriting to the semiconductor storage device enclosed within the board. Ta.

[Problems to be Solved by the Invention] Incidentally, in recent years, there has been a tendency for IC memory cards to be made thinner, and if the thickness is less than 1#1I11, it is extremely difficult to provide a mechanical switch as described above.

The object of the present invention is to
1n! To provide an IC memory card having a board of 14 or less and a function of preventing rewriting.

[Differences between the invention and the prior art] In contrast to the above-described conventional mechanical switch, the present invention has an original content in that rewriting is prevented by cutting a part of the board.

[Means for Solving the Problems] The present invention provides an IC memory card in which a plurality of semiconductor storage devices are encapsulated, in which a portion of the circuit is opened as part of the substrate is separated and cut, and the circuit is disconnected to the semiconductor storage device. This IC memory card is characterized in that a rewrite prevention circuit that prevents rewriting is integrally enclosed within a substrate.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a plurality of semiconductor memory devices 4 and a rewrite prevention circuit 5 for preventing rewriting to the semiconductor memory devices 4 are integrally enclosed within a substrate 1. As shown in FIG. The relationship between the semiconductor memory device 4 and the rewrite prevention circuit 5 is shown in FIG. That is, in FIG. 2, the rewrite prevention circuit 5
type MOS transistor Q1 and N type MOS transistor Q2.

Q3, P-type MOS transistor Q1 and N-type MO
At which connection point N2 of the S transistor Q2 is the semiconductor memory device 4 connected?
While connecting the write/read terminal R/W of
The gate of an N-type MOS transistor Q3 is connected to the connection point N2, and the transistors Q1. The drain of the transistor Q3 is connected to the connection point N1 of the gate of the transistor Q2. Furthermore, a pair of open terminals A and B are formed midway between the train of the N-type MOS transistor Q3 and the power source, and electrical continuity is established between the pair of open terminals A and B through a cuttable conductor 6.

As shown in FIG. 1, this conductor 6 is attached to the substrate 2 at a specific position to be separated and cut. Reference numeral 3 denotes an external connection terminal for transmitting and receiving signals, supplying power, etc. between the semiconductor storage device 4 and the rewrite prevention circuit 5 and external equipment.

In the embodiment, when the substrate 2 at a specific position of the substrate 1 is separated and cut when writing to the semiconductor memory device 4 is completed, the conductor 6 integrated with the substrate 2 is cut out, and the pair of terminals A and B are separated. It will be released.

When the terminals A and B are opened, the contact N1, which was kept at the power supply potential, gradually drops and the P-type transistors Q1 and N
The inverter circuit constituted by the type transistor Q2 is turned off, and the level of the contact N2 changes from HIGH to LOW. Since the write/read terminal R/W of the semiconductor storage device 4 is connected to the above contact N2, signal input to the terminal R/W is blocked, rewriting is impossible, and the memory contents of the IC memory card are is retained.

In the previous embodiment, the substrate 2 at a specific position along the edge of the substrate 1
Although, as shown in FIG. 3, the substrate 2 at a specific position inside the edge of the substrate 1 may be separated and cut.

In this case, since the substrate 2 is not exposed at the edge, there is no possibility of objects getting caught on the cut portion.

[Effects of the Invention] As explained above, according to the present invention, an electric switch is used that prevents rewriting to a semiconductor memory device by opening a part of the circuit, so that general-purpose thin film technology can be used. can be encapsulated in a thin substrate, and the thin I
This has the effect of imparting a rewrite prevention function to the C memory card.

[Brief explanation of the drawing]

FIG. 1 is an external view of an IC memory card showing one embodiment of the present invention, FIG. 2 is a diagram showing an example of a circuit showing the rewrite prevention mechanism of the present invention, and FIG. 3 is another embodiment of the present invention. FIG.

Claims (1)

[Claims] (1) IC with multiple semiconductor memory devices encapsulated within the substrate
In memory cards, due to the separation and cutting of a part of the board,
An IC memory card characterized in that a rewrite prevention circuit that prevents rewriting to the semiconductor storage device when a part of the circuit is opened is integrally enclosed within a substrate.