Device incorporating self-destructive element, manufacturing method for device incorporating self-destructive element, and design method for self-destructive element

Abstract

To provide a device incorporated with a self-destruction element which enables an autonomous security measure of hardware.SOLUTION: A device 1 is incorporated with a self-destruction element 4, in which the self-destruction element 4 includes a movable electrode part 41, the movable electrode part 41 is designed using an S-N curve so as be self-destructed when a predetermined number of times of predetermined vibration are applied thereto, and the S-N curve indicates a relation between the number of times of vibration and vibration strength determined by performing a fatigue fracture characteristic test on the self-destruction element 4. The self-destruction element 4 is provided between a power source V and a ground G supplied to a semiconductor integrated circuit 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a device incorporating a self-destructing element and Manufacturing method of device incorporating self-destructive element and This relates to a method for designing a self-destructing element. [Background technology]

[0002] In recent years, the number of devices that can connect to the Internet and receive various services has begun to increase. Such devices are called IoT (Internet of Things) devices.

[0003] Incidentally, security measures for such IoT devices are implemented on the software side (see, for example, Patent Document 1). The invention described in Patent Document 1 creates action plan information in advance, and if the location information of the device to be monitored does not match this action plan information, the device is locked, thereby making it impossible for unauthorized users to use the device even after the password has been leaked. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-220017 Summary of the Invention [Problem to be solved by the invention]

[0005] However, implementing security measures for IoT devices on the software side raises the risk of software tampering, and there are vulnerabilities such as the possibility of sending commands to IoT devices by mistake, such as self-destructing commands using software.

[0006] Furthermore, as the number of IoT devices continues to increase and spreads in large numbers (for example, trillions of devices) throughout the environment, if IoT devices that have outlived their usefulness continue to operate, wireless radio waves will continue to be emitted in various locations.Since radio wave resources are limited, there is a problem that unless IoT devices self-destruct after a certain amount of use, the available bandwidth will quickly become congested.

[0007] In light of these problems, there has been a growing demand in recent years for autonomous hardware security measures that do not require software instructions, in order to avoid software tampering and to realize maintenance-free and recovery-free systems.

[0008] In view of the above, an object of the present invention is to provide a device incorporating a self-destructive element capable of implementing autonomous hardware security measures, and a method for designing such a self-destructive element. [Means for solving the problem]

[0009] The above object of the present invention can be achieved by the following means: Note that the parentheses indicate reference symbols of embodiments to be described later, but the present invention is not limited to these.

[0010] A device incorporating the self-destructing element according to claim 1. Manufacturing method is a device (1) incorporating a self-destructing element (4) Manufacturing method And, The self-destructing element (4) includes a movable elastic body (movable electrode portion 41), The elastic body (movable electrode portion 41) is It is designed using an S-N curve to self-destruct when a certain number of vibrations are applied. The SN curve is characterized in that it shows the relationship between the number of vibrations and the vibration intensity obtained by carrying out a fatigue fracture characteristic test on the self-destructive element (4) (see FIG. 2).

[0011] Also, a device incorporating the self-destructing element according to claim 2. Manufacturing methodA device (1) incorporating the self-destructing element (4) according to claim 1. Manufacturing method The self-destruction element (4) is provided between a power supply (V) supplied to the semiconductor integrated circuit (3) and a ground (G).

[0014] On the other hand, the design method of the self-destructive element according to claim 3 is to design a self-destructive element (4) having a movable elastic body (movable electrode portion 41), A fatigue fracture characteristic test is conducted on the self-destructive element (4) to create an SN curve showing the relationship between the number of vibrations and the vibration intensity, and then the SN curve is used to design the elastic body (movable electrode part 41) to self-destruct when a predetermined number of vibrations are applied. On the other hand, a device incorporating a self-destructive element according to claim 4 comprises a semiconductor integrated circuit (3) having elements such as a capacitance element and a resistance element, formed on the semiconductor integrated circuit (3) so as to be provided between a power supply (V) supplied to the semiconductor integrated circuit (3) and a ground (G); The semiconductor integrated circuit (3) The aforementioned Power supply (V) It plays a role in passing the signal through so that it is electrically connected to the ground (G). A self-destructing element (4) of a MEMS structure, The self-destructing element (4) is a fixed electrode portion (40) fixed on the semiconductor integrated circuit (3); a movable electrode portion (41) provided at a distance from the fixed electrode portion (40) and vibrating at least in response to environmental vibrations; The movable electrode portion (41) breaks at a predetermined number of vibrations according to the selected shape and material of the movable electrode portion (41), the vibration acceleration of the semiconductor integrated circuit (3), and the vibration intensity based on the mass of the movable electrode portion (41). death, When the movable electrode portion (41) breaks, the electrical connection between the power supply (V) and the ground (G) for the semiconductor integrated circuit (3) is cut off. It is characterized by the following. [Effects of the Invention]

[0015] Next, the effects of the present invention will be described with reference to the drawings. Note that the reference symbols in parentheses are those of the embodiments described below, but the present invention is not limited to these.

[0016] Claim 1,3,4 According to the invention, even without using software, when a predetermined number of vibrations are applied to the self-destructing element (4), the movable electrode part (41) self-destructs. Set in This makes it impossible to tamper with the hardware (such as by issuing a command to disable destruction), thereby enabling autonomous hardware security measures.

[0017] Furthermore, according to the invention of claim 2, the self-destructive element (4) is provided between the power supply (V) and ground (G) supplied to the semiconductor integrated circuit (3), so that the semiconductor integrated circuit (3) can be reliably disabled from functioning, and thus the device (1) incorporating the self-destructive element can be reliably rendered physically unusable. [Brief explanation of the drawings]

[0020] [Figure 1] (a) is a longitudinal cross-sectional view of a device incorporating a self-destructive element according to one embodiment of the present invention; (b) is a longitudinal cross-sectional view illustrating the breakage (self-destruction) of the movable electrode part of the device incorporating a self-destructive element according to the same embodiment; and (c) is a block diagram illustrating the location where the self-destructive element according to the same embodiment is located. [Figure 2] 10 is a diagram showing an SN curve showing the relationship between the number of vibrations and the vibration intensity obtained by performing a fatigue fracture characteristic test on the self-destructive element according to the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] A device incorporating a self-destructive element according to the present invention and a method for designing a self-destructive element will be specifically described below with reference to the drawings. In the following description, when referring to directions such as up, down, left, and right, they refer to the directions when viewed from the front of the illustration.

[0022] As shown in Fig. 1, a device 1 incorporating a self-destructive element according to this embodiment is as shown in Fig. 1(a). To explain in more detail, the device 1 incorporating a self-destructive element is mainly composed of a substrate 2, a semiconductor integrated circuit 3, and a self-destructive element 4. The substrate 2 is formed in a rectangular shape as shown in Fig. 1(a), and is formed from, for example, a silicon substrate.

[0023] On the other hand, as shown in FIG. 1(a), the semiconductor integrated circuit 3 is formed on the substrate 2 and has various elements such as capacitance elements, resistance elements, and memory cells.

[0024] As shown in Fig. 1(a), the self-destructive element 4 is formed on the semiconductor integrated circuit 3, and is formed of a MEMS structure, which is a microstructure formed by microfabrication using semiconductor manufacturing technology. As shown in Fig. 1(a), the self-destructive element 4 formed of the MEMS structure in this way is composed of a fixed electrode part 40 fixed on the semiconductor integrated circuit 3, and a movable electrode part 41 provided at an interval from the fixed electrode part 40, and the movable electrode part 41 is movable by being elastically supported by a support part 42.

[0025] The self-destructive element 4 configured as described above is designed so that the movable electrode portion 41 of the self-destructive element 4 breaks (self-destructs) when a predetermined number of vibrations are applied in the direction of arrow Y, as shown in FIG. 1(b). To explain this in more detail, the self-destructive element 4 is designed using the S-N curve shown in FIG. 2. That is, the S-N curve shown in FIG. 2 shows the relationship between the number of vibrations and the vibration intensity obtained by conducting a fatigue fracture characteristic test on the self-destructive element 4. The S-N curve indicates that the vibration intensity increases toward the left side of the curve, and the movable electrode portion 41 breaks after a small number of vibrations, i.e., the movable electrode portion 41 self-destructs after a short lifespan. On the other hand, the S-N curve indicates that the vibration intensity decreases toward the right side of the curve, and the movable electrode portion 41 breaks after a large number of vibrations, i.e., the movable electrode portion 41 self-destructs after a long lifespan. Therefore, by using such an SN curve, it is possible to design the movable electrode portion 41 so that it breaks (self-destructs) when a predetermined number of vibrations are applied in the direction of the arrow Y, as shown in Figure 1(b). More specifically, when forming the self-destructive element 4 on the semiconductor integrated circuit 3, the vibration intensity can be calculated from the acceleration of the vibration of the semiconductor integrated circuit 3 and the mass of the movable electrode portion 41. Therefore, if the vibration intensity can be calculated, it is possible to use the SN curve shown in Figure 2 to design how many vibrations must be applied to the movable electrode portion 41 to cause it to break (self-destruct).

[0026] Vibrations caused by the environment surrounding the semiconductor integrated circuit 3, etc., as described above, are called environmental vibrations, and correspond to region R2 shown in FIG. 2. Region R1 shown in FIG. 2, on the other hand, is called forced vibrations, such as vibrations caused by electrostatic attraction. Such vibrations caused by electrostatic attraction can be artificially generated by applying a voltage to the self-destructive element 4, which generates a periodic electrostatic attraction on the movable electrode portion 41. This periodically applies vibrations caused by electrostatic attraction to the movable electrode portion 41, causing the movable electrode portion 41 to break (self-destruct). This makes it possible to simply and easily forcefully break (self-destruct) the movable electrode portion 41.

[0027] To create an SN curve such as that shown in FIG. 2 , first, the material and shape of the self-destructive element 4 are selected and manufactured. Then, an experiment is conducted to determine how many vibrations are required to break (self-destruct) the movable electrode portion 41 when the manufactured self-destructive element 4 is artificially subjected to vibrations at a certain intensity. Next, the same self-destructive element 4 is artificially subjected to vibrations at different intensities, and an experiment is conducted to determine how many vibrations are required to break (self-destruct) the movable electrode portion 41. By repeatedly changing the intensity and conducting the experiment to determine how many vibrations are required to break (self-destruct) the movable electrode portion 41, it is possible to plot (draw) the number of vibrations versus the vibration intensity at which the movable electrode portion 41 breaks (self-destructs), thereby creating an SN curve such as that shown in FIG. 2 . It is known that the SN curve varies depending on the selected material and shape. Therefore, taking this into consideration, when designing the self-destructive element 4, it is preferable to design it based on the selected material and shape during the experiment.

[0028] Thus, the self-destructive element 4 designed in this way does not have the sensor function that MEMS structures inherently have, and normally does not play any role but simply passes signals through. Specifically, as shown in Figure 1(c), the self-destructive element 4 is formed on the semiconductor integrated circuit 3 so as to be provided between the power supply V supplied to the semiconductor integrated circuit 3 and the ground G (see Figure 1(a)).

[0029] In this way, in the device 1 incorporating the self-destructive element, the self-destructive element 4 simply passes signals through, and the semiconductor integrated circuit 3 is electrically connected to the power supply V and ground G as shown in FIG. 1(c). Therefore, the semiconductor integrated circuit 3 performs its intended function without any problems. In this state, as shown in FIG. 1(b), if a predetermined number of vibrations are applied in the direction of arrow Y, and the movable electrode portion 41 of the self-destructive element 4 breaks (self-destructs), the self-destructive element 4 can no longer pass signals through. Therefore, the electrical connection between the semiconductor integrated circuit 3 and the power supply V and ground G as shown in FIG. 1(c) is severed, and the semiconductor integrated circuit 3 can no longer function, and the device 1 incorporating the self-destructive element becomes physically unusable.

[0030] According to the present embodiment described above, the movable electrode portion 41 of the self-destructive element 4 is designed to break (self-destruct) when a predetermined number of vibrations are applied to the self-destructive element 4 without using software, making it impossible to tamper with it by software (such as executing a command to cancel destruction), thereby enabling autonomous hardware security measures. This solves the problem of vulnerability caused by software security measures, and also solves the problem of limited wireless radio wave bandwidth usage.

[0031] Furthermore, according to this embodiment, such a self-destructive element 4 is provided between the power supply V supplied to the semiconductor integrated circuit 3 and the ground G, so that the semiconductor integrated circuit 3 can be reliably prevented from performing its functions, and thus the device 1 incorporating the self-destructive element can be reliably rendered physically unusable.

[0032] Furthermore, according to this embodiment, the self-destructive element 4 is formed of a MEMS structure that does not have a sensor function, and therefore the self-destructive element 4 itself does not normally play any role, making it possible to place the self-destructive element 4 in any location.

[0033] However, the self-destructive element 4 can also be formed of a MEMS structure having a sensor function. In this way, if the movable electrode part 41 of the self-destructive element 4 breaks (self-destructs), the sensor function will no longer function, and thus the device 1 incorporating the self-destructive element can be physically rendered unusable.

[0034] It should be noted that the shapes and the like shown in this embodiment are merely examples, and various modifications and changes are possible within the scope of the gist of the present invention as set forth in the claims. For example, in this embodiment, a MEMS structure has been described as an example of the self-destructive element 4, but the self-destructive element 4 is not limited to this, and any element having a movable elastic body, such as the movable electrode portion 41, may be used.

[0035] Furthermore, in this embodiment, the self-destructive element 4 is formed on the semiconductor integrated circuit 3, but this is not limiting, and the semiconductor integrated circuit 3 and the self-destructive element 4 may be electrically connected by wire bonding or the like.

[0036] The device 1 incorporating the self-destructive element of this embodiment can be applied to various devices such as physical sensors, chemical sensors, microactuators, and vibration power generation elements. [Explanation of symbols]

[0037] 1. Devices incorporating self-destructing elements 3. Semiconductor Integrated Circuits 4 Self-destructing element 41 Movable electrode part (movable elastic body) V power supply G Ground

Claims

1. A method for manufacturing a device incorporating a self-destructive element, comprising: The self-destructing element is A fixed electrode portion; The electrode assembly is formed of a MEMS structure having a movable electrode portion provided at an interval from the fixed electrode portion, The movable electrode portion is It is designed using an S-N curve to self-destruct when a certain number of vibrations are applied. The SN curve indicates the relationship between the number of vibrations and the vibration intensity obtained by carrying out a fatigue fracture characteristic test on the self-destructive element. A method for manufacturing a device incorporating a self-destructive element.

2. 2. The method for manufacturing a device incorporating a self-destructive element according to claim 1, wherein the self-destructive element is provided between a power supply supplied to a semiconductor integrated circuit and ground.

3. A fixed electrode portion; When designing a self-destructive element formed of a MEMS structure having a movable electrode portion provided at an interval from the fixed electrode portion, A method for designing a self-destructive element in which a fatigue fracture characteristic test is conducted on the self-destructive element to create an SN curve showing the relationship between the number of vibrations and the vibration intensity, and then the SN curve is used to design the movable electrode part so that it self-destructs when a predetermined number of vibrations are applied.

4. a semiconductor integrated circuit having elements such as a capacitance element and a resistance element; a self-destructive element of a MEMS structure that is formed on the semiconductor integrated circuit so as to be provided between a power supply supplied to the semiconductor integrated circuit and a ground, and that serves to pass a signal so that the semiconductor integrated circuit, the power supply, and the ground are electrically connected; The self-destructing element is a fixed electrode portion fixed on the semiconductor integrated circuit; a movable electrode portion provided at an interval from the fixed electrode portion and vibrating at least in response to environmental vibrations; the movable electrode portion breaks after a predetermined number of vibrations corresponding to the selected shape and material of the movable electrode portion, as well as the vibration intensity based on the acceleration of the vibration of the semiconductor integrated circuit and the mass of the movable electrode portion; A device incorporating a self-destructing element that, when the movable electrode portion breaks, cuts off the electrical connection between the power supply and the ground for the semiconductor integrated circuit.

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