Printed circuit board

Abstract

To provide a printed circuit board that comprises a main printed circuit board and a flexible printed circuit board where a damper detection pattern is formed, and that can make compact the structure for ensuring the security of the main printed circuit board.SOLUTION: A flexible printed circuit board 3 of a printed circuit board comprises a box part 3a formed in a box shape, and fixed parts 3b to 3d spreading on an outer peripheral side of the box part 3a. Internal lands 35 to 38 forming one end part of a tamper detection part are electrically connected to the main printed circuit board and arranged inside the box part 3a, and external lands 45 to 48 forming the other end part of the tamper detection part are formed at the fixed parts 3b to 3d, fixed to the main printed circuit board, and also electrically connected to the main printed circuit board. The external lands 45 to 48 are insulated from one another, and the external lands 45 to 48 are not electrically connected to other external lands 45 to 48.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a printed circuit board. [Background technology]

[0002] Conventionally, manual card readers have been known in which a card is manually inserted and removed to read data recorded on the card and write data to the card (see, for example, Patent Document 1). The card reader described in Patent Document 1 comprises a card reader main body and a case body that covers the card reader main body. The card reader main body comprises an IC contact block having a plurality of IC contact springs, and the IC contact springs contact external connection terminals of an IC chip formed on the card. A printed circuit board to which a cable drawn from the IC contact block is connected is attached to the card reader main body. The case body comprises a second case body that covers the printed circuit board.

[0003] In the card reader described in Patent Document 1, a flexible printed circuit board is attached to the inner surface of the second case body. A tamper detection pattern is formed on the flexible printed circuit board to detect disconnections and short circuits in the flexible printed circuit board. The flexible printed circuit board is attached to the second case body along the inner surface of the second case body so as to cover the entire inner surface of the second case body, and the printed circuit board is covered by the flexible printed circuit board. In addition, the flexible printed circuit board is arranged inside the case body and cannot be seen from outside the card reader. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-225863 Summary of the Invention [Problem to be solved by the invention]

[0005] In the card reader described in Patent Document 1, the printed circuit board is covered with a flexible printed circuit board on which a tamper detection pattern is formed, making it possible to detect any attempted fraudulent activity on the printed circuit board using the tamper detection pattern. In other words, this card reader ensures the security of the printed circuit board. However, in this card reader, the flexible printed circuit board is attached to a second case body, and a second case body is required to cover the printed circuit board with the flexible printed circuit board. Therefore, in this card reader, it is difficult to miniaturize the configuration for ensuring the security of the printed circuit board.

[0006] Therefore, the object of the present invention is to provide a printed circuit board that includes a main printed circuit board and a flexible printed circuit board on which a tamper detection pattern is formed, and that makes it possible to miniaturize the configuration for ensuring the security of the main printed circuit board. [Means for solving the problem]

[0007] In order to solve the above problems, the printed circuit board of the present invention comprises a main printed circuit board and a flexible printed circuit board fixed to the main printed circuit board, the flexible printed circuit board having a box portion formed in a box shape with an opening on the main printed circuit board side and a fixed portion extending to the outer periphery of the box portion and fixed to the main printed circuit board, a plurality of tamper detection patterns formed on the flexible printed circuit board, the tamper detection patterns being provided to detect at least one of a break in the tamper detection pattern itself and a short circuit with another tamper detection pattern, an internal land forming one end of the tamper detection pattern being electrically connected to the main printed circuit board and being positioned inside the box portion, an external land forming the other end of the tamper detection pattern being formed on the fixed portion and fixed to the main printed circuit board and being electrically connected to the main printed circuit board, each of the plurality of external lands being insulated from each other, and the external lands not being electrically connected to each other.

[0008] In the printed circuit board of the present invention, the flexible printed circuit board on which multiple tamper detection patterns are formed has a fixed portion that is fixed to the main printed circuit board, and the flexible printed circuit board is directly fixed to the main printed circuit board. Therefore, in the present invention, there is no need to provide a second case body to which the flexible printed circuit board is attached, as in the card reader described in Patent Document 1. Therefore, in the present invention, it is possible to miniaturize the configuration for ensuring the security of the main printed circuit board.

[0009] In addition, in the present invention, the external land forming the other end of the tamper detection pattern is formed on the fixed portion, fixed to the main printed circuit board, and electrically connected to the main printed circuit board. Therefore, in the present invention, when a criminal tries to remove the flexible printed circuit board from the main printed circuit board in order to commit fraud on the main printed circuit board and peels the external land from the main printed circuit board, it is possible to detect an attempt to remove the flexible printed circuit board from the main printed circuit board. Therefore, in the present invention, it is possible to improve the security of the main printed circuit board.

[0010] Furthermore, in the present invention, since the multiple external lands are insulated from each other and are not electrically connected to each other, even if a criminal electrically connects the external lands formed on the fixed portion, the predetermined tamper detection pattern itself cannot be short-circuited between the electrically connected external lands. In other words, in the present invention, even if a criminal electrically connects the external lands, the function of the tamper detection pattern cannot be impaired. Therefore, in the present invention, even if the external lands for directly fixing the flexible printed circuit board to the main printed circuit board are formed on the fixed portion located outside the box portion of the flexible printed circuit board, it is possible to improve the security of the main printed circuit board.

[0011] In the present invention, for example, the main printed circuit board is formed in a flat plate shape, the flexible printed circuit board has a board connection portion where an internal land is formed, the shape of the box portion when viewed from the thickness direction of the main printed circuit board is rectangular or square, the fixed portion is connected to each of the three sides of the box portion which has a rectangular or square shape when viewed from the thickness direction of the main printed circuit board, and the board connection portion is connected to the remaining side of the box portion to which the fixed portion is not connected and is arranged inside the box portion.

[0012] In this case, it is preferable that at least two external lands are formed on each of the three fixed portions. With this configuration, when a criminal attempts to remove the flexible printed circuit board from the main printed circuit board in order to commit fraud on the main printed circuit board, the external lands are more likely to peel off from the main printed circuit board. Therefore, it becomes easier to detect when the flexible printed circuit board is about to be removed from the main printed circuit board. In other words, it becomes easier to detect fraudulent acts by criminals.

[0013] In the present invention, the flexible printed circuit board includes a tamper detection pattern layer on which a plurality of tamper detection patterns are formed, and a ground pattern layer on which a ground pattern covering the plurality of tamper detection patterns is formed from one side in the thickness direction of the flexible printed circuit board and overlaps the tamper detection pattern layer, and the tamper detection pattern layer is preferably arranged on the main printed circuit board side in the box portion and the fixed portion. That is, in the present invention, the ground pattern layer covering the plurality of tamper detection patterns is preferably arranged outside the tamper detection pattern layer in the box portion and the fixed portion.

[0014] With this configuration, the tamper detection pattern layer is not visible from the outside of the box portion and the fixed portion. Therefore, it is difficult for criminals to recognize that multiple tamper detection patterns are formed on the flexible printed circuit board. Furthermore, with this configuration, even if a criminal were to poke a hole in the flexible printed circuit board from the outside of the box portion in order to commit fraud on the main printed circuit board, the copper foil of the ground pattern would short-circuit adjacent tamper detection patterns even if the tamper detection patterns were not broken. Therefore, it is easier to detect the criminal's fraud. [Effects of the Invention]

[0015] As described above, the present invention makes it possible to miniaturize the configuration for ensuring the security of a main printed circuit board in a printed circuit board that includes a main printed circuit board and a flexible printed circuit board on which a tamper detection pattern is formed. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view of a printed circuit board according to an embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view of the main printed circuit board shown in FIG. [Figure 3] FIG. 2 is a block diagram for explaining the configuration of the main printed circuit board shown in FIG. [Figure 4] 2A is a perspective view showing the flexible printed circuit board shown in FIG. 1 from a different direction, and FIG. 2B is a development view of the flexible printed circuit board shown in FIG. [Figure 5] FIG. 4B is an enlarged view of part E in FIG. [Figure 6] FIG. 5 is a cross-sectional view of the flexible printed circuit board shown in FIG. [Figure 7] FIG. 5 is a block diagram for explaining the configuration of the flexible printed circuit board shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] (Printed circuit board configuration) FIG. 1 is a perspective view of a printed circuit board 1 according to an embodiment of the present invention. FIG. 2 is a perspective view of a main printed circuit board 2 shown in FIG. 1. FIG. 3 is a block diagram for explaining the configuration of the main printed circuit board 2 shown in FIG. 1. FIG. 4(A) is a perspective view showing the flexible printed circuit board 3 shown in FIG. 1 from a different direction, and FIG. 4(B) is a development view of the flexible printed circuit board 3 shown in FIG. 4(A). FIG. 5 is an enlarged view of a portion E in FIG. 4(B). FIG. 6 is a cross-sectional view of the flexible printed circuit board 3 shown in FIG. 4. FIG. 7 is a block diagram for explaining the configuration of the flexible printed circuit board 3 shown in FIG. 4.

[0019] The printed circuit board 1 of this embodiment is used to process data communicated between, for example, an information storage medium such as a card, a mobile device such as a smartphone, and the like, and is mounted on a payment terminal for use. The printed circuit board 1 includes a main printed circuit board 2 and a flexible printed circuit board 3 (hereinafter referred to as "FPC3") for ensuring the security of the main printed circuit board 2. The printed circuit board 1 of this embodiment is composed of the main printed circuit board 2 and the FPC3.

[0020] The FPC 3 is fixed to the main printed circuit board 2. A plurality of tamper detection patterns P1, P3, P5 to P8 are formed on the FPC 3 (see FIG. 7). In this embodiment, six tamper detection patterns P1, P3, P5 to P8 are formed on the FPC 3. The tamper detection patterns P1, P3, P5 to P8 are provided to detect a break in the tamper detection patterns P1, P3, P5 to P8 themselves and a short circuit between the tamper detection patterns P1, P3, P5 to P8 and other tamper detection patterns P1, P3, P5 to P8.

[0021] The main printed circuit board 2 is a rigid board having rigidity, such as a glass epoxy board. The main printed circuit board 2 is formed in a flat plate shape. Specifically, the main printed circuit board 2 is formed in a rectangular flat plate shape. As described above, the printed circuit board 1 is mounted on, for example, a payment terminal. The main printed circuit board 2 is electrically connected to at least one of, for example, an antenna coil for contactless data communication with a card, smartphone, etc., an IC contact spring for contacting an external connection terminal of an IC contact formed on the card to communicate data, and a magnetic head for reading magnetic data recorded on the card.

[0022] Furthermore, a tamper detection circuit 6 is mounted on the main printed circuit board 2 to detect when the tamper detection patterns P1, P3, P5 to P8 are disconnected and when the tamper detection patterns P1, P3, P5 to P8 are short-circuited with other tamper detection patterns P1, P3, P5 to P8. The tamper detection circuit 6 is a CPU (Central Processing Unit). The tamper detection circuit 6 is mounted on one side of the main printed circuit board 2. The tamper detection circuit 6 generates a tamper detection signal that flows through the tamper detection patterns P1, P3, P5 to P8 to detect when the tamper detection patterns P1, P3, P5 to P8 are disconnected and when the tamper detection patterns P1, P3, P5 to P8 are short-circuited with other tamper detection patterns P1, P3, P5 to P8.

[0023] A plurality of signal patterns P11 to P18 and P25 to P28 are formed on the main printed circuit board 2 for transmitting tamper detection signals generated by the tamper detection circuit 6 to the tamper detection patterns P1, P3, and P5 to P8. In this embodiment, twelve signal patterns P11 to P18 and P25 to P28 are formed on the main printed circuit board 2. One ends of the signal patterns P11 to P18 and P25 to P28 are connected to the tamper detection circuit 6. Also formed on the main printed circuit board 2 are a terminal 11 forming the other end of the signal pattern P11, a terminal 12 forming the other end of the signal pattern P12, a terminal 13 forming the other end of the signal pattern P13, and a terminal 14 forming the other end of the signal pattern P14.

[0024] In addition, the main printed circuit board 2 is formed with a land (port) 15 that forms the other end of the signal pattern P15, a land 16 that forms the other end of the signal pattern P16, a land 17 that forms the other end of the signal pattern P17, a land 18 that forms the other end of the signal pattern P18, a land 25 that forms the other end of the signal pattern P25, a land 26 that forms the other end of the signal pattern P26, a land 27 that forms the other end of the signal pattern P27, and a land 28 that forms the other end of the signal pattern P28.

[0025] Furthermore, lands 21 and 23 for fixing the FPC 3 to the main printed circuit board 2 are formed on the main printed circuit board 2. The lands 21 and 23 are not electrically connected to the tamper detection circuit 6. The terminals 11 to 14 and the lands 15 to 18, 21, 23, and 25 to 28 are formed on one side of the main printed circuit board 2 on which the tamper detection circuit 6 is mounted. In the following description, the side of the main printed circuit board 2 on which the lands 15 to 18, 21, 23, and 25 to 28 are formed will be referred to as the front side 2a, and the side opposite the front side 2a will be referred to as the back side. Note that the tamper detection circuit 6 and terminals 11 to 14 are not shown in FIG. 2.

[0026] The main printed circuit board 2 is a multi-layer board. The main printed circuit board 2 includes a circuit pattern layer on which signal patterns P11 to P18 and P25 to P28 are formed, a tamper detection pattern layer on which multiple tamper detection patterns are formed, and a ground pattern layer on which a ground pattern is formed. The multiple tamper detection patterns formed on the tamper detection pattern layer of the main printed circuit board 2 are provided to detect when a tamper detection pattern itself is broken or when a tamper detection pattern is short-circuited with another tamper detection pattern.

[0027] The tamper detection pattern layer is arranged closer to the back surface of the main printed circuit board 2 than the circuit pattern layer, and the ground pattern layer is arranged closer to the back surface of the main printed circuit board 2 than the tamper detection pattern layer. The multiple tamper detection patterns formed on the tamper detection pattern layer cover the areas of the main printed circuit board 2 that need to ensure security from the back surface side of the main printed circuit board 2. In this embodiment, the tamper detection patterns are formed over the entire area of ​​the main printed circuit board 2. The ground pattern formed on the ground pattern layer covers the multiple tamper detection patterns formed on the tamper detection pattern layer from the back surface side of the main printed circuit board 2. In this embodiment, the ground pattern is formed over the entire area of ​​the main printed circuit board 2.

[0028] The FPC 3 is fixed to the front surface 2a of the main printed circuit board 2. The FPC 3 includes a box portion 3a formed in a box shape that opens on the side facing the main printed circuit board 2, fixed portions 3b to 3d that extend around the outer periphery of the box portion 3a and are fixed to the main printed circuit board 2, and a board connection portion 3e that is arranged inside the box portion 3a. The FPC 3 is formed by bending a flexible, flat, film-like flexible printed circuit board (see FIG. 4(B)) into a predetermined shape and fixing it (see FIG. 4(A)).

[0029] The box portion 3a is formed in the shape of a flat rectangular box. When viewed from the thickness direction of the main printed circuit board 2, the shape of the box portion 3a is rectangular. The box portion 3a covers the area of ​​the main printed circuit board 2 that needs to be secured from the front surface 2a side of the main printed circuit board 2. Specifically, the box portion 3a covers the tamper detection circuit 6 and the like from the front surface 2a side. Furthermore, in this embodiment, as described above, the main printed circuit board 2 is provided with a tamper detection pattern layer, and the area of ​​the main printed circuit board 2 that needs to be secured is covered from both sides in the thickness direction of the main printed circuit board 2 by the tamper detection pattern layer of the main printed circuit board 2 and the box portion 3a.

[0030] The fixed portions 3b to 3d are connected to the three sides of the box portion 3a, which has a rectangular shape when viewed from the thickness direction of the main printed circuit board 2. That is, the fixed portions 3b to 3d are formed by portions bent outward from the three sides of the opening of the box portion 3a, and the fixed portions 3b to 3d extend in a flange-like shape from the three sides of the opening of the box portion 3a toward the outer periphery of the box portion 3a. The board connection portion 3e is connected to the remaining side of the box portion 3a to which the fixed portions 3b to 3d are not connected. That is, the portion bent inward from the remaining side of the opening of the box portion 3a forms the board connection portion 3e. The FPC 3 of this embodiment is composed of the box portion 3a, the three fixed portions 3b to 3d, and the board connection portion 3e.

[0031] The fixed portions 3b to 3d are formed in an elongated rectangular shape. The board connection portion 3e is composed of a land formation portion 3f formed in an elongated rectangular shape and an elongated strip-shaped portion 3g extending from the land formation portion 3f toward the inside of the box portion 3a. The fixed portion 3b is connected to one of the long sides of the box portion 3a, which has a rectangular shape when viewed in the thickness direction of the main printed circuit board 2, and the fixed portion 3c is connected to the other long side of the box portion 3a. The fixed portion 3d is connected to one of the short sides of the box portion 3a, and the board connection portion 3e is connected to the other short side of the box portion 3a. The fixed portions 3b to 3d and the board connection portion 3e are in contact with the main printed circuit board 2.

[0032] The FPC 3 also includes a tamper detection pattern layer 29 on which six tamper detection patterns P1, P3, P5 to P8 are formed, and a ground pattern layer 30 on which a ground pattern covering the six tamper detection patterns P1, P3, P5 to P8 is formed from one side in the thickness direction of the FPC 3 (see FIG. 6). The tamper detection pattern layer 29 and the ground pattern layer 30 overlap in the thickness direction of the FPC 3. An insulating layer (not shown) is disposed between the tamper detection pattern layer 29 and the ground pattern layer 30. The tamper detection pattern layer 29 forms one side of the FPC 3, and the ground pattern layer 30 forms the other side of the FPC 3. The surfaces of the tamper detection pattern layer 29 and the ground pattern layer 30 are covered with an insulating coating.

[0033] On the tamper detection pattern layer 29, six tamper detection patterns P1, P3, P5 to P8 are routed irregularly. Furthermore, the tamper detection patterns P1, P3, P5 to P8 are routed throughout the entire area of ​​the tamper detection pattern layer 29. That is, the tamper detection patterns P1, P3, P5 to P8 are routed in the box portion 3a, the fixed portions 3b to 3d, and the board connection portion 3e. On the ground pattern layer 30, a ground pattern is formed throughout the entire area of ​​the ground pattern layer 30. The tamper detection pattern layer 29 is arranged on the main printed circuit board 2 side in the box portion 3a and the fixed portions 3b to 3d. That is, the ground pattern layer 30 is arranged outside the tamper detection pattern layer 29 in the box portion 3a and the fixed portions 3b to 3d, and covers the tamper detection pattern layer 29 from the outside.

[0034] The FPC 3 is formed with a terminal 31 forming one end of the tamper detection pattern P1, a terminal 32 forming the other end of the tamper detection pattern P1, a terminal 33 forming one end of the tamper detection pattern P3, and a terminal 34 forming the other end of the tamper detection pattern P3. The FPC 3 also is formed with an internal land (port) 35 forming one end of the tamper detection pattern P5, an internal land 36 forming one end of the tamper detection pattern P6, an internal land 37 forming one end of the tamper detection pattern P7, and an internal land 38 forming one end of the tamper detection pattern P8.

[0035] Furthermore, the FPC 3 is formed with an external land (port) 45 that forms the other end of the tamper detection pattern P5, an external land 46 that forms the other end of the tamper detection pattern P6, an external land 47 that forms the other end of the tamper detection pattern P7, and an external land 48 that forms the other end of the tamper detection pattern P8. The FPC 3 is also formed with lands 41 and 43 for fixing the FPC 3 to the main printed circuit board 2. The lands 41 and 43 are not electrically connected to the tamper detection patterns P1, P3, and P5 to P8.

[0036] As shown in Fig. 5, terminals 31 to 34 are formed at the tip of strip portion 3g. Internal lands 35 to 38 are formed in land formation portion 3f. That is, internal lands 35 to 38 are formed in board connection portion 3e. Furthermore, terminals 31 to 34 and internal lands 35 to 38 are disposed inside box portion 3a and are not exposed outside box portion 3a.

[0037] The terminals 31 to 34 are arranged at intervals in the short-side direction of the strip-shaped portion 3g, which has an elongated strip shape. The terminals 31, 33, 32, and 34 are arranged in this order in the short-side direction of the strip-shaped portion 3g. The internal lands 35 to 38 are arranged at intervals in the long-side direction of the land forming portion 3f, which has an elongated rectangular shape. The internal lands 35 to 38 are arranged in this order from the fixed portion 3b side in the long-side direction of the land forming portion 3f.

[0038] Lands 41, 43 and outer lands 45-48 are formed on fixed portions 3b-3d. Specifically, land 41 and outer land 48 are formed on fixed portion 3b, land 43 and outer land 45 are formed on fixed portion 3c, and outer lands 46, 47 are formed on fixed portion 3d. Lands 41, 43 and outer lands 45-48 are exposed outside box portion 3a.

[0039] Land 41 and outer land 48 are spaced apart in the long-side direction of fixed portion 3b, which is formed in an elongated rectangular shape. Land 41 is located on the board connecting portion 3e side, and outer land 48 is located on the fixed portion 3d side. Land 43 and outer land 45 are spaced apart in the long-side direction of fixed portion 3c. Outer land 45 is located on the board connecting portion 3e side, and land 43 is located on the fixed portion 3d side. Outer lands 46 and 47 are spaced apart in the long-side direction of fixed portion 3d. Outer land 46 is located on the fixed portion 3c side, and outer land 47 is located on the fixed portion 3b side.

[0040] Terminal 31 is electrically connected to terminal 11, terminal 32 is electrically connected to terminal 12, terminal 33 is electrically connected to terminal 13, and terminal 34 is electrically connected to terminal 14. Furthermore, internal land 35 is electrically connected to land 15, internal land 36 is electrically connected to land 16, internal land 37 is electrically connected to land 17, and internal land 38 is electrically connected to land 18. In other words, terminals 31 to 34 and internal lands 35 to 38 are electrically connected to the main printed circuit board 2.

[0041] In this embodiment, for example, when the tip of strip portion 3g is inserted into a connector (not shown) mounted on main printed circuit board 2, terminal 31 comes into contact with terminal 11 and is electrically connected, terminal 32 comes into contact with terminal 12 and is electrically connected, terminal 33 comes into contact with terminal 13 and is electrically connected, and terminal 34 comes into contact with terminal 14. On main printed circuit board 2, terminals 11 to 14 are arranged at positions corresponding to terminals 31 to 34, respectively.

[0042] The internal land 35 is soldered and fixed to the land 15, the internal land 36 is soldered and fixed to the land 16, the internal land 37 is soldered and fixed to the land 17, and the internal land 38 is soldered and fixed to the land 18. That is, the internal lands 35 to 38 are fixed to the main printed circuit board 2. On the main printed circuit board 2, the lands 15 to 18 are arranged at positions corresponding to the internal lands 35 to 38, respectively.

[0043] The external land 45 is electrically connected to the land 25, the external land 46 is electrically connected to the land 26, the external land 47 is electrically connected to the land 27, and the external land 48 is electrically connected to the land 28. In other words, the external lands 45 to 48 are electrically connected to the main printed circuit board 2.

[0044] Furthermore, land 41 is soldered and fixed to land 21, land 43 is soldered and fixed to land 23, outer land 45 is soldered and fixed to land 25, outer land 46 is soldered and fixed to land 26, outer land 47 is soldered and fixed to land 27, and outer land 48 is soldered and fixed to land 28. That is, lands 41, 43 and outer lands 45 to 48 are fixed to the main printed circuit board 2. On the main printed circuit board 2, lands 21, 23, 25 to 28 are respectively arranged at positions corresponding to lands 41, 43 and outer lands 45 to 48.

[0045] Tamper detection pattern P1 is electrically connected to signal patterns P11 and P12. Tamper detection pattern P3 is electrically connected to signal patterns P13 and P14. Tamper detection pattern P5 is electrically connected to signal patterns P15 and P25, tamper detection pattern P6 is electrically connected to signal patterns P16 and P26, tamper detection pattern P7 is electrically connected to signal patterns P17 and P27, and tamper detection pattern P8 is electrically connected to signal patterns P18 and P28.

[0046] Tamper detection pattern P1, tamper detection pattern P3, tamper detection pattern P5, tamper detection pattern P6, tamper detection pattern P7, and tamper detection pattern P8 are insulated from one another and are not electrically connected to one another. That is, the four external lands 45 to 48 are insulated from one another and are not electrically connected to the other external lands 45 to 48. Furthermore, each of the external lands 45 to 48 is insulated from the two lands 41 and 43 and is not electrically connected to the lands 41 and 43.

[0047] The tamper detection signal flowing through tamper detection pattern P1, the tamper detection signal flowing through tamper detection pattern P3, the tamper detection signal flowing through tamper detection pattern P5, the tamper detection signal flowing through tamper detection pattern P6, the tamper detection signal flowing through tamper detection pattern P7, and the tamper detection signal flowing through tamper detection pattern P8 are different from one another. That is, the tamper detection circuit 6 generates different tamper detection signals for each of the tamper detection patterns P1, P3, P5, P6, P7, and P8.

[0048] In this embodiment, if a criminal takes some action to illegally obtain data from main printed circuit board 2, such as breaking tamper detection patterns P1, P3, P5-P8, shorting tamper detection patterns P1, P3, P5-P8 with other tamper detection patterns P1, P3, P5-P8, or peeling external lands 45-48 from lands 25-28, the tamper detection signal will stop flowing, and tamper detection circuit 6 will detect that illegal activity is occurring. If illegal activity is detected, main printed circuit board 2 will execute predetermined abnormality processing, such as erasing data stored on main printed circuit board 2 or rendering main printed circuit board 2 unusable, thereby preventing illegal acquisition of data from main printed circuit board 2.

[0049] (Main effect of this form) As described above, in this embodiment, the FPC 3 for ensuring the security of the main printed circuit board 2 has fixed portions 3b to 3d that are fixed to the main printed circuit board 2, and the FPC 3 is directly fixed to the main printed circuit board 2. Therefore, in this embodiment, there is no need to provide a case body to which the FPC 3 is attached, as in the card reader described in the above Patent Document 1. Therefore, in this embodiment, it is possible to miniaturize the configuration for ensuring the security of the main printed circuit board 2.

[0050] In this embodiment, external lands 45-48, which form the other ends of tamper detection patterns P5-P8, are formed on fixed portions 3b-3d and are fixed to and electrically connected to main printed circuit board 2. Therefore, in this embodiment, when a criminal attempts to remove FPC 3 from main printed circuit board 2 and peels external lands 45-48 from lands 25-28 in order to commit fraud on main printed circuit board 2, tamper detection circuit 6 detects the fraud, as described above. Furthermore, in this embodiment, when fraud is detected, predetermined abnormality processing, such as erasing data stored in main printed circuit board 2, is executed. Therefore, in this embodiment, it is possible to improve the security of main printed circuit board 2.

[0051] In this embodiment, the four external lands 45 to 48 are insulated from one another and are not electrically connected to the other external lands 45 to 48. Therefore, in this embodiment, even if a criminal electrically connects the external lands 45 to 48 formed on the fixed portions 3b to 3d, he or she cannot short-circuit the tamper detection pattern P5 itself, the tamper detection pattern P6 itself, the tamper detection pattern P7 itself, or the tamper detection pattern P8 itself between the electrically connected external lands 45 to 48.

[0052] For example, even if external land 45 and external land 46 are electrically connected, tamper detection pattern P5 itself cannot be short-circuited, and tamper detection pattern P6 itself cannot be short-circuited. Furthermore, even if external land 47 and external land 48 are electrically connected, tamper detection pattern P7 itself cannot be short-circuited, and tamper detection pattern P8 itself cannot be short-circuited. In other words, in this embodiment, even if a criminal electrically connects external lands 45 to 48, the functions of tamper detection patterns P5 to P8 cannot be impaired.

[0053] Therefore, in this embodiment, even if the external lands 45-48 for directly fixing the FPC 3 to the main printed circuit board 2 are formed on the fixing portions 3b-3d arranged on the outside of the box portion 3a, it is possible to improve the security of the main printed circuit board 2. In this embodiment, if a criminal electrically connects the external lands 45-48 to each other, it is detected that the tamper detection patterns P5-P8 have been short-circuited with other tamper detection patterns P5-P8.

[0054] In this embodiment, in the box portion 3a and the fixed portions 3b to 3d, the ground pattern layer 30 is disposed outside the tamper detection pattern layer 29 and covers the tamper detection pattern layer 29 from the outside. Therefore, in this embodiment, the tamper detection patterns P1, P3, P5 to P8 cannot be seen from the outside of the box portion 3a and the fixed portions 3b to 3d. Therefore, in this embodiment, it is difficult for a criminal to recognize that the tamper detection patterns P1, P3, P5 to P8 are formed on the FPC 3.

[0055] Furthermore, in this embodiment, in the box portion 3a and the fixed portions 3b to 3d, the ground pattern layer 30 is disposed outside the tamper detection pattern layer 29. Therefore, when a criminal, for example, punches a hole in the FPC 3 from outside the box portion 3a in order to commit tampering with the main printed circuit board 2, the copper foil of the ground pattern can short-circuit adjacent tamper detection patterns P1, P3, P5 to P8 even if the tamper detection patterns P1, P3, P5 to P8 are not broken. Therefore, in this embodiment, it is easier to detect the criminal's tampering.

[0056] (Other embodiments) The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications can be made without departing from the spirit of the present invention.

[0057] In the above-described embodiment, the number of tamper detection patterns formed on FPC 3 may be 2 or more and 5 or less. Also, in the above-described embodiment, the number of tamper detection patterns formed on FPC 3 may be 7 or more. If the number of tamper detection patterns formed on FPC 3 is 8 or more, it is preferable that at least two external lands are formed on each of the three fixed portions 3b to 3d.

[0058] If at least two external lands are formed on each of the three fixed portions 3b to 3d, when a criminal attempts to remove the FPC 3 from the main printed circuit board 2 in order to commit fraud on the main printed circuit board 2, the external lands are likely to come off from the lands formed on the main printed circuit board 2. This makes it easier to detect attempts to remove the FPC 3 from the main printed circuit board 2. In other words, it becomes easier to detect fraud by a criminal.

[0059] In the above-described embodiment, the tamper detection patterns P1, P3, P5 to P8 may be provided to detect only one of a break in the tamper detection pattern P1, P3, P5 to P8 itself and a short circuit between the tamper detection pattern P1, P3, P5 to P8 and another tamper detection pattern P1, P3, P5 to P8. Also, in the above-described embodiment, the tamper detection patterns formed on the tamper detection pattern layer of the main printed circuit board 2 may be provided to detect only one of a break in the tamper detection pattern itself and a short circuit between the tamper detection pattern and another tamper detection pattern.

[0060] In the embodiment described above, two lands 41, 43 for fixing the FPC 3 to the main printed circuit board 2 are formed on the FPC 3, but one land for fixing the FPC 3 to the main printed circuit board 2 may be formed on the FPC 3, or three or more lands may be formed on the FPC 3. Also, in the embodiment described above, the lands 41, 43 do not have to be formed on the FPC 3.

[0061] In the above-described embodiment, the shape of the box portion 3a when viewed in the thickness direction of the main printed circuit board 2 may be square. Furthermore, in the above-described embodiment, the main printed circuit board 2 may be a flexible printed circuit board. Furthermore, in the above-described embodiment, the printed circuit board 1 may be mounted and used in a device other than a payment terminal. For example, the printed circuit board 1 may be mounted and used in a manual or card-carrying card reader. [Explanation of symbols]

[0062] 1 Printed circuit board 2 Main printed circuit board 3 FPC (Flexible Printed Circuit) 3a Hakobe 3b~3d Fixed part 3e Board connection part 29 Tamper Detection Pattern Layer 30 Ground Pattern Layer 35~38 Internal Land 45~48 Outer Land P5~P8 Tamper detection patterns

Claims

1. a main printed circuit board and a flexible printed circuit board fixed to the main printed circuit board; the flexible printed circuit board includes a box portion formed in a box shape with an opening on the main printed circuit board side, and a fixed portion extending outward from the outer periphery of the box portion and fixed to the main printed circuit board, A plurality of tamper detection patterns are formed on the flexible printed circuit board, the tamper detection pattern is provided to detect at least one of a break in the tamper detection pattern itself and a short circuit with another tamper detection pattern; an internal land forming one end of the tamper detection pattern is electrically connected to the main printed circuit board and is disposed inside the box portion; an external land forming the other end of the tamper detection pattern is formed in the fixed portion, fixed to the main printed circuit board, and electrically connected to the main printed circuit board; A printed circuit board, characterized in that the plurality of external lands are insulated from one another and the external lands are not electrically connected to other external lands.

2. The main printed circuit board is formed in a flat plate shape, the flexible printed circuit board has a board connection portion where the internal land is formed, The box portion has a rectangular or square shape when viewed in the thickness direction of the main printed circuit board, the fixed portion is connected to each of three sides of the box portion, which has a rectangular or square shape when viewed in the thickness direction of the main printed circuit board; 2. The printed circuit board according to claim 1, wherein the board connection portion is connected to the remaining side of the box portion to which the fixed portion is not connected, and is disposed inside the box portion.

3. 3. The printed circuit board according to claim 2, wherein at least two of the external lands are formed on each of the three fixed portions.

4. the flexible printed circuit board includes a tamper detection pattern layer on which a plurality of the tamper detection patterns are formed, and a ground pattern layer on which a ground pattern covering the plurality of tamper detection patterns is formed from one side in a thickness direction of the flexible printed circuit board and which overlaps the tamper detection pattern layer; 4. The printed circuit board according to claim 1, wherein the tamper detection pattern layer is arranged on the main printed circuit board side of the box portion and the fixed portion.

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