Tamper-resistant flexible circuit board and payment terminal
Patent Information
- Application Number
- CN202522436040.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-17
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2035-11-17
AI Technical Summary
[0002]支付终端的信息安全十分重要，在相关技术中，主要使用防拆mesh来保护内层电路，可将防拆mesh粘贴在屏和壳体上，当拆卸屏幕或壳体时防拆mesh损坏，从而达到防拆效果，这种防拆mesh在常温情况下会起到很好的保护效果，但是当支付终端在高温环境下拆卸时，防拆mesh的背胶在高温状态下软化、粘接强度下降，防拆效果和保护力度较差，会出现屏幕被拆掉，防拆mesh没有被损坏的情况，因此，防拆mesh的结构设计有必要进行改进
[0006]根据本实用新型实施例的防拆柔性电路板，防拆段具有mesh线路和第一切缝，过渡段具有第二切缝，第一切缝和第二切缝在防拆段和过渡段的连接处相交，即便是在高温环境下揭下防拆柔性电路板时，mesh线路在与第一切缝相邻的位置也容易损坏，以增加防拆柔性电路板无损拆卸的难度，降低防拆柔性电路板防拆功能失效的风险。
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Figure CN224844402U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of payment terminal technology, and more specifically, to an anti-tamper flexible circuit board and a payment terminal. Background Technology
[0002] Information security of payment terminals is of paramount importance. In related technologies, tamper-proof mesh is primarily used to protect the inner circuitry. This mesh is adhered to the screen and housing; when the screen or housing is removed, the mesh is damaged, thus achieving tamper protection. While this type of mesh provides good protection at room temperature, when the payment terminal is disassembled in a high-temperature environment, the adhesive on the mesh softens, its bonding strength decreases, and the tamper-proof effect and protection weaken. This can result in situations where the screen is removed but the mesh remains undamaged. Therefore, the structural design of tamper-proof mesh needs improvement. Utility Model Content
[0003] This invention aims to at least partially solve one of the aforementioned technical problems in the prior art. To this end, this invention proposes an tamper-proof flexible circuit board, which can reduce the risk of tamper-proof function failure.
[0004] This utility model also proposes a payment terminal with the aforementioned tamper-proof flexible circuit board.
[0005] According to an embodiment of the present invention, an anti-tamper flexible circuit board includes: a connector segment having a circuit connector; an anti-tamper segment having a mesh circuit and a first slit, the mesh circuit being laid on the outside of the first slit; and a transition segment connecting the connector segment and the anti-tamper segment, the circuit connector being connected to the mesh circuit through the transition segment, the transition segment having a second slit, the first slit and the second slit intersecting at the connection between the anti-tamper segment and the transition segment; wherein the connector segment, the anti-tamper segment, and the transition segment all have an adhesive backing layer on the same side in the thickness direction.
[0006] According to the embodiment of the present invention, the tamper-proof flexible circuit board has a mesh line and a first slit in the tamper-proof section and a second slit in the transition section. The first slit and the second slit intersect at the connection between the tamper-proof section and the transition section. Even when the tamper-proof flexible circuit board is peeled off in a high-temperature environment, the mesh line is easily damaged at the position adjacent to the first slit, thereby increasing the difficulty of non-destructive disassembly of the tamper-proof flexible circuit board and reducing the risk of failure of the tamper-proof function of the tamper-proof flexible circuit board.
[0007] According to some embodiments of the present invention, there are multiple first cuts and multiple second cuts, and each first cut and each second cut intersect at the same point.
[0008] According to some embodiments of the present invention, a plurality of first slits and a plurality of second slits extend radially around a common intersection point.
[0009] According to some embodiments of the present invention, the length of the first slit is greater than the length of the second slit.
[0010] According to some embodiments of the present invention, a plurality of first slits and a plurality of second slits correspond one-to-one, and the first slits and the corresponding second slits extend in the same direction.
[0011] According to some embodiments of the present invention, the number of the first cuts is two, and the included angle between the two first cuts is an acute angle.
[0012] According to some embodiments of the present invention, the joint segment has a reinforcing plate.
[0013] According to some embodiments of the present invention, the peel strength of the adhesive layer of the anti-tamper section and the transition section is P1, and the peel strength of the adhesive layer of the joint section is P2, satisfying the relationship: P1 > P2.
[0014] According to some embodiments of the present invention, the tamper-proof flexible circuit board further includes: a softening bending section, wherein the transition section is connected to the connector section through the softening bending section.
[0015] According to another embodiment of the present invention, a payment terminal includes: a motherboard, a display screen, a housing, and the aforementioned tamper-proof flexible circuit board. The motherboard and the display screen are mounted on the housing. The connector segment is bonded to the housing by its backing adhesive layer. The tamper-proof segment and the transition segment are bonded to the display screen by their corresponding backing adhesive layers. The circuit connector is connected to the motherboard.
[0016] According to the payment terminal of this utility model embodiment, the connector segment is bonded to the housing through its backing adhesive layer, and the anti-tamper segment and the transition segment are bonded to the display screen through their corresponding backing adhesive layers. The circuit connector is connected to the motherboard. The anti-tamper segment has a mesh circuit and a first slit, and the transition segment has a second slit. The first slit and the second slit intersect at the connection between the anti-tamper segment and the transition segment. Even when the anti-tamper flexible circuit board is peeled off in a high-temperature environment, the mesh circuit is easily damaged at the position adjacent to the first slit, thereby increasing the difficulty of non-destructive disassembly of the anti-tamper flexible circuit board, reducing the risk of failure of the anti-tamper function of the anti-tamper flexible circuit board, and thus helping to improve the security of the payment terminal.
[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the tamper-proof flexible circuit board according to an embodiment of the present utility model; Figure 2 This is a schematic diagram of the structure of a payment terminal according to an embodiment of the present utility model.
[0019] Figure label: Connector section 1; Circuit connector 11; Anti-tamper section 2; mesh line 21; first cut 22; Transition section 3; Second cut 31; Softened bending section 4; tear strip 5; 10 tamper-proof flexible circuit boards; Display screen 20; Housing 30; Payment terminal 100. Detailed Implementation
[0020] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.
[0021] In the description of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0023] The tamper-proof flexible circuit board 10 and payment terminal 100 according to embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0024] Reference Figure 1 and Figure 2 As shown, the tamper-proof flexible circuit board 10 includes: a connector section 1, an tamper-proof section 2, and a transition section 3. The connector section 1 has a circuit connector 11. The tamper-proof section 2 has a mesh line 21 and a first slit 22. The mesh line 21 is laid on the outside of the first slit 22. The transition section 3 connects the connector section 1 and the tamper-proof section 2. The circuit connector 11 is connected to the mesh line 21 through the transition section 3. The transition section 3 has a second slit 31. The first slit 22 and the second slit 31 intersect at the connection between the tamper-proof section 2 and the transition section 3. The connector section 1, the tamper-proof section 2, and the transition section 3 all have an adhesive backing layer on the same side in the thickness direction.
[0025] Specifically, the tamper-proof flexible circuit board 10 (FPC) can be bonded to the payment terminal 100 that needs to be prevented from being disassembled through an adhesive backing layer. The mesh line 21 in the tamper-proof section 2 can be a grid-like line with a line spacing of less than 0.3mm. The circuit connector 11 on the connector section 1 and the mesh line 21 form a detection circuit. The circuit connector 11 can be electrically connected to the motherboard of the payment terminal 100.
[0026] When the payment terminal 100 is in normal use, the adhesive position of the tamper-proof flexible circuit board 10 inside the payment terminal 100 remains unchanged, the detection circuit is normally connected, and the payment terminal 100 can work normally.
[0027] When the payment terminal 100 is disassembled, the separation of different components of the payment terminal 100 will cause the anti-tamper section 2 to be deformed or bent under force, thereby damaging the mesh line 21. The mesh line 21 will be short-circuited or open-circuited. When the motherboard detects that the detection circuit has a short circuit or open circuit, it can trigger a preset protection program, such as automatically clearing sensitive data such as keys, locking the system, or issuing an alarm, thereby preventing the leakage of critical information.
[0028] The first cut 22 penetrates the anti-tamper section 2 in the thickness direction. The mesh line 21 is adjacent to the first cut 22 and is laid on the outside of the first cut 22. The anti-tamper section 2 may be provided with a white edge to avoid the blade. The mesh line 21 is laid around the white edge to avoid the blade. The first cut 22 can be cut out in the white edge to avoid the blade by a cutting blade.
[0029] The second cut 31 penetrates the transition section 3 in the thickness direction. The second cut 31 can be cut in the transition section 3 by a cutter. The first cut 22 and the second cut 31 intersect at the connection between the anti-tamper section 2 and the transition section 3. When the adhesive is heated and softened, the mesh circuit 21 of the anti-tamper section 2 still has relatively reliable anti-tamper performance.
[0030] Understandably, when the adhesive is exposed to a high temperature above 100°C, it softens and its adhesiveness decreases, making it easier to peel off the tamper-proof flexible circuit board 10. However, due to the design of the first cut 22 and the second cut 31, the integrity of the tamper-proof section 2 and the transition section 3 decreases. During the peeling process, the tamper-proof section 2 is prone to different deformations on both sides of the first cut 22, resulting in damage to the mesh circuit 21. The transition section 3 is also prone to different deformations on both sides of the second cut 31. At the same time, since the first cut 22 and the second cut 31 intersect at the connection between the tamper-proof section 2 and the transition section 3, the transition section 3 exerts different tensions on both sides of the first cut 22, resulting in damage to the mesh circuit 21, thereby achieving better tamper-proof performance.
[0031] According to the embodiment of the present invention, the tamper-proof flexible circuit board 10 has a mesh line 21 and a first slit 22 in the tamper-proof section 2 and a second slit 31 in the transition section 3. The first slit 22 and the second slit 31 intersect at the connection between the tamper-proof section 2 and the transition section 3. Even when the tamper-proof flexible circuit board 10 is peeled off in a high-temperature environment, the mesh line 21 is easily damaged at the position adjacent to the first slit 22, thereby increasing the difficulty of non-destructive disassembly of the tamper-proof flexible circuit board 10 and reducing the risk of failure of the tamper-proof function of the tamper-proof flexible circuit board 10.
[0032] In some embodiments of this utility model, reference is made to Figure 1 and Figure 2 As shown, there are multiple first cuts 22 and multiple second cuts 31, and each first cut 22 and each second cut 31 intersect at the same point.
[0033] Specifically, multiple first cuts 22 can further reduce the integrity of the anti-disassembly section 2, making it easier for the anti-disassembly section 2 to break and deform when it is removed. Multiple second cuts 31 can further reduce the integrity of the transition section 3, making it easier for the transition section 3 to produce differentiated deformation when it is removed, so that the transition section 3 exerts differentiated tension on different areas of the anti-disassembly section 2, thereby causing the anti-disassembly section 2 to deform and be damaged.
[0034] Meanwhile, each first cut 22 and each second cut 31 intersect at the same point. That is to say, the multiple first cuts 22 are not parallel to each other, and the multiple second cuts 31 are not parallel to each other. When the tamper-proof flexible circuit board 10 is peeled off in any direction, the tamper-proof section 2 and the transition section 3 are prone to irregular deformation, which will lead to damage to the mesh line 21.
[0035] Optionally, the common intersection of each first slit 22 and each second slit 31 is located at the middle of the junction of the tamper-proof section 2 and the transition section 3, so as to improve the tamper-proof effect of the tamper-proof flexible circuit board 10 in all directions.
[0036] In some embodiments of this utility model, reference is made to Figure 1 and Figure 2 As shown, multiple first slits 22 and multiple second slits 31 extend radially from a common intersection point.
[0037] Specifically, the multiple first slits 22 and multiple second slits 31 can be constructed into "X" or "*" shaped slit structures that extend radially outward from a central point. This makes it difficult for the force used to peel off the tamper-proof flexible circuit board 10 to be parallel to the extension direction of each first slit 22 and each second slit 31 when it is peeled off, making the mesh circuit 21 of the tamper-proof flexible circuit board 10 more easily damaged when peeled off.
[0038] In some other embodiments of the present invention (not shown in the figures), a plurality of first slits 22 and a plurality of second slits 31 extend in a spiral shape around a common intersection point, so that when the tamper-proof flexible circuit board 10 is peeled off, the force of peeling off the tamper-proof flexible circuit board 10 is difficult to be parallel to the extension direction of the first slits 22 and the second slits 31, making the mesh circuit 21 of the tamper-proof flexible circuit board 10 more easily damaged when peeled off.
[0039] In some embodiments of this utility model, reference is made to Figure 1 and Figure 2 As shown, the length of the first cut 22 is greater than the length of the second cut 31. That is to say, the length of the first cut 22 is longer, which can increase the influence area of the first cut 22 on the anti-tamper section 2, making the anti-tamper section 2 easier to be damaged when it is peeled off. The length of the second cut 31 is shorter, so as to reduce the influence of the second cut 31 on the circuit layout in the transition section 3 and reduce the manufacturing difficulty of the transition section 3.
[0040] In some embodiments of this utility model, reference is made to Figure 1 and Figure 2 As shown, multiple first slits 22 and multiple second slits 31 correspond one-to-one, and the first slits 22 and the corresponding second slits 31 extend in the same direction.
[0041] Specifically, the first slit 22 and the corresponding second slit 31 extend in the same direction, and the first slit 22 and the second slit 31 intersect at the same point. That is to say, the first slit 22 and the corresponding second slit 31 are collinearly distributed. When manufacturing the tamper-proof flexible circuit board 10, the first slit 22 and the corresponding second slit 31 can be cut in the tamper-proof section 2 and the transition section 3 in one cut, so as to facilitate the manufacturing of the tamper-proof flexible circuit board 10.
[0042] In some embodiments of this utility model, reference is made to Figure 1 and Figure 2 As shown, there are two first cuts 22, and the angle between the two first cuts 22 is an acute angle.
[0043] Specifically, the two first cuts 22 with acute angles can form a ">" shaped cut structure. The tamper-proof section 2 forms a triangular area inside the two first cuts 22. The angle of the triangular area at the intersection of the two first cuts 22 is acute. When the tamper-proof section 2 is peeled off, the tamper-proof section 2 at the acute angle vertex of the triangular area is prone to being peeled off asynchronously with other positions. For example, the tamper-proof section 2 at the acute angle vertex of the triangular area is still stuck with adhesive. The part of the tamper-proof section 2 outside the triangular area is peeled off, making it difficult for different areas of the tamper-proof section 2 to be peeled off synchronously. The mesh line 21 is more likely to be damaged when peeled off, thus achieving a better tamper-proof effect.
[0044] In some embodiments of this utility model, the joint segment 1 has a reinforcing sheet.
[0045] Specifically, the reinforcing sheet can enhance the strength of connector segment 1. When the circuit connector 11 of connector segment 1 is connected to the motherboard via the zebra strip, the reinforcing sheet can reduce the deformation of connector segment 1 and provide rigid support for the circuit connector 11, reducing the risk of damage to connector segment 1. This helps to reduce the assembly difficulty of connector segment 1 and improve its reliability and service life. Optionally, the reinforcing sheet is a PI (polyimide) reinforcing sheet. The PI reinforcing sheet can increase the hardness of connector segment 1 and protect the circuit connector 11 part of connector segment 1. The PI reinforcing sheet has good heat resistance and good compatibility with FPC substrate. The reinforcing sheet can be yellow for easy identification and assembly.
[0046] In some embodiments of this utility model, the peel strength of the adhesive backing layer of the anti-disassembly section 2 and the transition section 3 is P1, and the peel strength of the adhesive backing layer of the joint section 1 is P2, satisfying the relationship: P1 > P2.
[0047] Specifically, the peel strength P1 of the adhesive layer of the anti-tamper section 2 and the transition section 3 is relatively high, so that the anti-tamper section 2 and the adjacent transition section 3 can be firmly bonded to the parts that need anti-tamper protection. It is more difficult to completely peel off the anti-tamper section 2 and the transition section 3 after they are pasted, thus achieving a better anti-tamper effect. The peel strength P2 of the adhesive layer of the joint section 1 is relatively low, so as to reduce the cost of the adhesive layer of the joint section 1.
[0048] Optionally, the adhesive backing of the anti-tamper section 2 and the transition section 3 can be 3M 468 adhesive. 3M 468 adhesive is non-conductive and has a long-term temperature resistance of 149℃ and a short-term temperature resistance of up to 204℃. It has high-strength adhesive properties, and its peel strength can be greater than or equal to 85N / 100mm. The adhesive backing of the joint section 1 can be non-conductive double-sided adhesive.
[0049] In some embodiments of this utility model, reference is made to Figure 1 and Figure 2As shown, the tamper-proof flexible circuit board 10 also includes a softening and bending section 4, and the transition section 3 is connected to the connector section 1 through the softening and bending section 4.
[0050] Specifically, the transition section 3 can be indirectly connected to the joint section 1 through the softening and bending section 4. The softening and bending section 4 can realize the mechanical structural connection between the transition section 3 and the joint section 1. The softening and bending section 4 also has a circuit connecting the transition section 3 and the joint section 1. The softening and bending section 4 has good flexibility. When the bonding plane of the anti-tamper section 2 and the transition section 3 is at different heights from the bonding plane of the joint section 1, the softening and bending section 4 can adapt to the change in height difference by bending. At the same time, the softening and bending section 4 does not have an adhesive backing layer, so that the softening and bending section 4 can adapt to the shape of the height difference by natural bending, thus avoiding the breakage of the softening and bending section 4.
[0051] In some embodiments of this utility model, reference is made to Figure 1 As shown, the tamper-proof flexible circuit board 10 also includes a tear strip 5. The tear strip 5 is pasted on the side of the tamper-proof flexible circuit board 10 away from the adhesive layer. A part of the tear strip 5 extends out of the tamper-proof flexible circuit board 10. The tear strip 5 can assist in the pasting and positioning of the tamper-proof flexible circuit board 10. After the tamper-proof flexible circuit board 10 is pasted, the tear strip 5 can be peeled off from the tamper-proof flexible circuit board 10.
[0052] Reference Figure 1 and Figure 2 As shown, a payment terminal 100 according to another embodiment of the present invention includes: a motherboard, a display screen 20, a housing 30 and an anti-tamper flexible circuit board 10 as described above. The motherboard and the display screen 20 are mounted on the housing 30. The connector segment 1 is bonded to the housing 30 by its backing adhesive layer. The anti-tamper segment 2 and the transition segment 3 are bonded to the display screen 20 by their corresponding backing adhesive layers. The circuit connector 11 is connected to the motherboard.
[0053] Specifically, the payment terminal 100 can be a POS (Point of Sales) machine, ATM, etc., and the display screen 20 can be an LCD (Liquid Crystal Display) display screen. When the payment terminal 100 is in normal use, the adhesive position of the tamper-proof flexible circuit board 10 inside the payment terminal 100 remains unchanged, the detection circuit is normally connected, and the payment terminal 100 can work normally.
[0054] When the payment terminal 100 is disassembled, the separation of the display screen 20 from the housing 30 will cause the anti-tamper section 2 to deform or bend under force, thereby damaging the mesh line 21. The mesh line 21 will short-circuit or open-circuit. When the motherboard detects that the detection circuit has short-circuited or open-circuited, it can trigger a preset protection program, such as automatically clearing sensitive data such as keys, locking the system, or issuing an alarm, thereby preventing the leakage of critical information.
[0055] According to the payment terminal 100 of this utility model embodiment, the connector segment 1 is bonded to the housing 30 by its backing adhesive layer, the anti-tamper segment 2 and the transition segment 3 are bonded to the display screen 20 by their corresponding backing adhesive layers, the circuit connector 11 is connected to the motherboard, the anti-tamper segment 2 has a mesh line 21 and a first slit 22, the transition segment 3 has a second slit 31, the first slit 22 and the second slit 31 intersect at the connection between the anti-tamper segment 2 and the transition segment 3, even when the anti-tamper flexible circuit board 10 is peeled off in a high temperature environment, the mesh line 21 is easily damaged at the position adjacent to the first slit 22, so as to increase the difficulty of non-destructive disassembly of the anti-tamper flexible circuit board 10, reduce the risk of failure of the anti-tamper function of the anti-tamper flexible circuit board 10, and thus help improve the security of the payment terminal 100.
[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.
[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A tamper-proof flexible circuit board, characterized in that, include: Connector segment (1), said connector segment (1) having a circuit connector (11); Anti-tamper section (2), the anti-tamper section (2) has a mesh line (21) and a first cut (22), the mesh line (21) is laid on the outside of the first cut (22); A transition section (3) is connected between the connector section (1) and the tamper-proof section (2). The circuit connector (11) is connected to the mesh line (21) through the transition section (3). The transition section (3) has a second slit (31). The first slit (22) and the second slit (31) intersect at the connection between the tamper-proof section (2) and the transition section (3). The joint section (1), the anti-disassembly section (2), and the transition section (3) all have an adhesive backing layer on the same side in the thickness direction.
2. The tamper-proof flexible circuit board according to claim 1, characterized in that, There are multiple first cuts (22) and second cuts (31), and each first cut (22) and each second cut (31) intersects at the same point.
3. The tamper-proof flexible circuit board according to claim 2, characterized in that, Multiple first cuts (22) and multiple second cuts (31) extend radially from a common intersection point.
4. The tamper-proof flexible circuit board according to claim 2, characterized in that, The length of the first cut (22) is greater than the length of the second cut (31).
5. The tamper-proof flexible circuit board according to claim 2, characterized in that, The first cuts (22) and the second cuts (31) are in one-to-one correspondence, and the first cuts (22) and the corresponding second cuts (31) extend in the same direction.
6. The tamper-proof flexible circuit board according to claim 5, characterized in that, There are two first cuts (22), and the angle between the two first cuts (22) is an acute angle.
7. The tamper-proof flexible circuit board according to claim 1, characterized in that, The joint section (1) has a reinforcing plate.
8. The tamper-proof flexible circuit board according to claim 1, characterized in that, The peel strength of the adhesive layer of the anti-tamper section (2) and the transition section (3) is P1, and the peel strength of the adhesive layer of the joint section (1) is P2, satisfying the relationship: P1 > P2.
9. The tamper-proof flexible circuit board according to any one of claims 1-8, characterized in that, The tamper-proof flexible circuit board further includes a softening and bending section (4), and the transition section (3) is connected to the connector section (1) through the softening and bending section (4).
10. A payment terminal, characterized in that, include: The motherboard, the display screen (20), the housing (30), and the tamper-proof flexible circuit board according to any one of claims 1-9, wherein the motherboard and the display screen (20) are mounted on the housing (30), the connector segment (1) is bonded to the housing (30) by its backing adhesive layer, the tamper-proof segment (2) and the transition segment (3) are bonded to the display screen (20) by their corresponding backing adhesive layers, and the circuit connector (11) is connected to the motherboard.