Safe printed circuit board and electric energy converter

Abstract

The embodiment of the invention provides a safe printed circuit board and an electric energy converter. The printed circuit board comprises at least one layer of copper foil; a fuse is arranged in the printed circuit board and is formed by copper foil; the fuse is connected with the current supply end, and the cross sectional area of the fuse is smaller than that of the copper foils at other positions within the preset range of the current supply end; wherein the current supply end is at least one or more of a power supply input end, a capacitor end and an inductor end; the printed circuit board also includes a plurality of devices that form a plurality of current loops, the fuse being located in a common area where the plurality of current loops have the common area. Therefore, when the current supply end fails or is abnormal, the fuse can be fused to protect the circuit; secondly, the fuse can be designed according to actual needs, and the printed circuit board is simple in process, small in size and low in cost; in addition, the number of fuses can be reduced, and the board area of the printed circuit board is saved.

Description

Technical Field

[0001] This disclosure relates to the field of power electronics technology, and more particularly to a safety printed circuit board and a power converter. Background Technology

[0002] In electronic circuit systems, fuses are typically installed on printed circuit boards (PCBs) to ensure the stability of the system. However, this increases the number of fuses and requires additional installation steps, resulting in more complex PCB manufacturing processes, larger size, and increased costs. Summary of the Invention

[0003] This disclosure provides a safety printed circuit board and a power converter.

[0004] In a first aspect, embodiments of this disclosure provide a safety printed circuit board, the printed circuit board comprising at least one layer of copper foil; the printed circuit board having a fuse formed of the copper foil;

[0005] The fuse is connected to the current supply terminal, and the cross-sectional area of ​​the fuse is smaller than the cross-sectional area of ​​the copper foil at other positions within a preset range of the current supply terminal; wherein the current supply terminal is at least one or more of the following: power input terminal, capacitor terminal, and inductor terminal;

[0006] The printed circuit board also includes multiple devices that form multiple current loops, and the fuse is located in the common area when the multiple current loops have a common area.

[0007] In some embodiments, the fuse includes multiple sub-fuses connected in parallel, the sum of the cross-sectional areas of the multiple sub-fuses being less than or equal to the cross-sectional area of ​​the copper foil connected to the input and output terminals of the fuse;

[0008] When the current flowing through the multiple sub-fuse is greater than the fusing current, the multiple sub-fuse are melted one after another.

[0009] In some embodiments, if the cross-sectional area of ​​at least one of the sub-fuses is not equal to the cross-sectional area of ​​the remaining sub-fuses, the sub-fuse with the smallest cross-sectional area is the first to blow.

[0010] When at least two of the sub-fuses have equal cross-sectional areas, the sub-fuse with the smallest current value carrying the fusing current, determined according to fusing factors, is the first to blow; the fusing factors include at least the manufacturing process of the fuse.

[0011] In some embodiments, the common region includes multiple sets of equipotential networks, and each equipotential network includes multiple equipotential points;

[0012] In each of the equipotential networks, the devices corresponding to the plurality of equipotential points form multiple current paths, and the fuse is located in the current path passing through all the devices in the equipotential network.

[0013] In some embodiments, the plurality of devices include at least two inductors, two capacitors and two switching transistors, wherein one inductor, one capacitor and one switching transistor form an equipotential network of the buck circuit, and another inductor, another capacitor and another switching transistor form another equipotential network of the buck circuit;

[0014] In each of the equipotential networks, the fuse is located in the current path formed by connecting the inductor, the capacitor, and the switch in series.

[0015] In some embodiments, when the device is attached to the surface of the printed circuit board, the fuse is located below the device along a first direction; wherein the first direction is perpendicular to the plane of the printed circuit board.

[0016] In some embodiments, the copper foil has two types, referred to as outer copper foil and inner copper foil, respectively;

[0017] Along the first direction, the outer copper foil is located on the surface of the printed circuit board, and the inner copper foil is located inside the printed circuit board.

[0018] In some embodiments, the printed circuit board further includes a vent.

[0019] When the fuse is located at the inner copper foil, the vent is used to release the gas generated when the fuse melts.

[0020] In some embodiments, the shape of the sub-fuse is at least one or more of the following: straight line, rectangle, S-shape, sawtooth shape, square wave shape.

[0021] In a second aspect, embodiments of this disclosure provide a power converter, the power converter comprising a printed circuit board as described in any one of the first aspects;

[0022] The power converter is used at least to convert DC power into AC power, or AC power into DC power.

[0023] This disclosure provides a safety-type printed circuit board and a power converter. The printed circuit board includes at least one layer of copper foil. A fuse, formed of copper foil, is included in the printed circuit board. The fuse is connected to a current-providing terminal, and the cross-sectional area of ​​the fuse is smaller than the cross-sectional area of ​​the copper foil at other locations within a predetermined range of the current-providing terminal. The current-providing terminal is at least one or more of the following: a power input terminal, a capacitor terminal, and an inductor terminal. The printed circuit board also includes multiple devices forming multiple current loops. When multiple current loops share a common area, the fuse is located in that common area. This allows the fuse to blow to protect the circuit in the event of a fault or abnormality at the current-providing terminal. Secondly, because the fuse is formed of copper foil, the fuse's manufacturing process is consistent with that of the copper foil, allowing the fuse to be designed according to actual needs. This simplifies the printed circuit board's manufacturing process, reduces its size, and lowers its cost. Furthermore, placing the fuse in a common area reduces the number of fuses and saves the printed circuit board's surface area. Attached Figure Description

[0024] Figure 1 A schematic diagram of the structure of a safety-type printed circuit board provided in this embodiment of the present disclosure. Figure 1 ;

[0025] Figure 2 A schematic diagram of the structure of a safety-type printed circuit board provided in this embodiment of the present disclosure. Figure 2 ;

[0026] Figure 3 A schematic diagram of the composition structure of a three-phase circuit provided in an embodiment of this disclosure;

[0027] Figure 4 A schematic diagram of the structure of a safety-type printed circuit board provided in this embodiment of the present disclosure. Figure 3 ;

[0028] Figure 5 A schematic diagram of the composition structure of a step-down circuit provided in this embodiment of the present disclosure. Figure 1 ;

[0029] Figure 6 A schematic diagram of the composition structure of a step-down circuit provided in this embodiment of the present disclosure. Figure 2 ;

[0030] Figure 7 A schematic diagram of the structure of a safety-type printed circuit board provided in this embodiment of the present disclosure. Figure 4 ;

[0031] Figure 8 A schematic diagram of the structure of a safety-type printed circuit board provided in this embodiment of the present disclosure. Figure 5 ;

[0032] Figure 9This is a schematic diagram of the structure of a power converter provided in an embodiment of this disclosure. Detailed Implementation

[0033] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the relevant applications and are not intended to limit the scope of this disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the relevant applications are shown in the accompanying drawings.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to be limiting of this disclosure.

[0035] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0036] It should be noted that the terms "first, second, third" used in the embodiments of this disclosure are merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0037] When a circuit malfunctions or experiences an anomaly, the current continuously increases. This increased current may damage critical components, burn out the circuit, or even cause a fire. If a fuse is correctly placed in the circuit, it will melt and break the current when the current abnormally rises to a certain level, thus protecting the circuit's safe operation. Furthermore, a malfunction or a sudden surge of current can cause components on the PCB board to burn out, rendering the entire PCB unusable and resulting in significant losses.

[0038] Fuse are essential components that protect electronic devices and circuits from overcurrent. Fuses on a PCB are used to protect components and circuits on the PCB from overcurrent caused by short circuits, overloads, and other electrical faults. They are typically mounted on the PCB using surface mount or through-hole technology. However, this increases the number of fuses and requires additional installation steps, leading to a more complex PCB manufacturing process, larger size, and increased cost.

[0039] Based on this, this disclosure provides a safety-type printed circuit board (PCB) comprising at least one layer of copper foil; a fuse formed of copper foil is included in the PCB; the fuse is connected to a current-providing terminal, and the cross-sectional area of ​​the fuse is smaller than the cross-sectional area of ​​the copper foil at other locations within a preset range of the current-providing terminal; wherein the current-providing terminal is at least one or more of the following: a power input terminal, a capacitor terminal, and an inductor terminal; the PCB also includes multiple devices forming multiple current loops, and the fuse is located in the common area when the multiple current loops have a common area. In this way, the fuse can be blown to protect the circuit when a fault or abnormality occurs at the current-providing terminal; secondly, because the fuse is formed of copper foil, the fuse and the copper foil have the same manufacturing process, allowing the fuse to be designed according to actual needs, and simplifying the PCB manufacturing process, reducing its size, and lowering costs; furthermore, placing the fuse in the common area reduces the number of fuses and saves PCB surface area.

[0040] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0041] In one embodiment of this disclosure, see Figure 1 It illustrates a schematic diagram of the structure of a security printed circuit board provided in an embodiment of this disclosure. Figure 1 .like Figure 1 As shown, the printed circuit board 10 includes at least one layer of copper foil; the printed circuit board 10 has a fuse 11, which is formed of copper foil;

[0042] The fuse 11 is connected to the current supply terminal 12. The cross-sectional area of ​​the fuse 11 is smaller than the cross-sectional area of ​​the copper foil at other locations within a preset range of the current supply terminal 12. The current supply terminal 12 is at least one or more of the following: a power input terminal, a capacitor terminal, and an inductor terminal. The printed circuit board 10 may also include multiple devices 13 (not shown in the figure). The multiple devices 13 form multiple current loops. When the multiple current loops have a common area, the fuse 11 is located in the common area.

[0043] It should be noted that the present disclosure provides a safety printed circuit board 10, which has a fuse 11 formed by copper foil on the printed circuit board 10. The fuse 11 can be fabricated by the entire process of the printed circuit board 10, which not only reduces material costs but also reduces manufacturing costs. Compared with the PCB board in the related technology that requires additional fuse installation, the present disclosure can reduce costs and save space.

[0044] Specifically, fuse 11 is connected in series with current supply terminal 12 and load, and current flows through fuse 11 before reaching the load. Since the system's power input terminal provides current, it is used as current supply terminal 12. Also, since the capacitor and inductor terminals release energy in different operating states of the circuit, they can also serve as current supply terminals 12, but this is not specifically limited. In other embodiments, fuse 11 may also be located near other ports that provide energy or current to protect the circuit.

[0045] It should be noted that, in the direction of current flow, the cross-sectional area of ​​fuse 11 is smaller than that of the copper foil at other locations within the preset range of the current supply terminal 12. This results in a higher resistance for fuse 11, causing it to melt when the current flowing through it increases to the fusing current value of fuse 11. The cross-sectional area of ​​fuse 11 can be set according to the required fusing current value, etc. In other words, the difference between the cross-sectional area of ​​fuse 11 and the cross-sectional area of ​​the copper foil at other locations can be set according to actual conditions; the difference can be 20%, 15%, etc., without specific limitations. If the shape of fuse 11 is not uniform, the maximum cross-sectional area of ​​fuse 11 must be smaller than the cross-sectional area of ​​the copper foil at other locations. Figure 1 The shape and cross-sectional area of ​​the fuse 11 in the figure are merely examples and are not specifically limited thereto.

[0046] It should also be noted that fuse 11 should be placed as close as possible to the current supply terminal 12 to ensure that its protection circuit is protected from overcurrent and other conditions. Furthermore, the size of a preset range can be set according to the range of devices that need protection in the circuit, placing the protected devices within the preset range; alternatively, the size of the preset range can be set according to the position of another current supply terminal 12 close to this current supply terminal 12. The cross-sectional area of ​​the copper foil between the two fuses 11 corresponding to the two current supply terminals 12 is greater than the cross-sectional area of ​​fuse 11. The size of the preset range can be set according to the actual situation and is not specifically limited. Understandably, the cross-sectional area of ​​fuse 11 is less than or equal to the cross-sectional area of ​​the copper foil connected to the input and output terminals of fuse 11.

[0047] It should also be noted that the device 13 forming the current loop may include capacitors, inductors, resistors, switching transistors, etc., but there are no specific limitations on this.

[0048] In this embodiment, the system power supply (i.e., the power input terminal) may not be able to cover all current loops. According to the current loops, the position of the fuse 11 can be set in the common area covering multiple current loops, thereby reducing the number of fuses 11 and saving the board area of ​​the PCB board.

[0049] This disclosure provides a safety printed circuit board 10. Near the current supply terminal 12, the copper foil at the point where melting is required is designed as a fuse 11 with a smaller cross-sectional area (i.e., smaller than the cross-sectional area of ​​the copper foil at other locations). This allows the fuse to only meet the requirements of normal current and become a weak point for large current (i.e., its current value is greater than the melting current value of the corresponding fuse 11) in the event of a fault. When a large current flows through the circuit, the fuse 11 melts to protect the circuit. In addition, placing the fuses 11 in a common area can reduce the number of fuses 11 and save the PCB board area.

[0050] In some embodiments, such as Figure 2 As shown, the fuse 11 may include multiple sub-fuse 111 connected in parallel, and the sum of the cross-sectional areas of the multiple sub-fuse 111 is less than or equal to the cross-sectional area of ​​the copper foil connected to the input and output terminals of the fuse 11.

[0051] When the current flowing through the multiple sub-fuse 111 is greater than the fusing current, the multiple sub-fuse 111 will be melted step by step.

[0052] Here, the sum of the cross-sectional areas of the multiple sub-fuse 111 is equal to the cross-sectional area of ​​a single fuse 11.

[0053] It should be noted that the fusing speed of the fuse (fuse 11 and / or sub-fuse 111) is related to the magnitude of the current it carries. When the current in the circuit is too high, the fuse will heat up and automatically melt, cutting off the circuit and thus protecting it. Specifically, the fusing speed of the fuse increases with the increase of current because the melting time decreases as the overcurrent increases.

[0054] It should also be noted that the cross-sectional area of ​​a single sub-fuse 111 is smaller than that of fuse 11, so it can carry a smaller current. In other words, the fusing current of a single sub-fuse 111 is different from the fusing current of fuse 11 (hereinafter referred to as the fusing current value). The fusing current value of a single sub-fuse 111 is smaller than that of fuse 11. In this embodiment, the current value flowing through multiple sub-fuse 111 being greater than the fusing current value means that the current value flowing through multiple sub-fuse 111 is greater than the fusing current value of fuse 11, and of course, also greater than the fusing current value of each sub-fuse 111. For example, if the fusing current value of a single fuse 11 is 10A (amperes), two sub-fuse 111 with fusing current values ​​of 5A each can be connected in parallel to replace it.

[0055] When a large current flows through the circuit, one sub-fuse 111 (also known as the first-stage sub-fuse 111) will melt first. The sum of the cross-sectional areas of the remaining sub-fuse 111 will decrease, and the current that can be carried will decrease. The current in the circuit will pass through the remaining sub-fuse 111, triggering the remaining sub-fuse 111 to melt quickly. This will cause multiple sub-fuse 111 to melt in stages, and the total time for multiple sub-fuse 111 to melt is less than the time for a single fuse 11 to melt, thus achieving the purpose of rapid melting and cutting off the circuit.

[0056] In this embodiment, the copper foil at the point where melting is required is designed as multiple sub-fuse 111 connected in parallel. The combined current carrying capacity of the multiple sub-fuse 111 only needs to meet the requirements of normal current. When a fault occurs and a large current flows through the circuit, one sub-fuse 111 will inevitably melt first. If one sub-fuse 111 melts first, the sum of the cross-sectional areas of the remaining sub-fuse 111 decreases, and the current value that can be passed becomes smaller, which will trigger the remaining sub-fuse 111 to burn out quickly, achieving the purpose of rapid melting and cutting off the circuit.

[0057] It should be noted that the cross-sectional areas of the multiple sub-fuses 111 can be all equal, partially equal, or all unequal; the specific configuration can be determined based on the actual situation, and no specific limitation is imposed. For example, Figure 2 The fuse 11 in the middle includes three sub-fuse 111 with equal cross-sectional areas.

[0058] Furthermore, in some embodiments, if the cross-sectional area of ​​at least one sub-fuse 111 is not equal to the cross-sectional area of ​​the remaining sub-fuse 111, the sub-fuse 111 with the smallest cross-sectional area is the first to be blown.

[0059] When at least two sub-fuse 111 have equal cross-sectional areas, the sub-fuse 111 with the smallest carrying fusing current value determined according to the fusing factors is the first to be blown; the fusing factors include at least the manufacturing process of the fuse.

[0060] It should be noted that if there are three sub-fuses 111-1, 111-2, and 111-3, and the cross-sectional area of ​​sub-fuses 111-1 is smaller than that of sub-fuses 111-2, and the cross-sectional area of ​​sub-fuses 111-2 is smaller than that of sub-fuses 111-3, when the current flowing through the multiple sub-fuses 111 exceeds the fusing current, sub-fuses 111-1 will be the first to blow because it has the smallest cross-sectional area. If there are three sub-fuses 111-1, 111-2, and 111-3, and the cross-sectional area of ​​sub-fuses 111-1 is larger than that of sub-fuses 111-2, and the cross-sectional area of ​​sub-fuses 111-2 is equal to that of sub-fuses 111-3, then the sub-fuses 111 with the smallest fusing current among sub-fuses 111-2 and 111-3 will be the first to blow. If there are three sub-fuse 111-1, 111-2 and 111-3, when the cross-sectional areas of the sub-fuse 111-1, 111-2 and 111-3 are all equal, the sub-fuse 111, which carries the smallest fusing current value among the three sub-fuse 1s, will be the first to blow.

[0061] It should also be noted that even if the two sub-fuse 111s have the same cross-sectional area in the design, due to factors such as the actual manufacturing process, one sub-fuse 111 will inevitably have a weaker current-carrying capacity and the smallest fusing current value, and will be the first to melt. The manufacturing process is also a crucial factor affecting the fuse's fusing current value. The manufacturing process must ensure the consistency and reliability of the fuses to guarantee their proper functioning during use; poor manufacturing processes may lead to unstable fuse performance, thus affecting their fusing current value.

[0062] In summary, when multiple sub-fuse 111s are designed with equal cross-sectional areas, one sub-fuse 111 will likely blow first, depending on the fusing factors. Alternatively, the multiple sub-fuse 111s can be designed with unequal cross-sectional areas, in which case the sub-fuse 111 with the smallest cross-sectional area will blow first. When considering the fusing speed, the influence of cross-sectional area should be given priority, followed by the influence of manufacturing processes and other fusing factors.

[0063] See Figure 3 This illustrates a schematic diagram of the composition structure of a three-phase circuit provided in an embodiment of this disclosure. Figure 3As shown, this is a three-phase filter circuit using filter capacitors. The three phases are A-phase, B-phase, and C-phase. Each phase includes a positive half-cycle circuit and a negative half-cycle circuit. Capacitor C1, resistors R1, R2, and R3 form the positive half-cycle circuit of phase A; capacitor C3, resistors R4, R5, and R6 form the negative half-cycle circuit of phase A; capacitor C5, resistors R13, R14, and R15 form the positive half-cycle circuit of phase B; capacitor C7, resistors R16, R17, and R18 form the negative half-cycle circuit of phase B; capacitor C9, resistors R25, R26, and R27 form the positive half-cycle circuit of phase C; and capacitor C11, resistors R28, R29, and R30 form the negative half-cycle circuit of phase C. The specific connection relationship is as follows. Figure 3 As shown.

[0064] based on Figure 3 For a schematic diagram of the corresponding printed circuit board 10, please refer to the circuit diagram shown. Figure 4 .like Figure 4 As shown, region 21 represents phase A, region 22 represents phase B, and region 23 represents phase C. Within region 21, region 211 represents the positive half-cycle circuit of phase A, and the remaining regions represent the negative half-cycle circuit of phase A. In region 211, fuse f1 represents the fuse near the power input terminal, and fuses f2 and f3 represent fuses near the capacitor terminals. For understanding the location of the fuses in the negative half-cycle circuit of phase A, please refer to the positive half-cycle circuit of phase A. Similarly, for understanding the structure of the positive and negative half-cycle circuits and the fuse locations in phases B and C, please refer to phase A; these details will not be repeated here. In summary, fuses are installed at both the power input terminal and the capacitor terminal of each phase.

[0065] It should be noted that a common area on a PCB board may correspond to an equipotential point in the circuit schematic. In some embodiments, the common area includes multiple sets of equipotential networks, and each equipotential network includes multiple equipotential points;

[0066] In each equipotential network, multiple devices 13 corresponding to multiple equipotential points form multiple current paths, and the fuse 11 is located in the current path passing through all devices in the equipotential network.

[0067] It should be noted that in an equipotential network, according to the PCB design method, the position of fuse 11 can be set at a circuit node that can cover multiple current loops, converting parallel to serial, so that the current path where fuse 11 is located is as much as possible a necessary path for the current.

[0068] like Figure 5As shown, taking a buck circuit as an example, node a near inductor L1, node b near capacitor C1, and node c near switch SCR1 are at the same potential. Similarly, node d near inductor L2, node e near capacitor C2, and node f near switch SCR2 are at the same potential. The buck circuit is a DC-DC (Direct Current) converter, and its output voltage is lower than its input voltage.

[0069] It should be noted that the step-down circuit has different operating states, such as inductor energy storage state, inductor freewheeling state, and electrolytic capacitor as load (battery BAT) discharge state. In different operating states, the current loops formed by the enabling devices are different, so fuse 11 should be placed in the common area of ​​multiple current loops.

[0070] In some embodiments, for Figure 5 The step-down circuit shown is simplified, as follows: Figure 6 As shown, the plurality of devices 13 include at least two inductors (represented by reference numerals 131 and 132), two capacitors (represented by reference numerals 133 and 134), and two switching transistors (represented by reference numerals 135 and 136). One inductor (e.g., 131), one capacitor (e.g., 133), and one switching transistor (e.g., 135) form an equipotential network for the buck converter, and another inductor (e.g., 132), another capacitor (e.g., 134), and another switching transistor (e.g., 136) form another equipotential network for the buck converter.

[0071] In each equipotential network, fuse 11 is located in the current path formed by connecting the inductor, capacitor and switching transistor in series.

[0072] It should be noted that the switching transistor can be a silicon controlled rectifier (SCR), also known as a thyristor, which is a semiconductor switching device. It should also be noted that... Figure 6 Inductor 131 in Figure 5 Similarly, in the example L1, inductor 132 is L2, capacitor 133 is C1, capacitor 134 is C2, switching transistor 135 is SCR1, and switching transistor 136 is SCR2.

[0073] based on Figure 6 For the circuit diagram shown, please refer to the structural schematic diagram of the corresponding printed circuit board 10. Figure 7 . Figure 7 (a) in the diagram corresponds to the layout of the equipotential network formed by inductor 131, capacitor 133, and switch 135. Figure 7 (b) in the diagram corresponds to the layout of the equipotential network formed by inductor 132, capacitor 134, and switch 136.

[0074] like Figure 7 As shown in (a), inductor 131 (L1) is directly connected to switching transistor 135 (SCR1), bypassing capacitor 133 (C1). Fuse 11 (not shown) near capacitor 133 is not placed in this current path; the three devices are similar to being connected in parallel. Figure 7 As shown in (b), inductor 132 (L2) is connected to capacitor 134 (C2) and then to switching transistor 136 (SCR2). These three devices are essentially connected in series. Placing fuse 11 in the current path formed by the series connection of the inductor, capacitor, and switching transistor protects all three devices in that current path. Compared to... Figure 7 (a) in the middle, Figure 7 The layout method in (b) can save fuse 11.

[0075] In some embodiments, when the device 13 is attached to the surface of the printed circuit board 10, the fuse 11 is located below the device 13 along a first direction; wherein the first direction is perpendicular to the plane on which the printed circuit board 10 is located.

[0076] Specifically, the bottom surface of device 13 is bonded to the top surface of printed circuit board 10. Device 13 bonded to the surface of printed circuit board 10 may include capacitors, inductors, or surface mount devices, but is not specifically limited thereto. A surface mount device is an electronic component used for surface mounting on a PCB board, allowing for a more compact layout on the printed circuit board. Surface mount devices typically come in different sizes and shapes, including surface mount resistors, surface mount capacitors, and surface mount inductors.

[0077] It should also be noted that when fuse 11 is placed below device 13 along the first direction, because device 13 presses against printed circuit board 10, the fuse 11 will burn and generate sparks after it melts. The small gap and limited air between device 13 and printed circuit board 10 will extinguish fuse 11. In other words, because there is no air after fuse 11 melts, it is quickly extinguished, preventing damage to other devices due to fire. Furthermore, placing fuse 11 under device 13, which is attached to the surface of printed circuit board 10, not only extinguishes the fire but also, because the heat cannot dissipate, heats fuse 11 located below device 13 more quickly, accelerating its melting.

[0078] In some embodiments, the copper foil has two types, referred to as outer copper foil and inner copper foil, respectively;

[0079] Along the first direction, the outer copper foil is located on the surface of the printed circuit board 10, and the inner copper foil is located inside the printed circuit board 10.

[0080] It should be noted that the outer copper foil is a layer of metal foil on the surface of the printed circuit board 10, used to connect various devices; the inner copper foil is a layer of metal foil located between the inner signal layers, used for circuit connection and transmission. The outer copper foil may include the top copper foil and / or the bottom copper foil, while the inner copper foil refers to the copper foil excluding the top and bottom copper foils.

[0081] In some embodiments, such as Figure 8 As shown, the printed circuit board 10 may also include a vent 14 (only one numeral 14 is shown in the figure); when the fuse 11 is located at the inner copper foil, the vent 14 is used to release the gas generated when the fuse 11 is melted.

[0082] In this embodiment, when the circuit that actually needs protection cannot be traced on the surface of the printed circuit board 10, it can only be protected by the internal fuse 11. Therefore, the fuse 11 needs to be designed in the inner copper foil layer. When the fuse 11 is designed in the inner copper foil layer, a vent 14 needs to be provided in the printed circuit board 10 to release gas when the fuse 11 melts due to a circuit failure, preventing excessive pressure inside the printed circuit board 10 from causing other problems.

[0083] It should be noted that the vent 14 can be a vent hole or a vent groove, and the vent hole can be a through hole, but there is no specific limitation on either, as long as the vent 14 can release gas. For example, Figure 8 It includes four vents 14, which are located around the fuse 11, but the number and location of the vents 14 are not specifically limited.

[0084] In some embodiments, the shape of the sub-fuse 111 is at least one or more of the following: straight, rectangular, S-shaped, sawtooth, or square wave.

[0085] It should be noted that the shape of fuse 11 is at least one or more of the following: straight, rectangular, S-shaped, sawtooth, or square wave.

[0086] It should also be noted that for multiple sub-fuse 111 connected in parallel, the shapes of each sub-fuse 111 can be the same or different, and can be set according to the actual situation, without specific limitations.

[0087] In summary, this disclosure provides a safety-type printed circuit board 10, which includes a board-level fuse (i.e., fuse 11). First, the fuse 11 can melt and break under conditions such as short circuits and high current. Second, the melting point of the fuse 11 can be designed as needed. Third, placing the fuse 11 under capacitors or other devices 13 attached to the printed circuit board 10 allows for rapid extinguishing of the fuse 11 after it melts due to the lack of air, preventing damage to other devices from fire. Furthermore, because the heat cannot dissipate, it can more quickly heat the fuse 11 below, accelerating its melting. Fourth, the fuse 11 uses the same manufacturing process as other copper foils in the printed circuit board 10, simplifying the manufacturing process and reducing costs. Finally, the fuse 11 can be flexibly positioned, allowing it to be placed on an inner layer of the printed circuit board 10.

[0088] In another embodiment of this disclosure, see Figure 9 This illustration shows a schematic diagram of the structure of a power converter provided in an embodiment of this disclosure. Figure 9 As shown, the power converter 30 includes the aforementioned printed circuit board 10;

[0089] The power converter 30 is used at least to convert DC power into AC power, or AC power into DC power.

[0090] It should be noted that the power converter 30 may include an inverter, a converter, and a rectifier. The inverter can convert DC power into AC power; the rectifier can convert AC power into DC power; and the converter can convert fixed-frequency AC power into adjustable-frequency AC power, or it can convert DC power into AC power.

[0091] The power converter 30, since it includes the aforementioned printed circuit board 10, has at least the same advantages as the printed circuit board 10. It can blow the fuse 11 to protect the circuit when a fault or abnormality occurs at the current supply terminal 12. Secondly, since the fuse 11 is formed of copper foil, the fuse 11 and the copper foil have the same process, which allows the fuse 11 to be designed according to actual needs, and makes the process of the printed circuit board 10 simple, smaller in size and lower in cost. In addition, placing the fuse 11 in a common area can reduce the number of fuses 11 and save the board area of ​​the printed circuit board 10.

[0092] For details not disclosed in the embodiments of this disclosure, please refer to the description of the foregoing embodiments for understanding.

[0093] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure.

[0094] It should be noted that, in this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0095] The sequence numbers of the embodiments disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0096] The methods disclosed in the several method embodiments provided in this disclosure can be arbitrarily combined without conflict to obtain new method embodiments.

[0097] The features disclosed in the several product embodiments provided in this disclosure can be combined arbitrarily without conflict to obtain new product embodiments.

[0098] The features disclosed in the several method or device embodiments provided in this disclosure can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0099] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A security printed circuit board, characterized in that, The printed circuit board includes at least one layer of copper foil; the printed circuit board has a fuse formed of the copper foil; The fuse is connected to the current supply terminal, and the cross-sectional area of ​​the fuse is smaller than the cross-sectional area of ​​the copper foil at other positions within a preset range of the current supply terminal; wherein the current supply terminal is at least one or more of the following: power input terminal, capacitor terminal, and inductor terminal; The printed circuit board also includes multiple devices that form multiple current loops, and the fuse is located in the common area when the multiple current loops have a common area.

2. The printed circuit board according to claim 1, characterized in that, The fuse includes multiple sub-fuses connected in parallel, and the sum of the cross-sectional areas of the multiple sub-fuses is less than or equal to the cross-sectional area of ​​the copper foil connected to the input and output terminals of the fuse. When the current flowing through the multiple sub-fuse is greater than the fusing current, the multiple sub-fuse are melted one after another.

3. The printed circuit board according to claim 2, characterized in that, If the cross-sectional area of ​​at least one of the sub-fuses is not equal to the cross-sectional area of ​​the remaining sub-fuses, the sub-fuse with the smallest cross-sectional area will be the first to blow. When at least two of the sub-fuses have equal cross-sectional areas, the sub-fuse with the smallest current value carrying the fusing current, determined according to fusing factors, is the first to blow; the fusing factors include at least the manufacturing process of the fuse.

4. The printed circuit board according to claim 1, characterized in that, The common region includes multiple sets of equipotential networks, and each equipotential network includes multiple equipotential points; In each of the equipotential networks, the devices corresponding to the plurality of equipotential points form multiple current paths, and the fuse is located in the current path passing through all the devices in the equipotential network.

5. The printed circuit board according to claim 4, characterized in that, The plurality of devices include at least two inductors, two capacitors and two switching transistors, one inductor, one capacitor and one switching transistor form an equipotential network of the buck circuit, and another inductor, another capacitor and another switching transistor form another equipotential network of the buck circuit; In each of the equipotential networks, the fuse is located in the current path formed by connecting the inductor, the capacitor, and the switch in series.

6. The printed circuit board according to claim 1, characterized in that, When the device is attached to the surface of the printed circuit board, the fuse is located below the device along a first direction; wherein the first direction is perpendicular to the plane of the printed circuit board.

7. The printed circuit board according to claim 1, characterized in that, The copper foil has two types, referred to as outer copper foil and inner copper foil, respectively; Along the first direction, the outer copper foil is located on the surface of the printed circuit board, and the inner copper foil is located inside the printed circuit board.

8. The printed circuit board according to claim 7, characterized in that, The printed circuit board also includes a vent. When the fuse is located at the inner copper foil, the vent is used to release the gas generated when the fuse melts.

9. The printed circuit board according to claim 2, characterized in that, The shape of the sub-fuse is at least one or more of the following: straight, rectangular, S-shaped, sawtooth, or square wave.

10. A power converter, characterized in that, The power converter includes a printed circuit board as described in any one of claims 1 to 9; The power converter is used at least to convert DC power into AC power, or AC power into DC power.

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