WO2022229008A1

WO2022229008A1 - Conductor trace fuse

Info

Publication number: WO2022229008A1
Application number: PCT/EP2022/060626
Authority: WO
Inventors: Sascha STEINER
Original assignee: Tridonic Gmbh & Co Kg
Priority date: 2021-04-29
Filing date: 2022-04-21
Publication date: 2022-11-03
Also published as: DE102021111041A1

Abstract

Conductor trace fuse for an electrical device, wherein the conductor trace fuse has a first connection section and a second connection section, and a conductor trace section arranged between the first connection section and the second connection section. Conductor trace section is characterized in that the conductor trace section and/or the first and the second connection section are constructed as a conductor trace that is flexible at least in subsections. Further shown is an arrangement of a circuit board and a corresponding conductor trace fuse, and an electrical device with such an arrangement.

Description

CONDUCTOR TRACE FUSE Description :

[0001 ] The invention relates to a conductor trace fuse for an electrical circuit. Also included are a circuit board comprising an electrical circuit and a conductor trace fuse of this type, and an electrical device comprising a circuit board with the electrical circuit and the conductor trace fuse.

[0002] A conductor trace fuse arranged on a circuit board fulfills the task of quickly and reliably interrupting a connection, in particular the connection of the circuit to a voltage supply when an abnormal operating state of the circuit arranged on the circuit board, and in particular a short- circuit, occurs. In this case, the conductor trace fuse prevents the short-circuit from propagating on the printed circuit board and causing damage beyond the melting of the conductor trace fuse. Timely blowing of the conductor trace fuse can also prevent a mains safety switch from being triggered by the short-circuit on the printed circuit board.

[0003] The function of the conductor trace fuse is fulfilled by a conductor trace section which is arranged on the circuit board and, in comparison to the other conductor traces of the circuit on the circuit board, comprises a conductor cross-section that is reduced with regard to the current flowing through this section. This conductor trace section with reduced cross-section ("blowing region") melts in as controlled a manner as possible when a short-circuit occurs as a result of the short-circuit current, and thus interrupts the current circuit. In this respect, the conductor trace fuse behaves in a comparable manner to a conventional fuse. In particular in the event that an electrical current that clearly exceeds a prespecified rated current of the conductor trace section is applied to this conductor trace section with reduced cross-section, the material of the conductor trace section in the blowing region evaporates or melts.

[0004] Melting and evaporation of the conductor trace fuse within the context of a (primary) short-circuit generates a plasma and an arc, either of which is suitable for short-circuiting a further, spatially adjacent, low-impedance contact pair connected to the mains voltage, the plasma or the arc thus continuing to burn in an uncontrolled manner. In this way, an indirect (secondary) short-circuit is triggered which, under certain circumstances, generates significantly more conductive plasma due to clearly increased quantities of metal than the primary short- circuit might, and can thus also cause significantly greater damage than the primary short-circuit. Under certain circumstances, this process can continue until the mains circuit-breaker is tripped. This applies in particular in the mains input region of a circuit, the lower the resistance of a mains input filter and thus the higher a nominal power consumption of an electrical device will be with this circuit.

[0005] Conductor trace fuses are therefore often arranged in the region of mains input terminals for the mains voltage supply of an electrical device. It is therefore also to be ensured here that the emitted gases and particles cannot escape from the housing of the electrical device via feedthroughs for the mains voltage connections in the event that the conductor trace fuse is tripped. Electrical devices to which this applies are, for example, operating devices for illuminants.

[0006] DE 10 2004 0440683 A1 discloses a partition wall which is arranged on a circuit board and, given a short-circuit and the melting of the conductor trace fuse that is thereby triggered, prevents the plasma thereby arising from passing over to an adjacent conductor trace. The partition wall is designed such that the partition wall forms at least one deflection surface on a side of the partition wall facing the conductor trace fuse, at which deflection surface the plasma is directed away from circuit regions to be protected and the conductor traces thereof.

[0007] However, the arrangement of the partition wall requires an additional surface on the circuit board and the partition wall represents an additional component. This solution thus requires additional effort and poses an obstacle to a desired miniaturization of electrical circuits.

[0008] DE 3723832 A1 discloses conductor trace fuses which are designed as a fuse with a correspondingly reduced conductor trace section in the blowing region and in which the conductor trace section with the reduced cross-section is covered with a spark-extinguishing medium. It is further proposed to arrange a recess in the conductor trace section which is designed, for example, as a hole and enables a controlled discharge of the gas/plasma forming when the conductor trace section melts.

[0009] Adisadvantage of the proposed solutions is the additional and complicated attachment of a cover layer with the spark-extinguishing medium, and the additional manufacturing step of producing a recess in the conductor trace section. In addition, a cover layer can bring about a heat build-up which has an unfavorable effect on the interruption of the short-circuit current.

[0010] Proceeding from the disadvantages of the known prior art, the object is to provide a conductor trace fuse for circuit boards that is cost-effective to produce and, in the event of tripping, limits a burning region and prevents the occurrence or continuation of an arc. [001 1 ] In a first aspect, the object is achieved by a conductor trace fuse having the features of Claim 1. An arrangement according to a second aspect and an electrical device according to a third aspect show further advantageous developments of the invention.

[0012] Advantageous embodiments are described in the dependent claims.

[0013] Aconductor trace fuse for an electrical device according to the first aspect comprises a first and a second connection section, and a conductor trace section which is arranged between the first and the second connection sections and is designed as a blowing region. The conductor trace fuse is characterized in that the conductor trace section and/ or at least the first or the second connection section is constructed as a conductor trace that is flexible at least in subsections.

[0014] The design of the conductor trace fuse according to the first aspect increases the degrees of freedom in the design, in particular the spatial design and arrangement of structural elements of electrical devices.

[0015] The use of flexible conductor traces or conductor trace sections enables the arrangement of the conductor trace fuse with more degrees of freedom in space than is possible with rigid conductor trace sections on rigid circuit boards. The conductor trace fuse can be arranged at a distance from the circuit board, whereby improved heat dissipation can be achieved during the blowing of the conductor trace section functioning as blowing region.

[0016] An increased packing density within a housing of an electrical device (electronic device) is made possible since a third spatial dimension perpendicular to a substantially planar and therefore two-dimensional arrangement of the circuit structures on a circuit board can be used easily.

[0017] The invention provides a conductor trace fuse for a circuit board that is cost-effective to produce and, in the event of a fault, enables a safe and reliable disconnection of the power supply to the circuit board. The operational safety of the circuit board is thus improved.

[0018] Furthermore, a conductor trace fuse makes it possible to replace the otherwise frequently used fine fuse for protecting electrical or electronic devices, whereby the fine-fuse holder for the electrical contacting and mechanical positioning of the fine fuse can be dispensed with. [0019] The conductor trace fuse according to a preferred embodiment is characterized in that the first and the second connection sections in each case comprise a first rigid subsection, and each of the first rigid subsections comprises a fastening region for electrical and mechanical connection to a circuit board.

[0020] In particular, the conductor trace section and/ or the first and second connection sections can in each case be arranged on a side of the first rigid subsection that faces away from and is arranged at a distance from the fastening region.

[0021 ] The conductor trace fuse of one embodiment arranges the first rigid subsection of the first connection section and the first rigid subsection of the second connection section substantially parallel to one another.

[0022] This arrangement makes it possible to arrange the blowing region at a defined and reproducible distance from other elements, for example other circuit structures, components, or housing openings.

[0023] In one embodiment of the conductor trace fuse, the conductor trace section is constructed as a flexible conductor trace, which connects the rigid first and the second connection section to one another.

[0024] The conductor trace fuse can thus be arranged in a simple manner at an offset from the circuit board, for example in a housing recess of an assembly housing.

[0025] The second aspect relates to an arrangement comprising a circuit board and a conductor trace fuse according to one of the embodiments of the conductor trace fuse of the first aspect.

[0026] It is advantageous if the conductor trace section is arranged at a distance from the circuit board.

[0027] The arrangement can arrange the conductor trace fuse at a distance above or below a plane of the circuit board.

[0028] A particle, gas and/ or plasma stream emanating from the blowing region thus only impinges in an expanded manner on the circuit board and in critical circuit regions and components arranged thereon. This is the case since the particle, gas and/or plasma stream can spread unhindered in parts from the breakthrough region in the space around the circuit board, and a density of the particle, gas and/ or plasma stream in the propagation front corresponding to the propagation correspondingly decreases non-linearly with distance.

[0029] The arrangement of conduct board and conductor trace fuse can arrange the conduct trace fuse in an orientation differing from main extension directions of the circuit board.

[0030] Accordingly, an operational safety of the circuit board is increased by means of a simple- to-produce and reliably triggering conductor trace fuse, which significantly simplifies the design process by incorporating all three spatial directions and results in design solutions of improved quality.

[0031] The third aspect relates to an electrical device which comprises at least one arrangement according to the second aspect comprising a circuit board and a conductor trace fuse according to the first aspect.

[0032] The electrical device (electrical device) can in particular be an operating device (ballast, driver) for illuminants.

[0033] The electrical device can have a housing and mains input terminals arranged on the housing, wherein the conductor trace fuse is arranged at a distance from the mains input terminals within the housing.

[0034] This reduces or completely prevents a particle, gas and/ or plasma stream from escaping through housing openings of mains supply lines of the electrical device.

[0035] Advantageous exemplary embodiments of the invention are shown in the figures and are explained in more detail using the following description. The following are shown:

Figure 1 a schematic view of a first embodiment of a conductor trace fuse according to the invention,

Figure 2 a schematic view of a second embodiment of a conductor trace fuse according to the invention, and

Figure 3 a side view of a circuit board with a conductor trace fuse according to the invention arranged in an electrical device. [0036] In different figures, identical reference signs designate identical or corresponding elements. In the following explanation of the figures, insofar as considered unnecessary, a repeated description of the same reference signs in different figures is dispensed with.

[0037] Conductor trace fuses are basically well-known. A conductor trace fuse is a conductor arrangement or conductor section which is located on a circuit board and, in the event of a short- circuit or another current overload, disconnects, for example, an electrical connection to the voltage supply for the circuit regions downstream of the conductor trace fuse on the circuit board. The conductor trace fuse can be designed as a conductor trace section on the circuit board, which conductor trace section has a reduced conductor trace cross-section in relation to other conductor traces of the circuit board. If a current flow through the conductor trace section exceeds a prespecified limit value, which is defined by the cross-section of the conductor trace section, the conductor trace section should melt substantially reliably in as controlled a manner as possible. A further current flow via the conductor trace section is thus prevented. A current circuit via the conductor trace section is thus interrupted by the conductor trace fuse tripping in the event of a short-circuit.

[0038] Figure 1 shows a schematic view of a first embodiment of a conductor trace fuse 1 according to the invention. The conductor trace fuse 1 is mounted on a circuit board 10 and shown in partial cross-section.

[0039] The circuit board 10 is a single-layer circuit board 10 with conductor traces 13 and surface- mounted electrical components 11 and is only drawn with a partial detail. The circuit board 10 shown, which is populated on one side, is merely an example, and a multi-layer circuit board 10 or a circuit board 10 equipped on both sides may also be used. The components 11 can be mounted and contacted in a surface-mounted manner (SMD) or by means of a via on the circuit board 10. The conductor traces and components 13 realize an electrical circuit.

[0040] The conductor trace fuse 1 comprises a conductor trace section 3 which, at its two ends facing away from one another, is connected in each case to a connection section 2 A, 2B of the conductor trace fuse 1.

[0041] The conductor trace section 3 comprises or is formed completely by a conductor trace applied to a flexible base material. The conductor trace is dimensioned such that, in the event of an electrical current flow through the conductor trace which corresponds to a rated current of the conductor trace fuse or of the conductor trace section 3, the conductor trace melts in as controlled a manner as possible and prevents a further current flow via the conductor trace section 3. The conductor trace section 3 thus represents a breakthrough region for the conductor trace fuse 1.

[0042] In the exemplary embodiment shown in Figure 1, the first connection section 2A and the second connection section 2B of the conductor trace fuse 1 each comprise a first connection subsection 3 A, 3B and a second connection subsection 4A and 4B.

[0043] The first connection subsection 3 A, 3B is realized, corresponding to the conductor trace section 3, as a conductor trace applied to the flexible base material.

[0044] The second connection subsection 4 A, 4B is realized in Figure 1 as a conductor structure applied in a solid (rigid) base material. The conductor structure of the second connection subsections 4 A, 4B is in each case electrically connected to the first connection subsections 3 A, 3B at a first end.

[0045] A contact 5 A, 5B is arranged in each case at a second end of the second connection subsection 4 A, 4B facing away from the conductor trace section 3. The contacts 5 A, 5B are each electrically conductively connected to the conductor structure of the second connection subsections 4 A, 4B.

[0046] The conductor trace section 3 can thus be electrically contacted via the contacts 5 A, 5B. The contacts 5 A, 5B enable an electrically conductive connection of conductor traces 13 (feeds) conductor trace section 3 to be produced.

[0047] The conductor trace fuse 1 shown in Figure 1 makes it possible to arrange the conductor trace section 3 spatially at a distance D from a surface of the circuit board 10. In the case shown, the magnitude of the distance D is defined in space unambiguously in relation to the circuit board 10 by the length of the second connection subsections 4 A, 4B, which have a solid base material.

[0048] The conductor trace fuse 1, in particular the conductor trace section 1 and the first connection section 2 A and the second connection section 2B can be manufactured in one piece or can be produced individually in several parts and subsequently assembled. The conductor trace fuse 1 manufactured in several parts can be assembled prior to being mounted on the circuit board 10 or can be assembled with its parts individually on the circuit board 10. [0049] The flexible base material can be a material common for flexible layers (flex layers) of a circuit board 10. A flexible layer of a circuit board 10 may be manufactured of polyimide, for example.

[0050] The first connection subsection 3 A, 3B fulfills a function comparable to an FPC connector. An FPC connector is a flexible circuit board (flexible printed circuit; abbreviated: FPC) which serves to connect electrical assemblies with at least one degree of freedom for the connection. FPC connectors can be printed circuits whose conductor traces 13 are constructed on a flexible plastic carrier, in particular made of polyimide, but for example also Mylar, nylon, or polyester film. Copper or also silver can be used as conductor material. In particular contact regions, such as the contacts 5 A, 5B, can be gold-plated in order to satisfy increased requirements for electrical conductivity. The carrier material has to satisfy fire protection regulations.

[0051] Polyimides are plastics which are often non-meltable and chemically resistant, even with respect to many solvents. In the present case, polyimides are advantageous in the form of semi transparent films due to their heat resistance, low outgassing, radiation resistance, and insulating properties. Polyimides withstand high permanent temperatures, for example up to 230°C, and brief temperature loads up to 400°C.

[0052] Flexible connections for permanent bending stress can also be designed as a polyimide film circuit board.

[0053] Rigid-flexible circuit boards comprise a combination of flexible and rigid layers. After pressing of the layers, a rigid -flexible circuit board is obtained. The structure of rigid-flexible circuit boards can have polyimide films on or between ordinary FR4 layers which, after milling (depth milling), result in regions of different thickness and flexibility.

[0054] Semi-flexible circuit boards are required for non-permanently flexible regions in the circuit board, e.g., in order to enable assembly in limited space. There is the approach of tapering the layer stack of a circuit board constructed from a plurality of prepregs, by milling except for a few layers or tapering pre-punched prepregs (pre-impregnated glass fabric impregnated with resin, pre-dried but not yet cured) with recessed regions in subregions. The tapered region can be provided with a permanently flexible lacquer layer. A small number of bending processes for the semi-flexible circuit board can thus be carried out. [0055] If the quantity of existing ionizable material is reduced on both sides of a breakthrough region of the conductor trace fuse 1, this will promote an extinguishing of an arc forming in the event of an electrical current exceeding the rated current via the conductor trace fuse 1 against. The arrangement of the conductor trace section 3, which substantially defines the breakthrough region in space, at a distance D from the circuit board 10 is thus particularly advantageous.

[0056] It may be expedient to provide a good heat-conducting coating material for the conductor trace section 3 in order to control the formation of the arc and to influence the burning behavior of the blowing region. The coating material brings about cooling and additionally has an arc extinguishing effect. However, a further advantage is that the conductor trace section 3 is arranged at an offset from the heat sources, i.e., components 11 and circuit board 10, and thus thermally favorably within an electrical device.

[0057] It is thus ensured that the arc ignites in a controlled manner. The formation of a permanently burning arc is counteracted if at least one blowing region of the conductor trace section 3 has no tinning. An accumulation of electrically insulating material at the end of a blowing region stops arc propagation so that the arc is reliably extinguished, does not cause any other, secondary short-circuits, and thus does not bring about a fire hazard. This is also ensured by the construction of the conductor trace fuse 1 according to Figure 1. A tin coating by soldering tin is provided at the region of the contacts 5 A, 5B. Thus, the

[0058] The conductor trace section 3 is dimensioned such that flow of a current over a defined period of time, wherein the current value is a defined multiple of a nominal current flow, the conductor trace section 3 melts and the current flow via the conductor trace section is thus interrupted. When the conductor trace of the conductor trace section 3 melts, emissions. The emissions can be gaseous and in the form of plasma. The emissions may comprise a particle flow. Emissions in the form of plasma can be associated with the occurrence of an arc.

[0059] Figure 2 shows a schematic view of a second embodiment of a conductor trace fuse 1 according to the invention. Supplementing Figure 1, Figure 2 shows an arrangement of the circuit board 10 and the conductor trace fuse 1 in a housing 22 of an electrical device 20.

[0060] The housing 22 comprises an upper housing half 22B and a lower housing half 22 A Fike the circuit board 10 arranged therein, the housing 22 is shown only in details and in a partially sectional representation. The detail shown here comprises a region of the electrical device 20 in which a mains connection of the electrical device 20 is formed. [0061] The circuit board 10 in Figure 10 shows conductor traces 13 on both sides. A connection block 12 is arranged on the circuit board 10 in a region of the circuit board 10 which is accessible from outside the housing 22. The connection block 12 can have a number of electrical clamping options. The electrical terminals of the connection block 12 enable the electrical device 20 and in particular its on the circuit board 10 to be supplied with electrical current externally. This is shown in Figure 2 with a single electrical line 15 leading to the terminal block 12.

[0062] The connection block 12 can comprise connection terminals for phase conductors, neutral conductors, and protection potential of an AC mains power supply of the electrical device 20. The terminal block 12 may further comprise connection terminals for electrical outputs to further electrical devices, for example for DC supply lines to illuminants.

[0063] Amains input filter (not shown in Figure 2) can be arranged on the circuit board 10 in the vicinity of the connection block 12.

[0064] In the region of the connection block 12, the sectional view of the housing 22 shows an opening which remains when the two upper housing halves 22B and the lower housing half 22A are joined together.

[0065] The second embodiment of the conductor trace fuse 1 comprises the conductor trace section 3 arranged on an inner side of the housing 22. The conductor trace section 3 is shown fixed on the inner side of the housing cover 22B. The conductor trace section 3 can be fastened to the inner side of the housing cover 22B by means of an adhesive bond.

[0066] The conductor trace section 3 can comprise a conductor trace applied to a flexible base material. Alternatively, the conductor trace section 3 is realized in Figure 2 as a conductor trace applied to a flexible base material.

[0067] The conductor trace is dimensioned such that, in the event of an electrical current flow through the conductor trace which corresponds to a rated current of the conductor trace fuse or of the conductor trace section 3, the conductor trace melts in as controlled a manner as possible and prevents a further current flow via the conductor trace section 3. The conductor trace section 3 thus represents the breakthrough region for the conductor trace fuse 1.

[0068] In the exemplary embodiment shown in Figure 1, the first connection section 2A and the second connection section 2B of the conductor trace fuse 1 in each case comprise a first connection subsection 3 A, 3B and a second connection subsection 4A and 4B. Both the first connection section 2A and the second connection section 2B, as well as the second connection subsection 4 A and 4B are realized in Figure 2 as separate conductor traces applied to a common base material.

[0069] The first connection subsection 3 A, 3B is realized, corresponding to the conductor trace section 3, as a conductor trace applied to the flexible base material.

[0070] The second connection subsection 4 A, 4B is realized in Figure 1 as a conductor structure applied in a solid (rigid) base material. The conductor structure of the second connection subsections 4 A, 4B is in each case electrically connected to the first connection subsections 3 A, 3B at a first end.

[0071] A contact 5 A, 5B is arranged in each case at a second end of the second connection subsection 4 A, 4B opposite the conductor trace section 3. The contacts 5 A, 5B are each electrically conductively connected to the conductor structure of the second connection subsections 4 A, 4B, for example via a plug connection and/ or by means of a solder connection.

[0072] The conductor trace section 3 can thus be electrically contacted via the contacts 5 A, 5B. The contacts 5 A, 5B enable an electrically conductive connection of conductor traces 13 (feeds) to the conductor trace section 3 to be produced. The contacts 5 A, 5B are designed as pin contacts in Figure 2.

[0073] The conductor trace fuse 1 shown in Figure 2 makes it possible to arrange the conductor trace section 3 spatially at a distance from a surface of the circuit board 10. In the case shown, the magnitude of the distance is defined by the length of the first connection subsections 3 A, 3B, which have a flexible base material. The conductor trace fuse 1 according to the second exemplary embodiment enables a particularly flexible spatial arrangement of the conductor trace section 3 within the housing 22. This particularly flexible spatial arrangement gives the developer a corresponding number of degrees of freedom in the design of the electrical device 20 for minimizing the effects of the conductor trace section 3 melting when the rated current is exceeded.

[0074] The arrangement according to Figure 2 shows a good shielding of the opening of the housing 22 in the region of the connection block 12 with respect to emitted particles, gases, and plasma, in the event of the conductor trace section 3 melting. At the same time, an enlarged spatial distance from the components 11 of the circuit that are adjacent leftward is achieved. [0075] The conductor trace fuse 1, in particular the conductor trace section 3, the first connection section 2 A, 2B, and the second connection section 2B can be manufactured in one piece or can be produced individually in several parts and subsequently assembled. The conductor trace fuse 1 manufactured in several parts can be assembled prior to being mounted on the circuit board 10 or can be assembled with its parts individually on the circuit board 10.

[0076] Figure 3 shows a side view of a circuit board 10 with a conductor trace fuse 1 according to the invention arranged in an electrical device 20.

[0077] The circuit board 10, also referred to as a board, carries a preferably printed circuit (printed circuit board, abbreviated to PCB), which constitutes an electrical circuit. The term “electrical circuit’’ is to be understood here as synonymous with electronic circuit. For improved clarity, the circuit board 10 is shown without conductor traces in Figure 3. Individual components 11 of an electrical circuit are shown on the circuit board 10.

[0078] A conductor trace fuse 1 is shown in the left-hand portion of the printed circuit board 10. The conductor trace fuse 1 is here arranged spatially between a connection block 12 and the other components 11 of the circuit on the circuit board 10. The connection block 12 provides an electrical interface of the electrical device 20. For this purpose, the connection block has a plurality of electrical terminals which are designed for receiving electrical connecting lines. An electrical input interface and/ or an electrical output interface of the electrical device 20 can be provided via the illustrated connection block 12.

[0079] The mains power can be supplied to the electrical device 20, for example with phase, neutral conductor, and protective conductor, via the connection block 12. Amains input filter can be arranged, spatially adjacent to the connection block 12, on the circuit board 10.

[0080] The terminal block 12 can also have connection options for data connections, bus lines etc.

[0081 ] The connection block 12 can also have clamping options for output lines of the electrical device 20 in addition to the terminals for a mains voltage supply. If the electrical device 20 is an operating device for illuminants, the terminal block 12 can have two or more connection options for outputting a load current, especially a direct current (DC), to the illuminants.

[0082] This spatial arrangement of the conductor trace fuse 1 on the circuit board 1 reflects the functional task of the conductor trace fuse 1: in the event of a short-circuit in the circuit, the resulting short-circuit current leads to a melting of the conductor trace fuse and thus to a controlled interruption of the current flow via the conductor trace fuse 1. The circuit region of the circuit in the components 11 shown on the right is thus separated from the left-hand circuit region of the circuit on the circuit board 10.

[0083] The printed circuit board 10 is accommodated in a housing 22 (assembly housing), which in Figure 3 is shown open and with the printed circuit board 10 removed. The housing 22 comprises a lower housing part 22 A, which receives the circuit board 10 and surrounds the circuit board 10 substantially toward the bottom and toward the sides of the circuit board 10. A second housing part 22B is placed on the lower housing part 22A and closes off the housing 22 toward the top, so that the circuit board 10 is located almost completely within the housing 22 when the housing 22 is closed. Since the upper housing part 22B, in a main extension direction of the housing 22 and of the printed circuit board 10, is formed somewhat shorter than the lower housing part 22A and the printed circuit board 10, the outermost left-hand portion of the printed circuit board 10, which is nearly completely covered by the terminal block 12 mounted thereon, remains accessible from above, and can thus provide clamping options for the electrical device 20 that are accessible from the outside.

[0084] In the assembled state, the illustrated design of the upper housing part 22B and the lower housing part 22Aresults in an opening between the upper housing part 22B and the lower housing part 22A, which opening is partially, but not quite completely, closed by the connection block 12. This opening of the housing 22 can lead to plasma, gases, and/or material entering the surroundings of the housing 22 when the conductor trace fuse 1 trips. Under certain circumstances, this may cause consequential damage, for example fires in the surroundings of the electrical device 20.

[0085] According to one embodiment of the invention, the conductor trace fuse 1, at least with its blowing region, is not, as previously known, arranged as a conductor trace section on the surface of the circuit board 10 but is arranged corresponding to the length of the first and second connection sections 2A, 2B at a distance D perpendicular to the main extension directions of the circuit board 10 above the surface of the circuit board 10. The conductor trace fuse 1 is thus advantageously arranged in relation to the opening of the housing 22 in order to reduce the escape of plasma when the conductor trace fuse 1 melts.

[0086] As a result of special designs of the housing 22, in particular webs or comparable cover elements, the conductor trace fuse 1 can in particular also be arranged shielded from sensitive regions in the interior of the housing 22. Sensitive regions can in particular be the opening(s) and/ or parts of the circuit and/ components on the circuit board 10.

[0087] In combination with an existing opening of the housing 22, this reduces the risk of hot plasma, gases, and/or splitter material escaping through the opening into surroundings of the electrical device 20. Damage in the surroundings due to the short-circuit within the electrical device 20 can thus be prevented, in particular also that no fires are started. The opening of the housing 22 can comprise a connection opening of the housing 22 and in particular an opening for input connections of a mains power supply of the electrical device 20. Furthermore, the opening can also enable access to output connections of the electrical device 22. If the electrical device 20 is, for example, an electrical operating device for illuminants 21, the opening can enable a user to connect an illuminant 21, in particular also designed as an LED illuminant.

[0088] The device 20 according to the invention can thus prevent damage to objects in the surroundings of the electrical device 20 and to persons.

[0089] The electrical device 20 described above can in particular be an electronic device, such as an operating device (driver, ballast) for illuminants.

[0090] According to an alternative embodiment of the invention, at least one of the connection subsections can be designed as a kind of additional circuit board which can be mounted and contacted on the circuit board 10, for example by means of a solder connection. For example, the second connection subsection 4 A, 4B can be designed as an additional circuit board and a contact 5 A, 5B is arranged thereon in each case. The contacts 5 A, 5B are each electrically conductively connected to the conductor structure of the second connection subsections 4A, 4B, for example via a plug connection and/ or by means of a solder connection.

[0091 ] The additional circuit board can also have further components of the electrical device.

[0092] The conductor trace fuse 1 defined in the claims, arrangement comprising the conductor trace fuse 1 and circuit board 10, and the electrical device 20 are in particular advantageously commercially applicable in the field of electrical equipment in lighting technology.

Claims

Claims:

1. Conductor trace fuse for an electrical device, comprising a first and a second connection section (2 A, 2B), and a conductor trace section (3) arranged between the first and second connection sections (2 A, 2B), and characterized in that the conductor trace section (3) and/ or at least the first or second connection sections (2A, 2B) is constructed as a conductor trace that is flexible at least in subsections.

2. Conductor trace fuse according to Claim 1, characterized in that the first and second connection sections (2A, 2B) each comprise a rigid subsection (4 A, 4B), and the rigid subsections (4 A, 4B) each have a contact region (5 A, 5B) for electrical and mechanical connection to a circuit board (10).

3. Conductor trace fuse according to Claim 2, characterized in that the conductor trace section (3) and/ or at least the first or the second connection sections (2A, 2B) are each arranged on a side (6A, 6B) of the rigid subsection (4A, 4B) which faces away from the fastening region (5A, 5B) and is arranged at a distance therefrom.

4. Conductor trace fuse according to Claims 2 or 3, characterized in that the rigid subsection (4 A) of the first connection section (2 A) and the rigid subsection (4B) of the second connection section (2B) are arranged substantially parallel to one another.

5. Conductor trace fuse according to any one of the preceding claims, characterized in that the conductor trace section (3) is constructed as a flexible conductor trace, which connects the rigid first and the second connection section (2A, 2B).

6. Arrangement comprising a circuit board (10) and a conductor trace fuse (1) according to any one of the preceding claims.

7. Arrangement according to Claim 6, characterized in that the conductor trace section (3) is arranged at a distance from the circuit board (10).

8. Arrangement according to Claim 7, characterized in that the conductor trace fuse (3) is arranged at a distance above or below a plane of the circuit board (10).

9. Arrangement according to any one of Claims 6 to 8, characterized in that the conductor trace fuse (3) is arranged in an orientation deviating from the main extension directions of the circuit board (10).

10. Electrical device, in particular operating device (20) for illuminants (21), comprising at least one arrangement according to any one of Claims 6 to 9.

11. Electrical device according to Claim 10, characterized in that the electrical device comprises a housing (22) and a connection block (12) arranged on the housing (22), and the conductor trace fuse (1) is arranged at a distance from the connection block (12) within the housing (22).