Printed wire protection device

Abstract

A printed conductor fuse device (1) for an electrical or electronic device, the printed conductor fuse device having a first connection area and a second connection area (2a, 2b), a non-linearly extending burnout area (3) arranged between the first connection area and the second connection area (2a, 2b), and a covering element (5) having at least two side walls (9) and a covering surface (8), the covering element being arranged above the first connection area, the second connection area (2a, 2b), and the burnout area (3), wherein the burnout area (3) and the covering element (5) are arranged relative to each other such that the surface of the covering surface (8) covers the burnout area (3) and a cavity (7) is formed between the burnout area (3) and the covering surface (8) by the height of the side walls (9).

Description

[0001] The present invention relates to a printed conductor fuse device for electrical protection of electrical equipment. Prior art

[0002] Printed conductor fuse devices are already known from the prior art. The printed conductor fuse device is applied to a printed circuit board or circuit board and has the task of quickly and reliably disconnecting the electrical connection to the power supply in the event of an abnormal operating state, such as a short circuit of an electrical component on the circuit board. Thereby, in particular, further damage to the circuit board or the electrical components located thereon can be avoided. Further, it is possible to prevent the triggering of the grid protection switch by triggering the printed conductor fuse device in advance.

[0003] In addition, by providing a printed conductor fuse device on the circuit board, it is possible to replace the fine wire fuse devices commonly used for protecting electrical or electronic equipment.

[0004] The printed conductor fuse device typically has at least one printed conductor section that is implemented as a fuse device or a fuse conductor. Herein, the printed conductor section has a narrowed cross-section compared to other printed conductors on the circuit board. The fuse conductor is heated by the current flowing through it, and when the rated current of the fuse conductor is significantly exceeded, the fuse conductor melts or evaporates, which causes the circuit to break.

[0005] It should be noted here that possible arcs are extinguished in a controlled manner and in particular cannot reach other conductor lines. In particular, it should be prevented that the plasma occurring when the fuse device melts or evaporates finds new charged contact pairs and thereby continues to burn in an uncontrolled manner and thereby causes further damage on the circuit board.

[0006] DE 100 05 836B4 describes a printed circuit board for an electrical or electronic device, which printed circuit board has a printed circuit board fuse device, wherein the printed circuit board bears the conductor lines to be fused, and wherein the conductor lines have a region with a reduced cross-section as a burn-through region and are provided with a non-conductive coating. In addition, the conductor lines have at least two accumulations made of non-conductive material that are arranged spaced apart from each other on the burn-through region and are spaced apart from each other in the longitudinal direction of the conductor lines and are provided in addition to the coating. Summary of the invention

[0007] Starting from this known prior art, the object of the present invention is to provide a printed conductor fuse device for a printed circuit board or circuit board that can be produced at low cost and that enables a safe and reliable interruption of the current supply to the circuit board in the event of a fault and thus improves the operating reliability of the circuit board.

[0008] According to the present invention, this object is achieved by the features of claim 1. Particularly advantageous embodiments of the present invention are described in the dependent claims.

[0009] In a first aspect, the present invention relates to a printed wire fuse device for an electrical or electronic device, the printed wire fuse device having a first connection area and a second connection area, a non-linearly extending burnout area arranged between the first connection area and the second connection area, and a continuous covering area, the covering area being at least partially arranged above the first connection area, the second connection area, and the burnout area, wherein the burnout area and the covering area are arranged such that at least one triggering area of the burnout area is not covered by the covering area, but is defined by the covering area on both sides.

[0010] The present invention makes it possible to provide a printed wire fuse device that can be simply manufactured but is very effective at the same time. By means of this printed wire fuse device, the operating reliability of electrical or electronic devices is improved.

[0011] In an advantageous embodiment of the present invention, the burnout area has at least a partially curved or partially serrated orientation in a top view. The curved or serrated orientation of the burnout area preferably extends along the main extension direction of the burnout area. The main extension direction of the burnout area preferably corresponds to the direct connection of the first connection area and the second connection area of the printed wire fuse device in a top view. The curved or serrated orientation of the burnout area preferably extends to the same extent on both sides of the main extension direction of the burnout area.

[0012] In another preferred embodiment, the curved or serrated orientation can also be formed such that the orientation of the burnout area extends further towards one side of the main extension direction of the burnout area than towards the opposite side of the main extension direction.

[0013] Furthermore, the burnout area can also have a non-linear orientation of different shapes.

[0014] The manufacturing time and manufacturing cost of the printed wire fuse device can be reduced. At the same time, reliable protection of the circuit board is made possible by means of the printed wire fuse device according to the present invention.

[0015] The burnout area of the printed wire fuse device is preferably an un-tinned copper conductor, and the burnout area has a reduced cross-section relative to the first connection area and the second connection area. However, the burnout area can also be formed of other materials, such as fine silver. The cross-section of the burnout area preferably lies between 0.05 mm and 1 mm.

[0016] In the case where the current borne by the burn-through area significantly exceeds its rated current, evaporation or melting occurs in the burn-through area. Further, a covering element of the printed conductor fuse ensures that the plasma generated therein does not reach other live contact pairs.

[0017] In this way, a printed conductor fuse with a defined triggering area is provided, in which the plasma generated when the burn-through area evaporates is kept as small as possible.

[0018] In a second aspect, the invention describes a printed circuit board having a printed conductor fuse with the above-described features.

[0019] Thus, the invention makes it possible to increase the operating reliability of a printed circuit board using a simply manufacturable printed conductor fuse.

[0020] In another aspect, the invention describes an operating device for a light-emitting device, the operating device having a printed conductor fuse according to the invention. Description of the Drawings

[0021] Advantageous embodiments of the invention are shown in the following drawings and are further elaborated with the aid of the following description.

[0022] Figure 1 A schematic cross-section of a printed conductor fuse according to the invention according to a first embodiment is shown.

[0023] Figure 2 A schematic top view of a printed conductor fuse according to the invention according to a second embodiment is shown.

[0024] Figure 3 A printed circuit board of an electrical or electronic device is shown, the printed circuit board having a printed conductor fuse according to the invention.

[0025] Figure 4 An embodiment according to the invention of a covering element is shown. Detailed Description

[0026] Figure 2 A schematic top view of a printed conductor fuse 1 according to the invention according to a first embodiment is shown. The printed conductor fuse 1 is applied to a printed circuit board or circuit board 20 and has a first connection area and a second connection area 2a, 2b. The connection areas 2a, 2b are arranged at a spacing D, which is preferably between 3 mm and 15 mm.

[0027] A burnout region 3 is arranged between the first connection region and the second connection regions 2a, 2b, and the burnout region is in electrical contact with the first connection region and the second connection regions. The burnout region has a cross-section d', which is reduced relative to the cross-section d of the first connection region and the second connection regions 2a, 2b. Advantageously, the cross-section d' of the burnout region 3 is also reduced relative to the remaining printed conductors 5, 6 (see Figure 3 ) located on the circuit board 20.

[0028] Wherein, the cross-section d' of the burnout region 3 is dimensioned such that the burnout region evaporates or melts when the rated current of the printed conductor fuse device 1 is exceeded.

[0029] The burnout region 3 is preferably arranged non-linearly between the first connection region and the second connection regions 2a, 2b. In a preferred embodiment, the burnout region 3 has a zigzag course extending along the main extension direction Z.

[0030] Wherein, the main extension direction Z preferably corresponds to the direct connection or the shortest connection between the first connection region and the second connection regions 2a, 2b.

[0031] The zigzag course of the burnout region 3 preferably extends to the same extent Y, Y' on both sides of the main extension direction Z. However, it is also feasible that the zigzag course extends from the main extension direction Z to different extents Y, Y'.

[0032] Figure 2 A schematic top view of a printed conductor fuse device 1 for an electrical or electronic device according to the present invention is shown. The printed conductor fuse device has a first connection region and a second connection regions 2a, 2b, a burnout region 3 arranged between the first connection region and the second connection regions 2a, 2b and extending linearly or non-linearly, and a covering element 5 having at least two side walls 9 and a covering surface 8. The covering element 5 is arranged above the first connection region and the second connection regions 2a, 2b and the burnout region 3. The burnout region 3 and the covering element 5 are arranged such that the surface of the covering surface 8 covers the burnout region 3 and a cavity 7 is formed between the burnout region 3 and the covering surface 8 by the height of the side walls 9.

[0033] In the top view, the burnout region 3 can have a linear course, a zigzag course, or at least a partially curved or angled course.

[0034] The side walls 9 are arranged parallel to the main extension direction of the burnout region 3.

[0035] The burnout region 3 has a cross-section d' that is reduced relative to the first connection region and the second connection regions 2a, 2b.

[0036] The covering element 5 having at least two side walls 9 is preferably formed uniformly and has a constant thickness t.

[0037] The covering element 5 can be formed such that the side walls 9 do not completely enclose the cavity 7, thereby forming an exhaust opening 10 at the end face of the covering element 5 in a top view of the printed conductor fuse device.

[0038] The covering element 5 can have a bounding wall 11 arranged relative to the exhaust opening 10, and this bounding wall is arranged such that it connects two side walls 9 at the end of the covering element 5.

[0039] The burnout area 3 can be an un-tinned copper conductor.

[0040] The covering surface 8 can also have a surface enlarged by corrugations or ribs.

[0041] The covering element 5 can also be implemented as circular or oval, and thus has side walls in a rounded shape.

[0042] A tab can be arranged in the exhaust opening 10 of the covering element 5. Such a tab can prevent the exhaust opening 10 from being closed during the soldering process when assembling the operating equipment.

[0043] Thus, the printed circuit board 20 can be formed according to the invention, and this printed circuit board has a printed conductor fuse device 1 with the above-described characteristics.

[0044] The covering element 5 can be fixed to the printed circuit board 20 by means of the lower side of the side walls 9 and is preferably connected by means of a connecting element 4.

[0045] The connecting element 4 can be a rod or bar made of a non-conductive material, preferably SMD adhesive or solder mask paint.

[0046] The connecting element 4 can be applied by means of a stencil.

[0047] By means of the covering element 5, evaporation or melting to generate a plasma for the remaining burnout area 3 is avoided, and this covering element cools the printed conductor 6 located below it.

[0048] The cross-section d” of at least one triggering area 3a is preferably equal to the cross-section d' of the burnout area 3.

[0049] In an alternative embodiment, at least one triggering area 3a has a cross-section d” which is further reduced relative to the cross-section d' of the burnout area 3.

[0050] In a preferred embodiment, the printed conductor fuse device 1 has several triggering areas 3a. Preferably, there are three triggering areas 3a, 3b, 3c, and these triggering areas are each bounded by the covering element 5 on both sides.

[0051] The covering element 5 is linearly arranged on the circuit board 20 between the first connection region and the second connection regions 2a, 2b and thus follows the main extension direction Z of the burnout region 3. Herein, the covering element 5 has a constant width B. This width B is preferably smaller than the sum of the extension lengths Y and Y' of the burnout region 3, which extension lengths are arranged at right angles to the main extension direction Z.

[0052] Furthermore, the covering element 5 is preferably arranged centered with respect to the main extension direction Z on the circuit board 20.

[0053] Figure 1 A schematic cross-section at the section line A-A of a printed conductor fuse device according to the invention according to the second and third embodiments is shown. This embodiment basically corresponds to the embodiment according to Figure 2 with the section line A-A, wherein the same components are provided with the same reference numerals.

[0054] According to the embodiment shown in Figure 2 the burnout region 3 has at least partially an angular or right-angled course. At least one trigger region 3a is in turn delimited towards both sides by the covering element 5.

[0055] Thereby, a printed conductor fuse device according to the invention can be manufactured in a simplified manner. Herein, the connection regions 2a, 2b (which connection regions are preferably electrically connected to further printed conductors of the circuit board 20) are applied to the circuit board 20 together with these further printed conductors. In the same or subsequent method steps, the printed conductor forming the burnout region 3 can be applied to the circuit board 20 between the first connection region and the second connection regions 2a, 2b.

[0056] The printed conductor being "applied" to the printed circuit board 20 can in particular also be understood as etching the corresponding printed conductor from a thin copper layer located on the printed circuit board.

[0057] In subsequent method steps, the connection element 4 can be applied to the printed circuit board 20. Herein, the covering region 4 is preferably applied by means of a stencil. In a simultaneous step, a uniform thickness of the connection element 4 can be achieved by scraping or dispensing. In a further step, the covering element 5 is applied.

[0058] In an alternative variant, the connection element 4 can also be formed by solder and the covering element 5 can be fixed, for example, during a reflow soldering process.

[0059] Of particular importance is obtaining the vent opening 10.

[0060] Thereby, the covering element 5 can be used as an anti-corrosion or anti-contact device.

[0061] The connecting element 4 is formed in a film-like manner as visible in Figure 2 and is preferably made of a non-conductive material, such as solder mask or SMD adhesive.

[0062] Furthermore, the connecting element 4 and / or the covering element 5 may contain an arc quenching substance.

[0063] When the connecting element 4 is formed by SMD adhesive, the application of the connecting element 4 is preferably carried out in one step together with the application of the bonding points on the circuit board 20 during the manufacture of the circuit board.

[0064] Thereby, the selective application of the connecting element 4 can be carried out in one step together with the application of the bonding points on the circuit board 20.

[0065] Thereby, a simplified manufacturing process of the printed circuit board 20 is possible.

[0066] Figure 3 A ballast 30 for a light-emitting device is shown, which ballast has a circuit board 20 on which printed conductors 50, 6 forming the operating equipment of the light-emitting device are applied. Among them, the ballast 30 has a printed conductor protection device 1 according to the present invention.

[0067] Among them, the circuit board 20 is located inside the housing 30a of the device 30. The printed conductors 5, 6 are in contact with an external power supply (not shown), such as a 230V power grid.

[0068] The printed conductor 6 is in electrical contact with the printed conductor protection device 1 according to the present invention. Thereby, the electrical protection of the printed conductor 6 and thus the electrical protection of the electrical device 30 are made possible.

[0069] Thereby, a short circuit or abnormal operating state generated in the circuit can be reliably interrupted by the printed conductor protection device 1, and the short circuit or abnormal operating state causes the current in the printed conductors 50, 6 to significantly exceed the rated current of the printed conductor protection device 1.

[0070] Preferably, the printed conductor protection device is arranged in the operating equipment such that the exhaust opening 10 is arranged in a direction opposite to the terminal for contacting the power grid interface of the operating equipment, so that the exhaust of the printed conductor protection device is carried out in the direction of the inside of the operating equipment. Typically, the printed conductor protection device is arranged near the terminal for contacting the power grid interface of the operating equipment within the housing 30a. Preferably, the printed conductor protection device is arranged in the operating equipment having the housing 30a such that the exhaust opening 10 points in the direction of the inside of the housing 30a, that is, in a direction opposite to the terminal for contacting the power grid interface of the operating equipment or other openings at the side of the housing 30a.

[0071] In the event of a fault, i.e., for example, when a current of 160 A DC is fed to the grid interface of the operating device, the printed conductor fuse device is triggered. This high current causes an explosive combustion of the conductor material of the printed conductor fuse device and the formation of a plasma. The energy released propagates to where there is no or only very little resistance.

[0072] However, the covering element 5 arranged above the burn-through area 3 prevents the energy from propagating in an uncontrolled manner. Through the exhaust opening 10, the covering element 5 is open in one direction. The size and position of the exhaust opening 10 can be determined individually according to the size and shape of the printed conductor fuse device. By means of the corresponding orientation of the covering element 5 with the exhaust opening 10 in the housing 30a, the direction of the energy released by the printed conductor fuse device can be selected, and thus the energy can be guided into the area of the housing 30a where the energy can be sufficiently absorbed before entering the outer area of the housing 30a.

[0073] Figure 4 An exemplary embodiment of the covering element 5 is shown. For example, the covering element 5 can be provided only for a single burn-through area 3 and thus for a single printed conductor 6, where several individual covering elements 5 can be provided for several individual burn-through areas 3.

Claims

1. A printed wire fuse device (1) for an electrical or electronic device, the printed wire fuse device having a first connection area and a second connection area (2a, 2b), a burnout area (3) arranged between the first connection area and the second connection area (2a, 2b) and extending linearly or non-linearly, and a covering element (5) having at least two side walls (9) and a covering surface (8), the covering element being arranged above the first connection area and the second connection area (2a, 2b) and the burnout area (3), wherein the burnout area (3) and the covering element (5) are arranged relative to each other such that the surface of the covering surface (8) covers the burnout area (3) and a cavity (7) is formed between the burnout area (3) and the covering surface (8) by the height of the side walls (9), characterized in that, The covering element (5) is formed such that the side walls (9) do not completely surround the cavity (7), so that an exhaust opening (10) is formed at the end face of the covering element (5) in a top view of the printed conductor fuse device.

2. The printed wire protection device (1) according to claim 1, characterized in that, The burn-through area (3) has a zigzag course in a top view.

3. The printed wire protection device (1) according to claim 1, characterized in that, The burn-through area (3) has at least partially curved or angled course in a top view.

4. The printed wire protection device (1) according to one of claims 1 to 3, characterized in that, The side walls (9) are arranged parallel to the main extension direction of the burn-through area (3).

5. The printed wire protection device (1) according to claim 1, characterized in that, The burn-through area (3) has a reduced cross-section relative to the first and second connection areas (2a, 2b).

6. The printed wire protection device (1) according to claim 1, characterized in that, The covering element (5) having the at least two side walls (9) is formed uniformly and has a constant thickness.

7. The printed wire fuse device (1) according to claim 1, characterized in that, The covering element (5) has a delimiting wall (11) arranged relative to the exhaust opening (10), and the delimiting wall is arranged such that the delimiting wall connects the two side walls (9) at the end of the covering element (5).

8. The printed wire protection device (1) according to claim 1, characterized in that, The burn-through area (3) is an un-tinned copper conductor.

9. A printed circuit board (20) having a printed conductor fuse device (1) according to one of claims 1 to 8.

10. The printed circuit board (20) according to claim 9, characterized in that, The covering element (5) is fixed to the printed circuit board (20) by means of the lower side of the side walls (9).

11. The printed circuit board (20) according to claim 10, characterized in that, The connecting element (4) is a rod or strip made of non-conductive material.

12. The printed circuit board (20) according to claim 11, characterized in that, The connecting element (4) can be applied by means of a template.

13. The printed circuit board (20) according to claim 10, characterized in that, The covering element (5) is connected to the printed circuit board (20) by means of the lower side of the side walls (9) by means of the connecting element (4).

14. The printed circuit board (20) according to claim 11, wherein, The connecting element (4) is a rod or strip made of SMD adhesive or solder mask.

15. An operating device for a light-emitting device, the operating device having a printed conductor fuse device (1) according to one of claims 1 to 8 and a printed circuit board (20) according to one of claims 9 to 14.

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