Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/46—Circuit arrangements not adapted to a particular application of the protective device
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
  • H01H85/041—Fuses, i.e. expendable parts of the protective device, e.g. cartridges characterised by the type
  • H01H85/0411—Miniature fuses
  • H01H2085/0412—Miniature fuses specially adapted for being mounted on a printed circuit board

Definitions

• the invention relates to a component with an internal conductor track, which is designed such that it is severed at a predetermined point to form an arc if predetermined current / voltage conditions occur at connections of the component.
• a component of the type mentioned at the outset is, for example, a fuse component in the form of a chip fuse. If the current flow through the chip fuse exceeds a maximum value for a predetermined duration, the fuse may cut out, i.e. to cut a fuse element. Starting at the point of separation, the fuse component forms
• the object of the invention is therefore to provide a component with which a fuse component can be produced, in which a reduced current flow in the event of a shutdown is possible without negatively influencing the operating parameters in normal operation (before switching off).
• the main idea of the invention is to use the energy released when the arc is switched off in such a way that the electrical properties of a circuit element of a component are changed in a desired manner, that is to say the component is reconfigured.
• the component can be a two-pole system with two connections, the change in the electrical properties of the circuit element caused by the arc leading to a changed two-pole behavior of the component.
• the internal conductor path cut through by the arc and the circuit element, the electrical properties of which are changed could be connected to separate connections of the component.
• the component is a layer component in which the conductor track and the circuit element are formed from structured layers on a substrate.
• the conductor track and the circuit element are formed from structured layers on a substrate.
• the circuit element reconfigured by the arc can be, for example, any two-pole connection.
• this two-pole circuit changes its electrical resistance when the arc acts; preferably the resistance is increased.
• the circuit element is a second conductor, which is severed when the arc is affected.
• the internal ternal conductor strip is cut to form the arc and then also cuts the second conductor strip as a result of this arc.
• the second conductor preferably crosses the internal conductor at the predetermined point at which the internal conductor is cut to form the arc.
• a preferred embodiment of the component is characterized in that a resistance element is connected in the component parallel to the second conductor, on which the arc can act.
• the parallel connection formed in this way has a very low resistance before the action of the arc and the resistance of the resistance element alone after the action of the arc.
• This parallel connection of circuit element and resistance element is preferably connected in series with the internal conductor track, which is severed to form the arc.
• This series connection has a very low resistance before the formation of an arc, namely that of the series connection of the internal conductor line and the second conductor line.
• Under predetermined current / voltage conditions at the connections of the component for example when a high current is flowing, the internal conductor path is cut to form the arc.
• the second conductor line is also cut.
• the resistance element is connected in series with the still existing arc of the internal conductor track. The resistance element then limits the current flow through the arc.
• the latter embodiment is preferably used as a fuse component, the internal conductor being cut to form an arc if a current through the conductor exceeds a maximum value for an associated maximum duration.
• a "shutdown" can take place at different currents, with a shorter current flow time at higher current values is required to switch off.
• Such a fuse component has the advantage that a resistance is switched into the current path in the event of switching off with an arc that arises in the process.
• the resistance ie the resistance element
• the resistance element connected in parallel with the second conductor track has a resistance between 5 ⁇ and 20 ⁇ .
• the dimensioning of the resistance element depends on the application of the fuse component, in particular on the switch-off current and the maximum voltage present.
• the internal and the second conductor track and the resistance element are formed from structured layers on a substrate, the internal conductor track being arranged over a section of the second conductor track and being separated from it by an electrically insulating layer.
• the internal conductor track crosses the second conductor track covered with an insulator layer.
• FIG. 1A shows a schematic illustration of the essential elements of the layout of a fuse component according to the invention in normal operation
• FIG. 1B shows a circuit diagram of the fuse component according to FIG. 1A
• 2A shows a schematic illustration of the essential elements of the layout of the fuse component according to FIG. 1A after the formation of an arc when the fuse component is cut
• FIG. 2B shows a basic circuit diagram of the fuse component according to FIG. 2A after the arc has been formed.
• FIG. 1A shows a schematic top view of the top of a component 1.
• a substrate 2 for example an Al 2 O 3 substrate or another ceramic substrate, there are a number of layers
• FIG. 1A shows only the layers essential to the invention. In addition to the layers shown, a number of further layers can be applied under, between or over the layers shown, for example insulator, cover, protective layers and layers which influence the heat dissipation.
• a first conductive layer 5 is applied and structured on the substrate 2, which in addition to the connection areas 6 and 7 comprises a conductor run 8 running transversely to the longitudinal direction of the substrate 2.
• the conductor 8 is part of a U-shaped conductor loop in the conductive layer 5.
• a resistance layer 9 is applied, which is structured in such a way that an approximately rectangular region of the resistance layer forms the legs of the U-shaped conductor loop at its upper ends combines.
• the resistance layer 9 could also be arranged under the conductive layer 5.
• This arrangement of the structured resistance layer 9 and the structured guide layer 5 creates a parallel connection between a resistor and a U-shaped conductor loop, a connection of the parallel connection being connected directly to the contact surface 6.
• An electrically insulating layer (not shown in FIG. 1 a) is applied over the conductive layer 5 and at least one further structured conductive layer 3 is applied to this insulator layer.
• the further conductive layer 3 is structured such that it forms a conductor strip which overlaps the contact surface 7 at one end and overlaps the U-shaped conductor strip at its other end.
• a window is formed in the insulator layer arranged between the conductive layer 5 and the at least one further conductive layer 3, so that contacts can be made between the conductive layer 5 and the conductive layer 3 at these locations.
• the contact of the conductive layer 3 to the underlying conductive layer 5 in the U-shaped conductor track area is at that end of the U-shaped conductor loop which forms the node of the parallel connection of the resistance layer 9 and the U-shaped conductor loop which is not connected to the contact surface 6.
• a section 4 of the at least one further conductive layer 3 crosses the conductor run 8. The section 4 of the conductive layer 3 crossing the conductor run 8 is separated from the conductor run 8 by the insulator layer.
• section 4 of the at least one conductive layer 3 is designed as a fusible conductor element, for example (as shown in FIG. 1A) of smaller width than the rest of the conductive path formed in conductive layer 3.
• the section 4 forming the fusible conductor element in the at least one conductive layer 3 can, for example, contain a thick-layer conductor containing silver and additionally a solder layer applied thereon.
• FIG. 1B shows a circuit diagram of the arrangement shown schematically in FIG. 1A.
• the contact areas 6 and 7 correspond to the connections 16 and 17, respectively.
• the U-shaped conductor loop in the conductive layer 5 corresponds to the short-circuit connection 18.
• the resistance element formed in the resistance layer 9 corresponds to the resistor R 19.
• the fusible conductor element formed in the at least one second conductive layer 3 in section 4 corresponds to the fusible conductor element 14 in FIG. IB.
• Fusible conductor element 14 remains intact, the current flows essentially via the short-circuit connection 18 and the fusible conductor element 14 between the connections 16 and 17.
• the component 1 has a low ohmic resistance. If the current flow through the component 1 exceeds a certain current strength for a predetermined period of time, the fusible conductor element 14, ie the section 4 in the conductive layer 3, is severed. The process of severing (switching off) depends on the structure of the fuse element.
• a conductive layer 3 containing silver particles is covered at a predetermined location by a solder layer (which contains tin and lead) and if the flow of the current causes the component to heat up, the conductive layer is severed due to a complex process which involves the melting of the Solder metal, the diffusion of the metal into the silver layer, the increase in the resistivity of the conductive layer, the local heating and the evaporation of the conductive layer.
• the process of severing is primarily determined by the evaporation of the conductive layer material as a result of local heating.
• FIGS. 2A and 2B schematically show the fuse component 1 shown in FIG. 1A or the circuit shown in FIG. 1B in the event that an arc 10 has formed in the region of the severed section 4 of the conductive layer. While the arc 10 evaporates the material of the section 4, the energy of the arc simultaneously leads to an evaporation of the material of the insulator layer underneath and part of the material of the conductive layer 5 in the conductor track 8 lying under the insulator layer finally severed.
• the thickness of the insulator layer between the conductive layer 3 and the conductive layer 5 in the region of the conductor track 8 must be selected so that it provides adequate electrical insulation on the one hand, and is as thin as possible on the other hand so that the greatest possible proportion of the arc energy acts on the conductive layer 5 to allow the conductor track 8.
• the combination of the conductive layer 5 (in the conductor area 8) and the insulator layer must be designed such that ignition of an arc between the section of the interrupted conductor 8 connected to the connection 6 and the section of the conductive layer 3 connected to the connection 7 is avoided. This can be achieved through a suitable layout design and insulator layer thickness.
• FIG. 2B shows the circuit diagram that results when the arc 10 is ignited and the conductor track 8 has already been cut.
• the short-circuit connection 18 connected in parallel with the resistor 19 is severed, so that the resistor R19 is connected in series with the arc 10 between the connections 16 and 17.
• the resistor R thus limits the current flowing over the arc 10.
• the harnessing of the resistance 19, both with regard to the resulting ohmic resistance R and also with regard to the current absorption capacity (maximum power loss) depends on several factors which depend on the maximum voltage present between contacts 16 and 17 and the desired maximum current (short-circuit current). In one embodiment, R could have a resistance between 5 ⁇ and 20 ⁇ , for example 10 ⁇ .
• the layout shown in FIG. 1A could be modified considerably (with the circuit diagram being the same per se).
• the order of the layer application could also be changed.
• the conductor run 8 could be arranged parallel to the section 4 of the conductor run 3 or, if the conductor run 8 is U-shaped, cross the section 4 twice.
• the energy of the arc could also be used to modify a layer applied to the substrate 2 without evaporating it.
• the action of the arc could increase the sheet resistance, for example through alloying effects.

Landscapes

• Fuses (AREA)
• Discharge Heating (AREA)
• Lasers (AREA)
• Semiconductor Lasers (AREA)
• Led Devices (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=31984217

Family Applications (1)

Country Status (5)

Families Citing this family (5)

Family Cites Families (20)

• 2002
  • 2002-09-28 DE DE10245393A patent/DE10245393A1/de not_active Withdrawn
• 2003
  • 2003-08-27 AT AT03750445T patent/ATE341096T1/de not_active IP Right Cessation
  • 2003-08-27 WO PCT/EP2003/009458 patent/WO2004034416A1/fr active IP Right Grant
  • 2003-08-27 DE DE50305199T patent/DE50305199D1/de not_active Expired - Lifetime
  • 2003-08-27 EP EP03750445A patent/EP1547113B1/fr not_active Expired - Lifetime
  • 2003-08-27 US US10/529,468 patent/US7417526B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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