Circuit breaker device with a multilayer substrate for the mechanical arrangement and connection of electronic components

Abstract

Circuit breaker device (10) for automatically switching off an electrical circuit when permissible current and / or voltage values ​​are exceeded, comprising a multi-layer substrate (1) for the mechanical arrangement and connection of electronic components (6), wherein the multi-layer substrate (1) has at least one carrier layer (2) for attaching the electronic components (6) to at least one surface (2a) of the carrier layer (2) and at least one cover layer (3) for covering the electronic components (6), wherein the carrier layer (2) and the cover layer (3) have a dielectric material and form a hermetically sealed housing.

Description

[0001] The present invention relates to a circuit breaker device for automatically switching off an electrical circuit when permissible current and / or voltage values ​​are exceeded, comprising a multilayer substrate for the mechanical arrangement and connection of electronic components.

[0002] Basic circuit breaker devices or protective switching devices automatically disconnect an electrical circuit as soon as, for example, its rated current is exceeded by a defined factor, so that, for example, the consumer located in the line downstream of the circuit breaker or even the line itself is protected from damage or destruction due to the thermal effect of the current. It is also known that circuit breakers or protective switching devices have two tripping systems, such as the thermal release and the electromagnetic release. The thermal release, for example, has a bimetallic strip consisting of two metal strips with different thermal expansion coefficients rolled onto one another. The current from the connected consumer flows, for example, via a heating coil and heats the bimetallic strip, which then bends.If the curvature is greater than the setting on the release, control contacts are activated or a circuit breaker's latch is released. The thermal release of the circuit breaker protects systems and equipment from overload, but not from short circuits. Electromagnetic releases, such as those with a coil, are used for this purpose. If a sufficiently large current flows through this coil, a striking armature is activated and, for example, releases a circuit breaker's latch without delay.

[0003] In conventional circuit breakers or protective switching devices, the creepage distances that must be maintained are correspondingly long due to, for example, the high operating voltage and the existing degree of pollution. The degree of pollution is determined by the device's own contamination, for example through the formation of a conductive plasma, such as soot or silver particles, during the shutdown process of short circuits and use in industrial environments. Creepage distances are formed when electrical current does not flow only along the intended conduction elements, such as the connection tracks, conductor tracks, copper surfaces and vias. Particularly at higher voltages, partial discharges can occur in which the insulation material orAn electric current flows through the air, with discharges occurring particularly in areas where inhomogeneities in the medium are subject to strong field influences, such as contamination. These impurities have a lower dielectric constant than the surrounding material, which increases the field strength. For example, it is conceivable that a creepage current, also known as leakage current, flows along the surface of an insulating material. This is due in particular to the fact that even if the internal insulating properties of an insulating material are determined by its specific electrical resistance, the current conduction at its surface can deviate considerably from this, even if the dielectric strength of an air gap of the same length has not yet been reached.

[0004] To prevent the occurrence of leakage currents, a minimum distance must be maintained between circuits and, in particular, current-carrying components. However, the space required for this is insufficient due to the compact design and the resulting limited space available for circuit breaker devices.

[0005] Furthermore, a further increase in clearance or creepage distances is required if, for example, reliable isolation between a high operating voltage and a voltage level at a user interface must be ensured. Particularly when short circuits occur and during the short-circuit shutdown function of the circuit breaker device, very high temperatures and pressures can arise, at least briefly, due to the resulting plasma.

[0006] EP 2 826 117 B1 relates to a device for protecting a consumer, wherein the device comprises a first current path comprising a first and a second line, and a monitoring device for detecting an impending overload of the electrical consumer. In order to provide a thermally and electrically optimized, improved, and cost-effective device with which an impending overload of a consumer can be detected, it is proposed that the monitoring device comprises a first temperature measuring unit, a carrier, an evaluation unit, and a first measuring transducer, which establishes an electrically conductive connection between the first and second lines of the first current path, wherein the first temperature measuring unit is galvanically isolated from the first measuring transducer and comprises a first temperature sensor.wherein an additional electrically insulating material is arranged on a first side surface of the carrier between the first measuring transducer and the carrier, and the first temperature sensor is arranged on the carrier in such a way that it can detect a temperature of the first measuring transducer, wherein the evaluation unit can determine an upcoming overload at the consumer by means of detected temperatures of the first temperature sensor.

[0007] In DE 10 2009 009 288 A1, the rigid-flexible carrier plate serves to attach at least one semiconductor light source and has at least one rigid carrier region for attaching the at least one semiconductor light source and a flexible carrier region, wherein the flexible carrier region is created by thinning a rigid carrier region. The lighting device is equipped with at least one rigid-flexible carrier plate, with at least one semiconductor light source mounted on at least one rigid-flexible carrier plate.

[0008] Accordingly, it is the object of the present invention to at least partially eliminate the disadvantages described above in a circuit breaker device or a protective switching device and, in particular, to provide a circuit breaker device in which the creepage distances can be minimized and the compact design of a circuit breaker device can be implemented in a simple and cost-effective manner.

[0009] The above object is achieved by a circuit breaker device for automatically switching off an electrical circuit when permissible current and / or voltage values ​​are exceeded, having the features according to claim 1. Further features and details of the invention emerge from the subclaims, the description and the drawings.

[0010] The circuit breaker device for automatically switching off an electrical circuit when permissible current and / or voltage values ​​are exceeded comprises at least one multilayer substrate for the mechanical arrangement and connection of electronic components, wherein the multilayer substrate comprises at least one carrier layer for attaching the electronic components to at least one surface of the carrier layer and at least one cover layer for covering the electronic components, wherein the carrier layer and the cover layer comprise a dielectric material and form a hermetically sealed housing. It is generally known that so-called printed circuits, for example, are used to attach and connect electrical or electronic components. These are flat structures made of a mostly electrically insulating material that is provided with thin-layer conductor tracks on one or both sides.Such printed circuits are also referred to as printed circuit boards or printed circuit boards. The multilayer substrate, which can also be referred to as a multilayer substrate and is advantageously an active multilayer substrate, has a sandwich structure in which a carrier layer for attaching the electronic components is at least partially surrounded by a cover layer for covering the electronic components. According to the invention, the electrical or electronic components are arranged on at least one surface of the carrier layer, such that the components are separated from the environment by the carrier layer, at least in a lower region. Furthermore, the multilayer substrate has a cover layer which advantageously completely covers or encases the remaining component surfaces, i.e., those surfaces not connected to the carrier layer.Accordingly, it is possible for the cover layer to contact the carrier layer, at least in sections, in those areas where no component is arranged on the carrier layer. The carrier layer and the cover layer consequently form a housing in which the electronic components are embedded. According to the invention, the electronic components are enclosed or encased by the carrier layer and the cover layer in such a way that they are hermetically sealed off from the environment, so that advantageously no dirt from the outside environment can penetrate into the areas of the components. Furthermore, the carrier layer and also the cover layer comprise a dielectric material which is electrically weak and, in particular, non-conductive. The dielectric material, which can be, for example, a gas, a liquid or even a solid, is advantageously a solid within the scope of the invention.

[0011] Advantageously, the required installation space is reduced by means of the circuit breaker device according to the invention and the multilayer substrate arranged within the circuit breaker device, while at the same time, due to the embedding of the electronic components within the multilayer substrate, the degree of contamination is reduced to a factor of 1. Contamination is understood here in particular to mean any foreign material in solid, liquid, or gaseous form that can impair the dielectric strength or surface resistance of an insulating material. While with a contamination degree of 4, the contamination leads to consistent conductivity, with a contamination degree of 1, there is no contamination or only dry, non-conductive contamination, so that the contamination no longer has any influence.Consequently, the circuit breaker device according to the invention, and in particular the multilayer substrate, advantageously prevents contamination of the electronic components, and in particular of the conductive areas between the electronic components. This allows the required creepage distances to be minimized accordingly, thus implementing a compact design for the circuit breaker device.

[0012] The electronic components embedded in the multilayer substrate, which are permanently mechanically shielded against environmental influences, are thus safely separated from one another by the cover layer, so that even a number of short-circuit shutdowns in the circuit breaker device no longer affect the creepage distances. Advantageously, this eliminates the need for air gaps between the individual electronic components. Furthermore, the electronic components are also adequately protected against condensation, especially in harsh operating conditions with temperatures between -25°C and 125°C. This means that the electronic components are adequately protected against moisture penetrating from outside. In particular, if a short-circuit shutdown of the circuit breaker device occurs, the electronic components are adequately protected from heat generation and pressure waves. Furthermore, the need for an additional housing is eliminated.

[0013] Within the scope of the invention, it is further possible for the multilayer substrate to have more than one carrier layer and one cover layer, and advantageously one carrier layer and two cover layers, or even more than two carrier layers and more than two cover layers. The carrier layers can therefore also form intermediate layers, which are interconnected to form a multilayer composite and are encased, for example, by a cover layer or two or more cover layers. The use of multiple carrier layers also advantageously increases the number of electronic components that can be arranged within the multilayer substrate while maintaining the same level of hermetic embedding of these components.

[0014] It is further conceivable for the electronic components to be arranged on two opposing surfaces of the carrier layer of the multilayer substrate. Accordingly, the carrier layer can be populated either on one or both sides. It is also possible for the multilayer substrate to have one or more carrier layers populated on one side and one or more carrier layers populated on both sides. Populating the carrier layer on both sides advantageously increases the number of electronic components on the multilayer substrate compared to populating the carrier layer on one side, with only a marginal increase in the thickness of the multilayer substrate.

[0015] In order to connect the individual electronic components to one another for transmitting electrical energy, it is conceivable for at least one conductor track to be arranged on at least one surface of the carrier layer of the multilayer substrate for electrically conductive connection between the electronic components. Such conductor tracks are thus also embedded between the at least one carrier layer and the at least one cover layer, so that these conductor tracks no longer need to be soldered to a plate of a printed circuit board, which can advantageously reduce the exposure to the harmful gas generated during soldering, for example, in an industrial or manufacturing environment.

[0016] It is further conceivable for at least one connection element for connecting the multilayer substrate to at least one electrical, electronic, or electromechanical component to extend at least partially out of the multilayer substrate. Such a connection element, such as a plug or connector, therefore has a region that is arranged, in particular, between the carrier layer and the cover layer and is at least partially encased by the cover layer in such a way that, even via the region of the connection element located outside the multilayer substrate, no contamination can penetrate into the interior of the multilayer substrate, and in particular into the region of the electronic components and the conductor tracks between the electronic components.

[0017] Within the scope of the invention, it is further possible for at least the carrier layer of the multilayer substrate to comprise an epoxy resin. Consequently, it is also conceivable for the cover layer, or only the cover layer, to comprise an epoxy resin in addition to the carrier layer. Epoxy resins, also known as reactive resins, are curable synthetic resins that can be converted into a thermosetting plastic with a hardener and, if necessary, additives.

[0018] It is therefore possible for at least the cover layer of the multilayer substrate to be a continuous fiber-reinforced thermoset semi-finished product. It is also conceivable for the carrier layer, or only the carrier layer, to be a continuous fiber-reinforced thermoset semi-finished product in addition to the cover layer. Advantageously, the semi-finished product, which can also be referred to as a prepreg, comprises a curable synthetic resin, such as the epoxy resin mentioned above. The machine-processable prepregs are characterized by a high fiber volume fraction and low undulation. In a prepreg, which is, for example, a glass fiber fabric impregnated with epoxy resin, the resin is in an intermediate stage where the resin is not yet fully cured. The resin cures during a pressing process in which the prepreg is pressed with another layer to form a composite. This pressing process advantageously takes place at a temperature above the glass transition temperature of the epoxy resin. For example, it is conceivable for the multilayer substrate to consist of at least one and in particular two prepregs, which are pressed together at a temperature of, for example, 150°C.A pressing temperature must be considered at which pressing and thus final curing of the prepreg resin can be ensured, while simultaneously avoiding damage to the electronic components due to the increased heat input. It is advantageous to press the carrier layer to the cover layer, and thus press the electronic components between the carrier layer and the cover layer, in a vacuum press.

[0019] It is also conceivable that the prepregs or cover layer used could be provided with cavities in the area of ​​the electronic components to ensure complete filling of the created cavities, even beneath the individual electronic components. This is particularly necessary to ensure complete encapsulation of the electronic components.

[0020] The final thickness of the multilayer substrate essentially results from the thickness of the integrated electronic components, so that, for example, with a component height of 0.5 mm, the multilayer substrate thickness can be, for example, 5 mm. Advantageously, the circuit breaker device according to the invention using the multilayer substrate reduces the stress on the electronic components caused by vibrations and shocks. Furthermore, the electronic components embedded between the carrier layer and the cover layer are adequately protected against mechanical damage, which can occur, for example, due to handling of the multilayer substrate during installation in the circuit breaker device, for example, due to very tight space conditions.Furthermore, reverse engineering is advantageously made more difficult, as the electronic components are firmly embedded between the carrier layer and the cover layer, thus being arranged under a solid shield and thus no longer directly accessible from the outside. The tracking resistance of the multilayer substrate advantageously has a CTI (Comparative Tracking Index) value of over 400. The CTI value indicates the voltage up to which the base material exhibits no tracking, particularly when 50 drops of standardized electrolyte solution are applied.

[0021] A circuit breaker device according to the invention and the multilayer substrate arranged in the circuit breaker device are explained in more detail below with reference to the drawings. They show schematically: Fig. 1 a plan view of an embodiment of a multilayer substrate, Fig. 2 a view of a along the in the Fig. 1 shown section line AA executed cut of the multilayer substrate, and Fig. 3 a perspective view of an embodiment of a circuit breaker device according to the invention, comprising a multilayer substrate.

[0022] Elements with the same function and mode of action are listed in the Fig. 1 to 3 are each provided with the same reference numerals.

[0023] In the Fig. Figure 1 shows a plan view of an embodiment of a multilayer substrate 1 and in particular of a cover layer 3 of the multilayer substrate 1. The electronic components not shown here are completely covered by the cover layer 3, wherein the cover layer 3 forms a flat surface. Connection elements 4 extend according to the Fig. 1 at least partially from the multilayer substrate 1 in the direction of the environment U. These connection elements 4 serve to connect the multilayer substrate 1 and in particular the electronic components of the multilayer substrate 1 with corresponding assemblies or component components of the Fig. 3 shown circuit breaker device.

[0024] In the Fig. Figure 2 is a schematic view of a section of the multilayer substrate 1 along the Fig. 1. The multilayer substrate 1 has a carrier layer 2 and a cover layer 3 arranged above the carrier layer, wherein the carrier layer 2 and the cover layer 3 are arranged next to one another in a connection zone 5. The electronic components 6 are arranged at least partially between the carrier layer 2 and the cover layer 3 and are consequently completely encased in a housing formed from the carrier layer 2 and the cover layer 3. The housing formed by the carrier layer 2 and the cover layer 3 advantageously hermetically encapsulates the electronic components 6 from the external environment. Between two electronic components 6, a conductor track is indicated by the reference numeral 7, which conductor track in particular enables an electrically conductive connection between these components 6.

[0025] In the Fig.Figure 3 further schematically shows an embodiment of a circuit breaker device 10 according to the invention, which has a multilayer substrate 1. Advantageously, the circuit breaker device 10 shown is a molded case circuit breaker (MCCB). List of reference symbols 1 multilayer substrate 2 Carrier layer 2a Surface of the carrier layer 3 Top layer 4 connecting element 5 Connection zone 6 electronic component 7 Conductor track U environment

Claims

[1] Circuit breaker device (10) for automatically switching off an electrical circuit when permissible current and / or voltage values ​​are exceeded, comprising a multi-layer substrate (1) for the mechanical arrangement and connection of electronic components (6), wherein the multi-layer substrate (1) has at least one carrier layer (2) for attaching the electronic components (6) to at least one surface (2a) of the carrier layer (2) and at least one cover layer (3) for covering the electronic components (6), wherein the carrier layer (2) and the cover layer (3) have a dielectric material and form a hermetically sealed housing. [2] Circuit breaker device (10) according to claim 1, characterized by that the electronic components (6) are arranged on two opposite surfaces of the carrier layer (2) of the multilayer substrate (1). [3] Circuit breaker device (10) according to one of claims 1 or 2, characterized by that at least one conductor track (7) is arranged on at least one surface (2a) of the carrier layer (2) of the multi-layer substrate (1) for the electrically conductive connection between the electronic components (6). [4] Circuit breaker device (10) according to one of the preceding claims, characterized by that at least one connection element (4) for connecting the multi-layer substrate (1) to at least one electrical or electronic or electromechanical component extends at least partially out of the multi-layer substrate (1). [5] Circuit breaker device (10) according to one of the preceding claims, characterized by that at least the carrier layer (2) of the multilayer substrate (1) comprises an epoxy resin. [6] Circuit breaker device (10) according to one of the preceding claims, characterized bythat at least the cover layer (3) of the multi-layer substrate (1) is a continuous fiber-reinforced thermosetting semi-finished product.

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