ESD-optimized control unit design concept

Abstract

Electronic circuit with an ESD protection device (100) for protecting an electronic component (200) from electrostatic discharge, comprising: a carrier material (110); a component (200) that is applied to the carrier material (110); an ESD protection device (100) which has a feedthrough (120, 130, 140) through the carrier material (110) which is arranged adjacent to the electronic component (200) and which allows the current generated by an electrostatic discharge to be diverted directly through the feedthrough (120, 130, 140) through the carrier material (110) to a ground return in order to prevent the current from being diverted through the component (200), where the feedthrough (120) is a hole which is not filled, where the ground return is a base plate, a conductive support, or a housing.

Description

The invention relates to an electronic circuit having an ESD protection device, to a control device, to a motor vehicle having a control device, and to a method for producing an electronic circuit having an ESD protection device.Electrostatic discharges, in particular in connection with semiconductor components, are referred to by the abbreviation ESD (electrostatic discharge). Owing to the low energy, such electrostatic discharges are harmless to humans, but the electronic semiconductor components installed in control units can be susceptible to this.In this case, basically two different ESD events must be taken into account:ESD discharges are delivered directly to a metallic conductor (in reality, by e.g. the finger of an engineer, in the ESD test by previously touching the conductor with the ESD gun and then delivering the ESD charge).ESD discharges are emitted by the air ("lightning") onto the ladder (reality: loaded finger of an engineer approaches a ladder until the rollover takes place; ESD test: loaded gun approaches the ladder until the rollover)Both events have different limit values for the maximum voltages to be exceeded (usually e.g. direct discharge e.g. max. 8 kV, e.g. air discharge max. 15kV).Therefore, it is very important to develop improved ESD protection design concepts that can also cover increased customer requirements from, for example, 8 kV to 18 kV discharges.US 2016 / 0 293 554 A1 discloses a method for producing an electrical protection structure for signal isolation. The protection structure comprises wall-like electrically conductive protrusions on a substrate which, in use, are electrically grounded to ensure signal isolation.U.S. Pat. No. 498 7100 A discloses packaging of an electronic device with a thin, flexible conductor foil as component carrier.US 2012 / 0 299 165 A1 discloses a semiconductor component which comprises a semiconductor chip which is attached to a substrate and an encapsulation material which is applied over the chip and the substrate. A shielding layer is formed over the encapsulant.US 2014 / 0 340 859 A1 discloses a substrate with circuits for two or more modules on the substrate. Component portions of the modules are shielded by a metallic structure on or in the substrate.US 2006 / 0 087 821 A1 discloses a printed circuit board having an electrical conductor for absorbing an electrostatic charge.US 2010 / 0 142 111 A1 discloses an electronic device having a printed circuit board which is accommodated in a housing. The printed circuit board includes a substrate, a ground layer on the substrate, a discharge conducting portion exposed on an outer surface of the circuit board to provide an antistatic structure, and a plurality of vias extending through the substrate. The discharge conducting portion and the ground layer are electrically connected to each other by at least two of the vias.DE 10 2010 040 558 A1 discloses a control device, in particular for a motor vehicle. The controller includes a circuit board, a high impedance circuit part disposed on the circuit board and having an impedance of 1 kΩ or higher with respect to a ground of the controller, and at least one conductive protection element electrically connected to the ground. The protection element is arranged next to the high-impedance circuit part on the printed circuit board and has a height within a protection distance from the high-impedance circuit part which is at least equal to the protection distance.It is the object of the invention to reduce the probability of failure of a control device.This object is achieved by the features of the independent claims. Further developments of the invention are evident from the dependent claims and the following description of embodiments.A first aspect of the invention relates to an electronic circuit having an ESD protection device for protecting an electronic component from an electrostatic discharge, comprising: a carrier material, a component which is applied to the carrier material, an ESD protection device which has a feedthrough through the carrier material, which feedthrough is arranged adjacent to the electronic component and allows the current generated by an electrostatic discharge to be discharged, directly through the feedthrough through the carrier material, to a ground return in order to prevent the current from being discharged through the component. The feedthrough is a hole which is not filled and the ground return is a base plate, a conductive mount or a housing.The ESD protection device according to the present invention may provide that a component on a carrier material is protected from electrostatic discharges. ESD damage can arise essentially as a result of the briefly high current from the ESD voltage source through a sensitive component (semiconductor) to the ground or greater electrical capacitance in the control device. This is usually a metallic base plate or the housing. In a test case, this base plate can be connected to a return conductor of the ESD gun. Firstly, electrostatic discharges can be suppressed by protecting the wiring conductor guides via corresponding plastic geometries in such a way that direct contact or approach of a charged body is made impossible (for example by tight covers, plastic spacer rings around stamped grid conductors, and the like).Essentially, the following can be achieved with this:Conductor guides cannot be directly touched by persons (direct discharge).The structural configuration can have a sufficiently large minimum distance between the conductors and the charged bodies.In order to achieve high ESD protection up to high voltages, it may be necessary to have no externally exposed wiring conductors on the control device. This can be achieved, for example, by using flexible conductor foils, covers / covers which are designed to be tight (welded / laminated).Already present electrically conductive geometries of the control device can be used as "lightning arresters" for the ESD lightning in order to conduct the discharge current past the sensitive components directly into the ground return conductor. The ground return line can be, for example, the base plate of the circuit, a metallic holder or the housing of a control unit. The ESD protection device can be realized by means of feedthroughs in the carrier material in the vicinity of the electronic component to be protected. The carrier material with the electronic component can be guided over the ground return conductor or the electronic component can be fastened on the ground return conductor. In the event of a terminating electrostatic charge occurring, the current occurring can be conducted directly from the source of the electrostatic discharge into the ground return, through the carrier material. As a result, the electronic component to be protected is not affected by an electrostatic final charge. That is, a large current is not conducted into the electronic component and the electronic component is not damaged.The ground return lines can be, inter alia, carrier plates made of aluminum, steel or printed circuit board material printed with conductor tracks serving for stiffening purposes. Care should be taken that an approaching electrically charged body discharges into a ground conductor (e.g., ground plate or ring-shaped open ground conductor trace around a sensitive device) rather than into a signal line to be protected that is connected to a sensitive electronic device.There may be a case where ESD-damaged components temporarily maintain their full function. The failure of the components can subsequently occur in an uncertain period of time, since the components damaged by ESD are no longer suitable for permanent loading.For the ESD protection device according to the present invention, no additional components need to be installed in the control unit. The components that are present in any case can be designed geometrically differently. This makes it possible to avoid additional costs and effort during production. For this purpose, a feedthrough or a plurality of feedthroughs is introduced into the carrier material of the electronic component to be protected. The feedthroughs should be arranged adjacent to the electronic component to be protected. The substrate with the feedthroughs and the electronic component may be disposed over a ground return, e.g., a conductive base plate or the housing. In the case of an electrostatic discharge, the current can be conducted into the ground feedback via the feedthrough, so that no high currents are introduced into the electronic component.The electronic components to be protected can thus be removed from the direct discharge path of the electrostatic discharge and thereby protected.The increasing ESD requirements in the development of control units can thus be taken into account.The feedthroughs used in the carrier material can have a variety of different forms. The feedthroughs can be circular holes in the carrier material, but can also be rectangular, triangular, hexagonal, semi-circular or any other shape. Furthermore, the feedthroughs can also be grooves which are arranged around the component to be protected.According to an example, the feedthrough comprises a conductive via.The ESD protection device can also provide an electrical plated-through hole in addition to a feedthrough for the electrostatic discharge, i.e. a hole. That is to say that the carrier material is broken through by an electrical conductor, such that the electrical conductor extends from the upper side to the lower side of the carrier material. By means of this arrangement, the electrostatic discharge arriving on the upper side of the carrier material can be passed on directly to the ground return conductor. Thus, the passages can be formed with small diameters. Furthermore, the vias may make it possible to equip thicker layers, such as printed circuit boards, with the ESD protection device and to protect it effectively.A further example provides that the conductive through-connection has an elevation, for example in the form of a tip, out of the plane of the carrier material.The electrostatic discharge current can be given an attack point by the tip, so that the flash of the discharge is "attracted" by the metallized tip and is introduced directly into the ground return.One embodiment of the invention provides that a plurality of feedthroughs are provided in the carrier material, adjacent to the electronic component.For ESD protection of an electronic component, a multiplicity of feedthroughs can be provided in the carrier material. Here, the feedthroughs may be holes, metal feedthroughs, or metal feedthroughs with tips. The individual feedthroughs can be arranged adjacent to the component to be protected in order to ensure the best possible ESD protection. The different types of feedthroughs may also be combined in an ESD protection device in order to combine the advantages of the individual types of feedthroughs.One embodiment of the invention provides that the feedthroughs are arranged equidistantly from one another.The feedthroughs in the carrier material may have the same distance from one another. A regular pattern can thus be produced and sufficient capacitance remains in the carrier material to integrate electrical lines. It should be pointed out at this point that the multiplicity of feedthroughs can also have different distances from one another. In particular, particularly sensitive or important parts can thus be provided with a more intensive ESD protection by arranging more feedthroughs or the feedthroughs closer together and closer to the electronic component to be protected.A further embodiment of the invention provides that the feedthroughs are arranged equidistantly with respect to the electronic component to be protected.In addition to an equidistant arrangement of the feedthroughs among one another, the feedthroughs may also all have a constant distance from the electronic component to be protected. This makes it possible to achieve a geometry which protects all sides of the component to be protected to the same extent. Here, too, it should be pointed out that the feedthroughs can have different distances from the electronic component. In particular in the region with many electrical leads to the electronic component, a plurality of feedthroughs for ESD protection can be provided, so that these are particularly protected in order thus to prevent an increased current in the lead to the electronic component and thus damage to the electronic component.One embodiment of the invention provides that the feedthroughs are arranged completely or partially around the electronic component to be protected.For ESD protection of an electronic component of different angles of attack, the feedthroughs can be arranged around the electronic component to be protected. Here too, the feedthroughs can be arranged equidistantly to one another and / or equidistantly to the component to be protected.One embodiment of the invention provides that a feedthrough is arranged equidistantly with respect to two electronic components.In addition to the equidistant distribution of the feedthroughs among one another and the equidistant distribution of the feedthroughs to the electronic component to be protected, a feedthrough can also be arranged equidistant to two electronic components to be protected, i.e. the feedthrough is located between two components and can simultaneously protect both components from an electrostatic discharge.According to a further embodiment of the invention, the distances between the component to be protected and the feedthroughs can be different or freely varied. The distances can be adapted depending on the component to be protected and the risk potential at this location, so that it is possible to react to various scenarios.One embodiment of the invention provides that the carrier material is a flexible conductive film.In order to be able to adapt the carrier material to the ground return or the printed circuit board, the carrier material can be a flexible conductor foil. This can be easily adapted to the surface of the respective ground return, regardless of whether this is a base plate, a conductive holder or a housing.A further aspect of the invention relates to a control device having an electrical circuit described above and below for protecting electronic components from electrostatic discharge.A further aspect of the invention relates to a vehicle having a control unit described above and below.The term vehicle is not limited to a car alone, but also includes trucks, buses, tractors, tanks, construction machinery, rail vehicles, ships, aircraft such as helicopters or aircraft, bicycles and bicycles.A further aspect of the invention relates to a method for producing an electrical circuit for protecting electronic components from electrostatic discharge. In this case, a feedthrough is produced through a carrier material which is arranged adjacent to the electronic component to be protected and enables the current produced by an electrostatic discharge to be discharged directly through the feedthrough through the carrier material to a ground feedback in order to prevent the current from being discharged through the component. The feedthrough is a hole which is not filled and the ground return is a base plate, a conductive mount or a housing.The method can provide that at least one feedthrough, e.g. a hole or a through-connection, is introduced into a carrier material, so that an electrostatic discharge is conducted through the feedthrough, through the carrier material, to a ground return. As a result, the electronic components can be protected from overvoltage damage due to electrostatic discharges.Further features, advantages and possible applications of the invention are evident from the following description of the embodiments and figures. The figures are schematic and not to scale. If the same reference numerals are given in different figures in the following description, these denote the same or similar elements. FIG. 1 shows a schematic illustration of an ESD protection device with a feedthrough according to one embodiment of the invention. FIG. 2 shows a schematic illustration of an ESD protection device with a metallized feedthrough, according to an example. FIG. 3 shows a schematic illustration of an ESD protection device with a metallized feedthrough having a tip, according to an example. FIG. 4 shows a schematic illustration of an ESD protection device having a feedthrough adjacent to an electronic component, according to an embodiment of the invention. FIG. 5 shows a schematic illustration of an ESD protection device having a feedthrough adjacent to an electronic component, according to an embodiment of the invention. FIG. 6 shows a schematic illustration of a vehicle having a control unit with an ESD protection device according to one specific embodiment of the present invention.FIG. 1 shows a schematic illustration of an ESD protection device 100. This comprises a carrier material 110 and a feedthrough 120, which is arranged adjacent to an electronic component 200. The electronic component 200 is connected to the carrier material 110 and the electrical leads for the electronic component 200 can run in the carrier material 110. The substrate 110 with the feedthrough 120 may be disposed over a ground return conductor. By this arrangement, an electrostatic discharge can discharge directly into the ground return line without striking the substrate 110 and damaging the electronic component 200 thereon.FIG. 2 shows a metallized feedthrough 130 through the carrier material 110. As a result of the metallization, the current can be conducted better by the electrostatic discharge from the upper side of the carrier material 110, through the carrier material 110 and subsequently into the ground return. In addition to better conduction of the current through the carrier material 110, the electrostatic discharges are attracted by the metallization. Thus, a better ESD protection for the electronic components 200 and thus for the entire electrical circuit may be ensured by the ESD protection device 100.FIG. 3 shows a metallized feedthrough 140 having a tip formed upwardly out of plane. The tip is applied to the metallized feedthrough 140 in order to reduce the distance between the metallized feedthrough 140 and the object from which the electrostatic discharge originates. An object from which an electrostatic discharge is generated can be, for example, a finger of a human who mounts or repairs the electrical circuit or a tool for repair. On the other hand, the metallized feedthrough 140 with tip offers an active point of application for the current.FIG. 4 shows an electrical circuit with an ESD protection device 100 mounted over a mount. The holder may be made of metal and is grounded in this case. Thus, the holder represents the mass return. In FIG. 4, the carrier material 110 consists of a flexible film in which the supply lines for the electronic component 200 are also integrated. The feedthroughs 120 are designed as circular holes in FIG. 4 and are arranged around the component 200 to be protected. The distances between the individual feedthroughs 120 are identical, and the distance between the individual feedthroughs 120 and the component 200 to be protected is also embodied to be constant. Furthermore, FIG. 4 shows that a feedthrough 120 is suitable for protecting two electronic components 200 by the feedthrough 120 being arranged between two electronic components 200 to be protected. Ideally, in this case, the feedthrough 120 is arranged in such a way that the distance from both electronic components 200 is the same.FIG. 5 shows an electrical circuit with an ESD protection device 100 in a further embodiment. Here, the carrier material 110 is designed as a flexible film and this is arranged around the mass return. The feedthroughs 120 are arranged close to the electronic component 200 to be protected, so that effective protection against electrostatic discharges is possible. The electrostatic discharge thus takes place through the feedthrough 120 of the carrier material 110 and is fed back via the ground return, so that no high electrical loads arise for the component 200 to be protected. Thus, by the ESD protection device 100 according to the present invention, an electric circuit can be prevented from damage caused by electrostatic discharges.FIG. 6 shows a vehicle 600 having a control unit 610, in which an electrical circuit having an ESD protection device 100 is installed.

Claims

An electronic circuit comprising an ESD protection device (100) for protecting an electronic component (200) from electrostatic discharge, comprising: a substrate (110); a component (200) deposited on the substrate (110); an ESD protection device (100) comprising a feedthrough (120, 130, 140) through the substrate (110), disposed adjacent to the electronic component (200), and enabling the electrostatic discharge generated current to be diverted directly through the feedthrough (120, 130, 140) through the substrate (110) to a ground return to prevent the current from being diverted through the component (200), wherein the feedthrough (120) is a hole that is not filled, wherein the ground return is a base plate, a conductive support or a housing.The electronic circuit of the preceding claim, wherein a plurality of feedthroughs (120, 130, 140) are provided in the substrate (110) adjacent to the electronic component (200).Electronic circuit according to Claim 2, wherein the feedthroughs (120, 130, 140) are arranged equidistantly from one another.Electronic circuit according to one of Claims 2 and 3, wherein the feedthroughs (120, 130, 140) are arranged equidistantly with respect to the electronic component (200) to be protected.Electronic circuit according to one of Claims 2 to 4, wherein the feedthroughs (120, 130, 140) are arranged completely or partially around the electronic component (200) to be protected.Electronic circuit according to one of the preceding claims, wherein the feedthrough (120, 130, 140) is arranged equidistantly with respect to two electronic components (200).Electronic circuit according to one of the preceding claims, wherein the carrier material (110) is a flexible conductive foil.Control device (610) having an electronic circuit according to one of Claims 1 to 7 for protecting electronic components (200) from electrostatic discharge.Vehicle (600) having a control device (610) according to Claim 8.Method for producing an electronic circuit for protecting electronic components from electrostatic discharge, comprising the following step: - creating (601) a feedthrough through a carrier material, which is arranged adjacent to the electronic component to be protected and allows the current generated by an electrostatic discharge to be discharged, directly through the feedthrough through the carrier material, onto a ground feedback in order to prevent the current from being discharged through the component, wherein the feedthrough (120) is a hole which is not filled, wherein the ground feedback is a base plate, a conductive holder or a housing.

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