COMPACT CONTROL FOR LIGHTING IN VEHICLES

Description

Field of invention

[0001] The invention relates to a method for manufacturing a device for controlling an LED lighting device.

[0002] The invention therefore relates to a method for manufacturing, for example, a control device for a lighting device with, for example, a CAN communication data bus interface, a computer core (microcontroller) and a driver circuit for one or more LED light sources. General Introduction

[0003] Normally, the bus driver modules of actuators and microcontrollers in a satellite / bus system for controlling devices, for example in motor vehicles, are designed as separate modules of a bus participant, typically arranged on a common circuit board. This is because very powerful computers are preferably required, which are then implemented in a semiconductor technology node with the smallest possible feature size. In contrast, the so-called bus transceivers, which represent the actual interface to the data buses, comprise power transistors whose feature sizes cannot be arbitrarily reduced for physical reasons, namely due to the required current-carrying capacity.This results in typically two different components (IC chips) in two semiconductor technologies, namely the bus transceivers and the drivers / LEDs (analog part), being manufactured separately from the powerful computers (digital part) and mounted on printed circuit boards.

[0004] For example, DE 20 2004 006 292 U1 discloses a lighting device with a control device having a DALI interface. The known control device has several modules, but it remains unclear what components the individual modules comprise.

[0005] A projection module is known from DE-A-10 2009 004 117.

[0006] LED light source control devices with circuit elements of interface, microcontroller and LED driver circuits integrated on a common chip are known from EP-A-3 478 031.

[0007] From EP-A-2 440 018 a compact light source control with the features of the preambles of claims 1 and 8 is known.

[0008] US-B-9 936 552 describes an LED driver with analog and digital circuit components. Object of the invention

[0009] The invention is therefore based on the objective of creating an optimal solution for the manufacture of LED drivers in automotive systems, which avoids the above disadvantages of the prior art and has further advantages. Solution to the task

[0010] To solve this problem, the invention proposes a method for manufacturing a device for controlling an LED lighting device, comprising the method steps of claim 1.

[0011] The invention proposes a manufacturing method for a control device for an LED lighting device, in which several electrical circuits are integrated into a common semiconductor substrate. These circuits include the data interface, the microcontroller, and the at least one LED driver. A key aspect of the invention is that the semiconductor technology to be used (and thus the smallest possible feature size of the circuit components) is determined by the minimum feature size permissible for the circuit components of the data interface and the at least one LED driver while ensuring their functionality.

[0012] The smallest "feature size" achievable in the fabrication of an integrated circuit using semiconductor technology, as is known in the trade, refers to the shortest edge length of a component (i.e., a feature size of a component) of a circuit component, typically meaning the shortest possible gate length of a field-effect transistor. In the invention, therefore, the shortest edge length of a component of a circuit component of the data interface and / or the LED driver circuit(s) is equal to the shortest edge length of a component of a circuit component of the microcontroller, namely the shortest gate length of a field-effect transistor or transistors of the microcontroller.

[0013] Unlike the prior art, the invention does not employ the semiconductor technology that would determine the minimum permissible feature sizes for the microcontroller's circuit components. As is known, microcontroller circuit components such as transistors and gates do not need to have the same current-carrying capacity as, for example, data interfaces and LED drivers. Therefore, the microcontroller's circuit components can be significantly smaller than the analog section of the overall circuit integrated into the semiconductor substrate. Typically, one would use this microcontroller-specific semiconductor technology to then fabricate larger circuit components for the data interface and the at least one LED driver.However, this is more expensive overall because the semiconductor technology, which allows for a higher density of circuit components, is more complex to implement.

[0014] The invention thus deviates from the previously known concept of IC chip design, which, as will be described below, is associated with significant technical and economic advantages. Semiconductor technologies particularly suitable are those whose smallest possible feature size is larger than, in particular, 85 nm and smaller than, in particular, 200 nm. All values ​​within the aforementioned range for the smallest possible feature size of the semiconductor technology to be used are hereby covered by the application.

[0015] In a preferred embodiment, the device produced according to the invention can be provided with a voltage regulator comprising circuit elements integrated into the semiconductor substrate. The semiconductor technology used is determined by the minimum feature size permissible for the circuit elements of the data interface, the LED driver circuit(s), and the voltage regulator to ensure their functionality. Thus, the semiconductor substrate includes an additional component, the voltage regulator, which is designed as an analog circuit and consequently also comprises, for example, power transistors and wider conductor tracks.

[0016] In a further advantageous embodiment, the device produced according to the invention may be provided with a test interface comprising electronic and / or electrical circuit elements integrated into the semiconductor substrate for testing the functionality of the data interface and / or the microcontroller and / or the LED driver circuit(s) and / or the voltage regulator, if present. The semiconductor technology used is determined by the minimum feature size permissible for the circuit elements of the data interface, the LED driver circuit(s), the voltage regulator, and the test interface to ensure their functionality. This may, for example, involve a boundary scan test or tests that specifically address and test certain components of the semiconductor IC.

[0017] In a further advantageous embodiment, it may be beneficial if the device produced according to the invention has a sensor interface integrated into the semiconductor substrate, comprising electrical and / or electronic circuit elements, for connecting at least one sensor, such as a light brightness sensor and / or a light color sensor and / or a sun sensor, which is or can be connected to a data communication bus that can be connected to the sensor interface. The semiconductor technology used is determined by the minimum feature size that is still permissible for the circuit elements of the data interface, the LED driver circuit(s), the voltage regulator, the test interface, and the sensor interface to ensure their functionality. Such a sensor interface may, for example, be one conforming to the PSI5 or PSI3 protocol.

[0018] In a further advantageous embodiment of the invention, the microcontroller may only have the functionality required to control the LED driver circuit(s) according to signals received from the data interface and / or from the sensor interface, if present, and to process signals received from the test interface, if present. By reducing the microcontroller's performance, the space required for its gates, transistors, and other circuit elements and traces can be reduced, which is particularly advantageous given that the microcontroller does not use the semiconductor technology that provides the smallest possible feature size permissible for digital components.

[0019] The circuit elements whose functionality must be ensured during manufacturing using the semiconductor technology employed may be transistors and / or conductive traces.

[0020] The invention allows the production of an LED lighting device equipped with an LED light source comprising an LED or a series circuit of LEDs or a group of different colored LEDs or a series circuit of groups of different colored LEDs, wherein the LED light source is electrically connected to the output of a device according to one of the preceding claims.

[0021] An advantage of the method according to the invention is that the device has a voltage regulator with circuit elements that are integrated into the semiconductor substrate, the semiconductor technology used being determined by the minimum feature size that is still permissible for the circuit elements of the data interface, the LED driver circuit or LED driver circuits and the voltage regulator to ensure their functionality.

[0022] A further advantageous embodiment of the method according to the invention may provide that the device has a test interface integrated into the semiconductor substrate comprising electronic and / or electrical circuit elements for testing the functionality of the data interface and / or the microcontroller and / or the LED driver circuit or LED driver circuits and / or the voltage regulator, if present, wherein the semiconductor technology used is determined by the minimum feature size that is still permissible for the circuit elements of the data interface, the LED driver circuit or LED driver circuits, the voltage regulator and the test interface to ensure their functionality.

[0023] A further advantageous embodiment of the method may include the control device having a sensor interface integrated into the semiconductor substrate with electrical and / or electronic circuit elements for connecting at least one sensor, such as a light brightness and / or a light color sensor and / or a sun sensor, which is or can be connected to a data communication bus that can be connected to the sensor interface, wherein the semiconductor technology used is determined by the minimum feature size that is still permissible for the circuit elements of the data interface, the LED driver circuit or circuits, the voltage regulator, the test interface and the sensor interface (PSI5, PSI3) to ensure their functionality.

[0024] It is advantageous if the microcontroller is only provided with functionality that is required to control the LED driver circuit(s) according to signals received from the data interface and / or signals received from the sensor interface, if present, and is required to process signals received from the test interface, if present.

[0025] It is advisable to use a semiconductor technology with the smallest possible feature size, which is larger than 85nm or larger than 90nm or larger than 100nm or larger than 110nm or larger than 120nm or larger than 130nm or larger than 140nm or larger than 150nm or larger than 160nm or larger than 170nm or larger than 180nm or larger than 190nm.

[0026] Furthermore, it is advantageous to use a semiconductor technology with the smallest possible feature size, which is smaller than 200nm or smaller than 190nm or smaller than 180nm or smaller than 170nm or smaller than 160nm or smaller than 150nm or smaller than 140nm or smaller than 130nm or smaller than 120nm or smaller than 110nm or smaller than 100nm or smaller than 90nm or smaller than 85nm.

[0027] The invention represents a departure from previously typical, established technical approaches and developments, namely by co-integrating LED drivers, transceivers and microcontrollers on a semiconductor substrate without loss of computing power required for the application.

[0028] The inventive proposal increases the usability of the control device because, firstly, the chip area is reduced and, secondly, the assembly effort during the implementation of the control device is lowered. In technical circles, the computing power of the microcontroller would not be reduced in favor of the inventive co-integration, as this would limit the software design possibilities of the control device, which is contrary to the professional goal of providing new systems with better computing performance.

[0029] The device produced according to the invention is primarily intended for use in vehicles and thus in mass-produced goods. Especially with mass-produced goods, even the smallest advancements can have a significant impact and lead to the recognition of an invention. The invention substantially simplifies production, manufacturing, and technical application, and consequently offers considerable economic advantages, which in this case forms the basis for its recognition as an invention.

[0030] The reduced computing power of the microcontroller, as envisioned by the invention, is offset by the overriding technical advantage of simplification and the resulting increased cost-effectiveness. Thus, the reduction in the microcontroller's computing performance, through co-integration as described above, leads to a technically improved solution. This contradicts the efforts of the technical community, where it is known that, according to Mour's Law, the complexity of integrated circuits regularly doubles with minimal component costs. Gordon Mour defines complexity as the number of circuit components on an integrated circuit. Sometimes, this is also referred to as a doubling of the integration density, i.e., the number of transistors per unit area. As is well known, this technical development forms a crucial basis of the "digital revolution."Therefore, if the scientific community strives to utilize this ever-doubling integration density, the inventive idea clearly runs counter to this endeavor, namely to select the semiconductor technology based on the smallest possible feature size of the circuit components of the data interface (transceiver) and the LED drivers, as well as possibly other analog parts of the circuit, and not based on the smallest possible feature sizes for the digital part (microcontroller).

[0031] In principle, when designing semiconductor ICs with digital and analog sections, the aim is to use the semiconductor technology whose smallest possible feature size is best suited to the needs, requirements, and characteristics of the digital section. The transistors and gates of the digital section of a semiconductor IC are significantly smaller than the transistors of the analog sections, which usually need to be implemented as power transistors with a corresponding current-carrying capacity. With regard to semiconductor technology, one is always on the safe side if the technology selected is based on its ability to provide the smallest possible feature sizes for the digital section. This then allows the larger circuit elements of the analog section to also be manufactured using this semiconductor technology.

[0032] The smaller the smallest possible feature size of the semiconductor technology used, the more complex and expensive its implementation becomes. This invention therefore takes a different approach. The starting point for selecting the semiconductor technology is no longer the smallest permissible feature size for the digital part of the circuit, but rather the minimum feature size that ensures the functionality of the analog part. This means that the gates and transistors of the digital part now occupy larger chip areas. This increased chip area can be at least partially compensated for by reducing the computing performance to what is required for the application.This may mean that the chip area required for the digital part is larger compared to using a semiconductor technology with higher integration density, but this leads to an overall economic advantage, since a simpler and less complex semiconductor technology is used, whose integration density is lower because it is designed for analog parts.

[0033] For the reasons mentioned above, one can accept the reduction in the computing performance of the microcontroller with the advantage of co-integrating all circuit elements in a semiconductor technology whose smallest possible feature size is certainly larger than that of semiconductor technologies for the realization of digital parts, but this leads to an advantage again due to the lower costs when using such a comparatively "coarse" semiconductor technology.

[0034] It was thus recognized according to the invention that, in contrast to the common integration strategies described above, where the driver transistors of light source drivers cannot be arbitrarily miniaturized when combined with them, a surprisingly significant cost advantage arises from full integration in the technology node with the larger feature size, even though this increases the chip area for the microcontroller. This combination of technical features results in a surprising reduction in technical effort and, consequently, a significant economic advantage.

[0035] There was a prevailing technical prejudice in the professional community that co-integration of lighting drivers, computer system (microcontroller) and data bus interface would lead to a significant increase in the required chip area and thus to a considerably higher cost; because this would result in the computer system being produced using semiconductor technology, which, due to the larger minimum achievable feature size of the switching circuit components, would also lead to an increase in the chip area requirement of the computer system for digital circuits and gates of microcontrollers.The solution presented here, combining a known data bus interface with a known computer system and several known LED drivers, yields a surprising effect, even for experts: the total required chip area does not increase to such an extent through co-integration on a common semiconductor substrate that this increase in the computer system's chip area, beyond a certain number of LED drivers, is not offset by the savings in bond wires, bond pad areas, and packages. This unexpected synergy effect, resulting from the simplification of the system architecture through the use of a single semiconductor technology for manufacturing the integrated circuit elements, far outweighs the anticipated overall effect of the increased chip area of ​​the computer system.Neither in the products available on the market nor in patent literature or in scientific or other technical literature is there any reference to the solution according to the invention, since the experts would avoid an increase in the chip area of ​​the computer system; for them, it represents a paradigm shift if the computer system, as proposed according to the invention, is not realized in a semiconductor technology with the smallest possible feature size.

[0036] Another advantage of the invention is that the control of light sources, in particular light-emitting diodes, requires only a limited amount of computing power from the computer system, so that a special performance of the computer system is not required.Within the scope of the invention, it was recognized that, as a result, compromises can also be made regarding the bit width of the ALU (and / or CPU) of the computer system and the computing power of the computer system, such that by implementing the computer system using the technology of the data bus interface and the light source drivers, the chip area required by the computer system increases and the achievable computing power of the computer system decreases due to the increased area required for the conductor tracks within the computer system (with the same chip area available to the computer system), but on the other hand, the computing power associated with the otherwise increasing chip area of ​​the computer system for controlling the light sources and for operating the data bus interface is not required at all, which is surprising to those skilled in the art.

[0037] The effort required for a system can be estimated as follows, based on the current state of the art:

[0038] The meaning of the parameter names is as follows: K DBDB: Technical hardware effort of the interface to the data bus in the data bus interface, including, for example, bond pads, housing connectors, etc.; K DB: Technical hardware effort of the interface that is independent of the integration form; K GDBRS: Technical hardware effort of the interface between the data bus interface and the computer system on the data bus interface side, including, for example, bond pads, housing connectors of the data bus interface, etc.; K TDB: Semiconductor technology-specific, monetary cost factor for the realization of the hardware effort of the data bus interface; K GRSDB: Technical hardware effort of the interface between the data bus interface and the computer system on the computer system side, including, for example, bond pads, housing connectors of the computer system, etc.; K RS technical hardware effort of the computer system, which is independent of the integration form; K GRSLEDD technical hardware effort of the interface between the computer system and the n LED light source drivers on the computer system side, including, for example, bond pads, housing connectors of the computer system, etc.; K TRS semiconductor technology specific, monetary cost factor for the realization of the hardware effort of the computer system; K GLEDDRS technical hardware effort of the interface between the computer system and a driver for a light source on the driver side for the light source, including, for example, bond pads, housing connectors of the driver for the light source, etc.; K LEDD technical hardware effort of the driver for the light source, which is independent of the integration form; K GLEDLEDD technical hardware effort of the interface between the driver for the light source and the light source that the driver supplies with electrical energy, on the driver side, including, for example, bond pads, housing connections of the driver for the light source, etc.; K TDB semiconductor technology specific, monetary cost factor for the realization of the hardware effort of the driver for the light source; n LED number of light sources or groups of light sources and thus number of drivers for light sources in the overall system; K gd economic effort for the overall system with discrete components; .

[0039] For example, the overall system components whose chip area is dominated by power drivers, which would be the case for the data bus and / or test interface and / or sensor interface and the light source drivers as well as for a voltage regulator, if present, could be manufactured in a first technology on a first semiconductor substrate (IC chip) in a first semiconductor technology with a first feature size, while the computer system, which mainly has small digital transistors, could be manufactured on a second semiconductor substrate (IC chip) in a second semiconductor technology with a second feature size, where the second feature size is smaller than the first feature size. K gLEDDDS economic expenditure for a system in which only the computer system is implemented separately from the data bus interface and the drivers for the light sources;

[0040] This economic expense is then calculated as follows: K gLEDDDS = K TDB * K DBDB + K DB + K GDBRS + n LED * K GLEDDRS + K LEDD + K GLEDDLED + K TRS * K GRSDB + K RS + K GRSLEDD .

[0041] We are now looking for: K gd > K gLEDDDS

[0042] This corresponds to: K TDB * K DBDB + K DB + K GDBRS + K TRS * K GRSDB + K RS + K GRSLEDD + n LED * K TLEDD * K GLEDDRS + K LEDD + K GLEDDLED < K TDB * K DBDB + K DB + K GDBRS + n LED * K GLEDDRS + K LEDD + K GLEDDLED + K TRS * K GRSDB + K RS + K GRSLEDD

[0043] This is equivalent to: K TDB * K DBDB + K DB + K GDBRS + n LED * K TLEDD * K GLEDDRS + K LEDD + K GLEDDLED < K TDB * K DBDB + K DB + K GDBRS + n LED * K GLEDDRS + K LEDD + K GLEDDLED

[0044] For K TLEDD = K TDB, there is no significant difference, which can also be observed in the market and is the reason for the solution proposed according to the invention, which does not exist in the prior art.

[0045] However, the integration proposed by the invention relates to the fact that all overall system components are manufactured in a common semiconductor technology on and in a common semiconductor substrate (IC chip), this semiconductor technology being primarily determined by that used to implement the light source drivers.

[0046] Therefore, one can define: K gV economic expenditure for a system in which only the computer system, the data bus interface and the drivers for the light sources are implemented on a common semiconductor crystal;

[0047] This is then calculated as follows, whereby K GDBRS , K GLEDDRS , K GRSDB and K GLEDDLED are no longer required as costs for the overall system-internal interfaces: K gV = K TDB * K DBDB + K DB + K RS + n LED * K LEDD + n LED + K GLEDDLED

[0048] What we are looking for is: K gV < K gLEDDDS

[0049] This corresponds to: K TDB * K DBDB + K DB + K RS + n LED * K LEDD + n LED * K GLEDDLED < K TBD * K DBDB + K DB + K GDBRS + n LED * K GLEDDRS + K LEDD + K GLEDDLED + K TRS * K GRSDB + K RS + K GRSLEDD

[0050] This calculation can be simplified to: K RS < K GDBRS + n LED * K GLEDDRS + K TRS / K TDB * K GRSDB + K RS + K GRSLEDD

[0051] Solving for n LEDs yields: K RS − K GRSDB * 1 − K TRS / K TDB − K TRS / K TDB * K GRSLEDD / K GLEDDRS < n LED

[0052] It was thus recognized according to the invention that, from a certain number of drivers for the light sources, it is more advantageous, contrary to the generally prevailing opinion of the experts, to accommodate the entire system of data bus interface, computer system and drivers of the light sources on a semiconductor crystal.

[0053] Therefore, the integration of, for example, a CAN transceiver as an exemplary data bus interface is proposed here, together with a microcontroller as a computer system for processing the CAN protocol and for controlling an actuator together with the actuator driver (e.g., driver of the light source).

[0054] This proposal therefore includes a control device for a lighting device with, for example, a CAN bus data bus interface, a computer system, and a driver circuit as a driver for one or more LED light sources, which can typically include one or more light-emitting diodes.

[0055] The CAN bus transceiver, the computer system, and the driver circuit for the one or more light sources are housed on a common semiconductor crystal or substrate, such as a p-doped silicon substrate.

[0056] Instead of being used to control an LED lighting device, the device manufactured according to the invention can also be used to control lighting devices with other light sources, or to control an optical and / or acoustic and / or tactile signaling device, or to control a measuring device, in particular an optical, electrical, inductive, or capacitive measuring device. Accordingly, the at least one driver circuit is then a driver for a signaling device (lamp, loudspeaker, buzzer, vibration element) or for a measuring device (sensor). Advantage of the invention

[0057] The invention enables the cost-effective production of lighting devices for, e.g., vehicle applications as interior lighting or for ambient light applications in vehicles.

Claims

1. A method for manufacturing a device for driving an LED lighting device, - the device being provided with: - an input configured as a data interface for connection to a communication data bus, - an output with at least one terminal for at least one LED lamp, which comprises an LED or a series circuit of LEDs or a group of differently colored LEDs or a series circuit of groups of respectively differently colored LEDs, - a microcontroller, - one or more LED driver circuits, wherein an LED driver circuit is associated with each terminal of the output for an LED lamp, - wherein the data interface, the microcontroller, and the LED driver circuit or the LED driver circuits comprise electronic and / or electrical circuit elements, and - a semiconductor substrate, - wherein the circuit elements of the data interface, of the microcontroller and of the LED driver circuit or the LED driver circuits are integrated into the semiconductor substrate using a semiconductor technology for manufacturing integrated circuits with a smallest possible structure size conditionally specified by the semiconductor technology, and - wherein the semiconductor technology used is determined by what minimum structure size is permissible for the circuit elements of the data interface and of the LED driver circuit or the LED driver circuits in order to ensure their functionality, characterized in that - the data interface and / or the at least one LED driver circuit comprise circuit elements, the structure size of which is equal to the smallest possible structure size determined by the semiconductor technology, and - the microcontroller comprises circuit elements of which those having the smallest structure size have a structure size which is equal to the structure size of those circuit elements of the data interface and / or of the at least one LED driver circuit having the smallest possible structure size determined by the semiconductor technology.

2. The method according to claim 1, characterized in that the device comprises a voltage regulator comprising circuit elements integrated in the semiconductor substrate, wherein the semiconductor technology used is determined by what minimum structure size is permissible for the circuit elements of the data interface, of the LED driver circuit or the LED driver circuits and of the voltage regulator in order to ensure their functionality.

3. The method according to claim 1 or 2, characterized in that the device comprises a test interface having electronic and / or electrical circuit elements integrated in the semiconductor substrate for testing the functionality of the data interface and / or of the microcontroller and / or of the LED driver circuit or the LED driver circuits and / or of the voltage regulator, if present, wherein the semiconductor technology used is determined by what minimum structure size is permissible for the circuit elements of the data interface, of the LED driver circuit or the LED driver circuits, of the voltage regulator and of the test interface in order to ensure their functionality.

4. The method according to any one of claims 1 to 3, characterized in that the device comprises a sensor system interface having electrical and / or electronic circuit elements integrated in the semiconductor substrate for the connection of at least one sensor such as a light brightness sensor and / or a light color sensor and / or a sun sensor, which are or can be connected to a data communication bus adapted to be connected to the sensor system interface, wherein the semiconductor technology used is determined by what minimum structure size is permissible for the circuit elements of the data interface, of the LED driver circuit or the LED driver circuits, of the voltage regulator, of the test interface and of the sensor system interface (PSI5, PSI3) in order to ensure their functionality.

5. The method according to any one of claims 1 to 4, characterized in that the microcontroller comprises only a functionality required to drive the LED driver circuit or the LED driver circuits in accordance with signals received from the data interface and / or signals received from the sensor system interface, if present, and required to process signals received from the test interface, if present.

6. The method according to any one of claims 1 to 5, characterized in that the circuit elements, the functionality of which must be ensured when manufacturing by means of the semiconductor technology used, are transistors and / or conductor tracks.

7. The method according to any one of claims 1 to 6, characterized in that the semiconductor technology used is a semiconductor technology with a smallest possible structure size that is larger than 85 nm or larger than 90 nm or larger than 100 nm or larger than 110 nm or larger than 120 nm or larger than 130 nm or larger than 140 nm or larger than 150 nm or larger than 160 nm or larger than 170 nm or larger than 180 nm or larger than 190 nm.

8. The method according to any one of claims 1 to 6, characterized in that the semiconductor technology used is a semiconductor technology with a smallest possible structure size that is smaller than 200 nm or smaller than 190 nm or smaller than 180 nm or smaller than 170 nm or smaller than 160 nm or smaller than 150 nm or smaller than 140 nm or smaller than 130 nm or smaller than 120 nm or smaller than 110 nm or smaller than 100 nm or smaller than 90 nm or smaller than 85 nm.