Method of providing electrically conductive pattern, and control system

Abstract

A method of providing an electrically conductive pattern (38) on a reference surface (70), the method comprising applying (S12), using at least one printhead (20) including a plurality of individually controlled nozzles (22), an electrically conductive material (26) onto the reference surface (70) to form the electrically conductive pattern (38). The method further comprises applying (S14), using one of the at least one printhead (20), an electrically insulating material (28) onto the reference surface (70) to form an electrically insulating pattern (74); wherein shapes of the electrically conductive pattern (38) and the electrically insulating pattern (74) are complementary to each other. An object (34), a control system (40) and an application system (12) are also provided.

Description

[0001] METHOD OF PROVIDING ELECTRICALLY CONDUCTIVE PATTERN, AND CONTROL SYSTEM

[0002] Technical Field

[0003] The present disclosure generally relates to provision of electrically conductive patterns. In particular, a method of providing an electrically conductive pattern on a reference surface, an object comprising the electrically conductive pattern, a control system for controlling provision of an electrically conductive pattern on a reference surface, and an application system comprising such control system, are provided.

[0004] Background

[0005] Automotive parts and many other objects maybe painted using an atomizer. The atomizer generates a cloud of paint particles such that the paint is evenly distributed over a large area of the object in several layers. Inkjet painting is a new approach to automotive painting. Instead of dispersing a cloud of paint onto the object using an atomizer, an array of nozzles is used to apply paint in a controlled process.

[0006] JP 2005145099 A teaches to draw a conductor pattern with a conductive ink directly on an inner surface of a vehicle body panel. The conductive ink may be applied by an inkjet method.

[0007] Summary

[0008] One object of the invention is to provide an improved method of providing an electrically conductive pattern on a reference surface.

[0009] A further object of the invention is to provide an improved control system for controlling provision of an electrically conductive pattern on a reference surface. These objects are achieved by the method according to appended claim 1 and the control system according to appended claim io.

[0010] The invention is based on the realization that by digitally printing both an electrically conductive pattern and a complementary electrically insulating pattern on a reference surface, a finish of a top coating thereon can be improved while enabling an electric function by the electrically conductive pattern below the top coating.

[0011] According to a first aspect, there is provided a method of providing an electrically conductive pattern on a reference surface, the method comprising applying, using at least one printhead including a plurality of individually controlled nozzles, an electrically conductive material onto the reference surface to form the electrically conductive pattern. The method further comprises applying, using one of the at least one printhead, an electrically insulating material onto the reference surface to form an electrically insulating pattern; wherein shapes of the electrically conductive pattern and the electrically insulating pattern are complementary to each other.

[0012] The provision of the electrically insulating pattern enables a subsequent coating applied directly or indirectly on the electrically conductive and electrically insulating patterns to be more smooth in comparison with a scenario without such electrically insulating pattern, such as perfectly smooth. A surface finish of such coating can thereby be improved.

[0013] Due to the application of the electrically conductive and electrically insulating materials using the at least one printhead including the individually controlled nozzles, the provision of the electrically conductive and electrically insulating patterns can be made accurate and fast. The accuracy of the method enables provision of a wide range of advanced circuitry by the electrically conductive pattern, such as to control electroluminescent or electrochromic paint on top of the reference surface, to send sensor data and to function as an embedded antenna. The electrically insulating pattern protects the electrically conductive pattern and contributes to maintain a shape of the electrically conductive pattern intact.

[0014] The electrically conductive material may be applied to the reference surface before the electrically insulating material is applied onto the reference surface, or vice versa. As a further option, the electrically conductive material and the electrically insulating material may be alternatingly applied onto the reference surface. The electrically insulating material may contact the electrically conductive material. With a material being applied onto a surface may be meant that the material is brought into contact with the surface. The electrically conductive pattern and / or the electrically insulating pattern may for example be applied as droplets or jets.

[0015] The electrically conductive pattern and / or the electrically insulating pattern may span an area on the reference surface of at least 400 mm2, such as at least 900 mm2, such as at least 2500 mm2. Alternatively, or in addition, a length of the electrically conductive pattern may be at least 200 mm, such as at least 300 mm, such as at least 500 mm. The electrically conductive pattern may be continuous such as to enable an electric current to flow therein along a path.

[0016] The entire reference surface may be covered by the electrically conductive pattern and the electrically insulating pattern. In these cases, a sum of an area of the electrically conductive pattern and an area of the electrically insulating pattern correspond to an area of the reference surface.

[0017] The reference surface may for example be flat or curved. The reference surface may be oriented generally upwards when applying the electrically conductive material and the electrically insulating material thereon. A normal to the reference surface may for example be oriented from horizontal to vertical.

[0018] In some variants, the method employs a first printhead including a plurality of individually controlled nozzles to apply the electrically conductive material, and a second printhead including a plurality of individually controlled nozzles to apply the electrically insulating material. In alternative variants, the method employs a common printhead including a plurality of individually controlled nozzles to apply both the electrically conductive material and the electrically insulating material.

[0019] The at least one printhead including a plurality of individually controlled nozzles maybe an inkjet printhead comprising an array of nozzles. Each nozzle may be configured to eject single droplets of electrically conductive material and / or electrically insulating material. The amount of material in each droplet maybe substantially equal, or equal.

[0020] The nozzles may be binary. That is, at each application instance, each nozzle either applies material of a given volume or does not apply material. An inkjet printhead comprising binary nozzles may be referred to as a digital inkjet printhead. Alternatively, each nozzle may be controlled to eject a variable amount of material. However, binary nozzles simplify application of the material in a pixel pattern.

[0021] Each of the electrically conductive material and the electrically insulating material may be applied in liquid form. In these cases, once the electrically conductive material is sufficiently dry, the electrically insulating material may be applied next to the electrically conductive material, or vice versa. In some variants, the electrically conductive and electrically insulating materials do not mix, e.g., due to size, viscosity and / or physiochemical incompatibilities. In these cases, the electrically insulating material may be applied next to the electrically conductive material while the electrically conductive material is wet, or vice versa.

[0022] The method may further comprise providing at least one industrial robot and controlling the at least one industrial robot to perform relative movements between the at least one printhead and the reference surface while applying the electrically conductive material and the electrically insulating material. For example, the at least one industrial robot may carry the at least one printhead. Alternatively, or in addition, an object comprising the reference surface may be carried by one of the at least one industrial robot.

[0023] The method according to the first aspect may be implemented using a control system as described herein.

[0024] The electrically conductive pattern and the electrically insulating pattern may have a same thickness. A thickness direction may be parallel with a normal of the reference surface. The thickness may for example be at least io micrometers and / or less than 200 micrometers.

[0025] The method may further comprise applying a coating on top of the electrically conductive pattern and the electrically insulating pattern. The electrically conductive pattern can thus be hidden below the coating and may not be visible. The application of the coating may or may not be made using one of the at least one printhead including a plurality of individually controlled nozzles. As an alternative, the coating may be applied using an atomizer. A coating on top of the electrically conductive and electrically insulating patterns may or may not contact the electrically conductive and electrically insulating patterns.

[0026] The coating may include paint, such as a basecoat.

[0027] The electrically conductive pattern may be a first electrically conductive pattern. In these cases, the method may further comprise applying, using at least one printhead, an electrically conductive material onto the first electrically conductive pattern to form a second electrically conductive pattern.

[0028] The first and second electrically conductive patterns may be of different shapes. In some examples, a second area of the second electrically conductive pattern is smaller than a first area of the first electrically conductive pattern. The first and second areas may be parallel with the reference surface. The second electrically conductive pattern may be continuous or discontinuous. In the latter case, the second electrically conductive pattern may form a plurality of connection points, e.g., to electroluminescent paint.

[0029] The coating may be applied onto the second electrically conductive pattern. The coating may include electroluminescent paint.

[0030] The method may further comprise applying an electrically insulating material on a base surface to provide an electrically insulating base layer including the reference surface. The application of this electrically insulating material may or may not be made using one of the at least one printhead including a plurality of individually controlled nozzles. As an alternative, this electrically insulating material may be applied using an atomizer.

[0031] The electrically insulating material may include paint. Thus, the electrically insulating pattern and optionally the electrically insulating base layer may include paint. In these cases, the provision of the electrically conductive pattern becomes integrated into a painting process.

[0032] According to a second aspect, there is provided an object comprising the reference surface, and the electrically conductive material and the electrically insulating material applied onto the reference surface according to the method according to the first aspect. The object may for example be an automotive part, such as a bodywork, a hood, a door and a tailgate. Alternative types of objects may for example include road signs.

[0033] According to a third aspect, there is provided a control system for controlling provision of an electrically conductive pattern on a reference surface, the control system comprising at least one data processing device and at least one memory having at least one computer program stored therein. The at least one computer program comprises program code which, when executed by the at least one data processing device, causes the at least one data processing device to command at least one printhead including a plurality of individually controlled nozzles to apply an electrically conductive material onto the reference surface to form the electrically conductive pattern. The at least one computer program further comprises program code which, when executed by the at least one data processing device, causes the at least one data processing device to command one of the at least one printhead to apply an electrically insulating material onto the reference surface to form an electrically insulating pattern; wherein shapes of the electrically conductive pattern and the electrically insulating pattern are complementary to each other.

[0034] The at least one computer program may comprise program code which, when executed by the at least one data processing device, causes the at least one data processing device to perform, or command performance of, any operation as described herein, in particular as described in connection with the first aspect.

[0035] The at least one computer program may comprise program code which, when executed by the at least one data processing device, causes the at least one data processing device to command a printhead to apply a coating on top of the electrically conductive pattern and the electrically insulating pattern.

[0036] The electrically conductive pattern may be a first electrically conductive pattern. In these cases, the at least one computer program may comprise program code which, when executed by the at least one data processing device, causes the at least one data processing device to command at least one printhead to apply an electrically conductive material onto the first electrically conductive pattern to form a second electrically conductive pattern.

[0037] The coating may be applied onto the second electrically conductive pattern.

[0038] The at least one computer program may comprise program code which, when executed by the at least one data processing device, causes the at least one data processing device to command a printhead to apply an electrically insulating material on a base surface to provide an electrically insulating base layer including the reference surface. According to a fourth aspect, there is provided an application system comprising the control system according to the third aspect, at least one printhead and at least one industrial robot arranged to perform relative movements between the at least one printhead and the reference surface.

[0039] The industrial robot may be programmable in at least one axis, such as in six or seven axes. The application system may further comprise, for each printhead, one or more supply units for supplying application material to the printhead.

[0040] Brief Description of the Drawings

[0041] Further details, advantages and aspects of the present disclosure will become apparent from the following description taken in conjunction with the drawings, wherein:

[0042] Fig. 1: schematically represents a top view of a plant including a vehicle body and an application system comprising three industrial robots;

[0043] Fig. 2: is a block diagram schematically representing components of the application system;

[0044] Fig. 3: schematically represents a cross-sectional side view of one specific example of a nozzle head;

[0045] Fig. 4: schematically represents a partial perspective side view of an object;

[0046] Fig. 5: schematically represents a partial perspective side view of the object and an electrically insulating base layer;

[0047] Fig. 6: schematically represents a partial perspective side view of the object in Fig. 5 and an electrically conductive pattern;

[0048] Fig. 7: schematically represents a partial perspective side view of the object in Fig. 6 and an electrically insulating pattern;

[0049] Fig. 8: schematically represents a partial perspective side view of the object in Fig. 7 and an electrically insulating top layer;

[0050] Fig. 9: schematically represents a partial perspective side view of the object in Fig. 8 and a coating;

[0051] Fig. io: schematically represents a partial perspective side view of the object and a first electrically conductive pattern;

[0052] Fig. n: schematically represents a partial perspective side view of the object in Fig. io and a first electrically insulating pattern;

[0053] Fig. 12: schematically represents a partial perspective side view of the object in Fig. n and a second electrically conductive pattern;

[0054] Fig. 13: schematically represents a partial perspective side view of the object in Fig. 12 and a second electrically insulating pattern;

[0055] Fig. 14: schematically represents a partial perspective side view of the object in Fig. 13 and a coating; and

[0056] Fig. 15: is a flowchart outlining general steps of a method.

[0057] Detailed Description

[0058] In the following, a method of providing an electrically conductive pattern on a reference surface, an object comprising the electrically conductive pattern, a control system for controlling provision of an electrically conductive pattern on a reference surface, and an application system comprising such control system, will be described. The same or similar reference numerals will be used to denote the same or similar structural features.

[0059] Fig. 1 schematically represents a top view of a plant 10, here exemplified as a plant for painting vehicle bodies. The plant 10 includes an application system 12. The application system 12 of this specific and non-limiting example comprises a first industrial robot 14a, a second industrial robot 14b and a third industrial robot 14c. One, several or all of the first to third industrial robots 143-140 may also be referred to with reference numeral "14".

[0060] The first industrial robot 14a of this specific and non-limiting example comprises a platform 16 and a manipulator 18 movable relative to the platform 16. The manipulator 18 may for example be a serial manipulator programmable in three or more axes, such as in six or seven axes. The manipulator 18 carries a first inkjet printhead 20a. The first inkjet printhead 20a of this example comprises a two-dimensional array of a plurality of individually controlled nozzles 22. The array may alternatively be onedimensional or three-dimensional.

[0061] The first industrial robot 14a of this example further comprises a first supply unit 24a. The first supply unit 24a is here arranged to supply an electrically conductive material 26 to the first inkjet printhead 20a for ejection by the nozzles 22. The first inkjet printhead 20a can print the electrically conductive material 26 with sub-millimeter accuracy. One example of the first inkjet printhead 20a is described in WO 2023041161 Al, the content of which is incorporated herein in its entirety by reference.

[0062] The electrically conductive material 26 may or may not be paint, the electrically conductive material 26 may for example be a liquid containing pulverized metal, such as copper or aluminum. In case a bonding agent is used in the electrically conductive material 26, also such bonding agent may be electrically conductive. In some variants, the electrically conductive material 26 is electroluminescent paint.

[0063] The second industrial robot 14b is here of the same design as the first industrial robot 14a. The second industrial robot 14b comprises a second inkjet printhead 20b and a second supply unit 24b. The second inkjet printhead 20b is of the same design as the first inkjet printhead 20a. The second supply unit 24b is here arranged to supply an electrically insulating material 28 to the second inkjet printhead 20b for ejection by the nozzles 22. In this example, the electrically insulating material 28 is an electrically insulating paint in liquid form.

[0064] The third industrial robot 14c of this example is here of a similar design as the first and second industrial robots 14a, 14b. Instead of an inkjet printhead, the third industrial robot 14c comprises a printhead in the form of an atomizer 20c. The third industrial robot 14c further comprises a third supply unit 24c arranged to supply different coating mediums 30 to the atomizer 20c for atomization by the atomizer 20c. The third supply unit 24c may contain a plurality of sources containing different coating mediums 30, including for example an electrically insulating paint, an electroluminescent paint paint, a primer and a clearcoat. One, several or all of the first inkjet printhead 20a, second inkjet printhead 20b and atomizer 20c may also be referred to with reference numeral "20".

[0065] The plant 10 of this example further includes a vehicle body 32 for a passenger car. The vehicle body 32 of this specific and non-limiting example comprises a bodywork 34a, a hood 34b, two doors 34c and a tailgate 34d.

[0066] Due to the first inkjet printhead 20a, the second inkjet printhead 20b and the atomizer 20c being carried by the first industrial robot 14a, the second industrial robot 14b and the third industrial robot 14c, respectively, the electrically conductive material 26, the electrically insulating material 28 and the coating mediums 30 can be provided over the entire bodywork 34a.

[0067] In the specific and non-limiting example in Fig. 1, a first paint area 36a of electroluminescent paint is provided on the bodywork 34a, and a second paint area 36b of electroluminescent paint is provided on the hood 34b. The electroluminescent paint in first and second paint areas 36a, 36b may for example be applied using the first inkjet printhead 20a. Fig. 1 further shows a first electric connection 38a on the bodywork 34a to the first paint area 36a and a second electric connection 38b on the hood 34b to the second paint area 36b. The first and second electric connections 38a, 38b are examples of electrically conductive patterns and are here hidden below an external paint layer. The first and second paint areas 36a, 36b are here respectively exemplified as a triangle and a star. When electric current is applied to the first and second electric connections 38a, 38b, the first and second paint areas 36a, 36b can be controlled to glow accurately and independently.

[0068] Moreover, in the specific and non-limiting example in Fig. 1, an electric circuit 38c is provided on the hood 34b. The electric circuit 38c is hidden below an external paint layer and functions as an antenna. The electric circuit 38c is a further example of an electrically conductive pattern. The first and second electric connections 38a, 38b and the electric circuit 38c may be electrically connected to one or more electric sources (not shown), e.g., inside of an engine compartment. To this end, the first electric connection 38a may be provided to an edge of the bodywork 34a and the second electric connection 38b and the electric circuit 38c may be provided to an edge of the hood 34b, e.g., for connection to the one or more electric sources using soldering, clamping or one or more electrically conductive bolts.

[0069] Fig. 2 is a block diagram schematically representing components of the application system 12. The application system 12 comprises a control system 40. The control system 40 of this specific and non-limiting example comprises a first controller 42a, a second controller 42b and a third controller 42c associated with the first industrial robot 14a, the second industrial robot 14b and the third industrial robot 14c, respectively.

[0070] The first controller 42a comprises a first data processing device 44a and a first memory 46a having a first computer program stored therein. The first computer program comprises program code which, when executed by the first data processing device 44a causes the first data processing device 44a to perform, or command performance of, various operations associated with the first industrial robot 14a, for example including controlling the first supply unit 24a, the manipulator 18 of the first industrial robot 14a and the nozzles 22 of the first inkjet printhead 20a.

[0071] The second controller 42b comprises a second data processing device 44b and a second memory 46b having a second computer program stored therein. The second computer program comprises program code which, when executed by the second data processing device 44b causes the second data processing device 44b to perform, or command performance of, various operations associated with the second industrial robot 14b, for example including controlling the second supply unit 24b, the manipulator 18 of the second industrial robot 14b and the nozzles 22 of the second inkjet printhead 20b. The third controller 42c comprises a third data processing device 44c and a third memory 46c having a third computer program stored therein. The third computer program comprises program code which, when executed by the third data processing device 44c causes the third data processing device 44c to perform, or command performance of, various operations associated with the third industrial robot 14c, for example including controlling the third supply unit 24c, the manipulator 18 of the third industrial robot 14c and atomizer 20c.

[0072] Fig. 3 schematically represents a cross-sectional side view of one specific example of a nozzle head 48 of the first inkjet printhead 20a. The first inkjet printhead 20a of this example comprises a nozzle head 48 as shown in Fig. 3 for each nozzle 22. The nozzle head 48 comprises a pressurizing chamber 50. The pressurizing chamber 50 can be provided with the electrically conductive material 26 from the first supply unit 24a via a supply path 52. Fig. 3 further shows that the nozzle 22 is provided at a discharge side 54 of the first inkjet printhead 20a.

[0073] The nozzle head 48 comprises a piezoelectric substrate 56. The piezoelectric substrate 56 of this example comprises a first piezoelectric ceramic layer 58a and a second piezoelectric ceramic layer 58b, a common electrode 60 and an individual electrode 62. The common electrode 60 is here positioned between the first and second piezoelectric ceramic layers 58a, 58b. The second piezoelectric ceramic layer 58b is here positioned between the individual electrode 62 and the common electrode 60. The first and second piezoelectric ceramic layers 58a, 58b can be expanded and contracted by applying a voltage from the outside of the nozzle head 48. The application of voltages is controlled by the first controller 42a. The common electrode 60 is electrically connected to corresponding common electrodes 60 of the other nozzle heads 48 of the first inkjet printhead 20a.

[0074] The first and second piezoelectric ceramic layers 58a, 58b are polarized in a thickness direction. When a voltage is applied to the individual electrode 62, the first and second piezoelectric ceramic layers 58a, 58b are distorted due to the piezoelectric effect. Therefore, when a drive signal is applied to the individual electrode 62, the first and second piezoelectric ceramic layers 58a, 58b become convex such that the supply path 52 opens, whereby the electrically conductive material 26 is discharged. In this way, the nozzles 22 can work in a binary fashion to apply single droplets of the electrically conductive material 26 of uniform volume. In a corresponding manner, the nozzles 22 of the second inkjet printhead 20b can work in a binary fashion to apply single droplets of the electrically insulating material 28 of uniform volume.

[0075] Fig. 4 schematically represents a partial perspective side view of an object 34. The object 34 may for example be any of the bodywork 34a, the hood 34b, the doors 34c and the tailgate 34d. The object 34 comprises a base surface 64 which is here an external surface of the object 34, e.g., that is, or that will be, directed externally with respect to the vehicle body 32. The object 34 may be made of metal and optionally include an e-coat thereon, e.g., provided by dipping.

[0076] Fig. 5 schematically represents a partial perspective side view of the object 34 and an electrically insulating base layer 66 having a first thickness 68a, such as 20 micrometers, in a direction transverse to the base surface 64. The electrically insulating base layer 66 has been provided over the entire base surface 64, for example by applying the electrically insulating material 28 onto the base surface 64 using the second inkjet printhead 20b or by applying the coating medium 30 in the form of electrically insulating paint onto the base surface 64 using the atomizer 20c. As shown in Fig. 5, the electrically insulating base layer 66 forms one example of a reference surface 70.

[0077] Fig. 6 schematically represents a partial perspective side view of the object 34 in Fig. 5 and an electrically conductive pattern 38d. The electrically conductive pattern 38d may for example constitute, or correspond to, the electric circuit 38c. The electrically conductive pattern 38d has a second thickness 68b, such as at least 40 micrometers. Once the electrically insulating base layer 66 has dried, the electrically conductive pattern 38d is provided by applying the electrically conductive material 26 onto the reference surface 70 using the first inkjet printhead 20a guided by the first industrial robot 14a under control of the first controller 42a. An electric circuit is thereby printed on the reference surface 70. The electrically conductive pattern 38d is provided on the object 34 without requiring adhesive or manual work. The electrically conductive pattern 38d reaches a side of the reference surface 70. Thus, no holes have to be drilled in the object 34 in order to electrically connect the electrically conductive pattern 38d to an electric source.

[0078] In this specific example, the electrically conductive pattern 38d has been provided by first printing a first electrically conductive sub-layer 72a, and then printing a second electrically conductive sub-layer 72b thereon. In case a width of the first inkjet printhead 20a is larger than a width of the electrically conductive pattern 38d, each of the first and second electrically conductive sub-layers 72a, 72b may be applied with a single stroke of the first inkjet printhead 20a.

[0079] Fig. 7 schematically represents a partial perspective side view of the object 34 in Fig. 6 and an electrically insulating pattern 74a. Once the electrically conductive pattern 38d has dried, the electrically insulating pattern 74a is provided by applying the electrically insulating material 28 onto the reference surface 70 using the second inkjet printhead 20b guided by the second industrial robot 14b under control of the second controller 42b. In this example, the entire reference surface 70 is covered by the electrically conductive pattern 38d and the electrically insulating pattern 74a.

[0080] In this specific example, the electrically insulating pattern 74a has been provided by first printing a first electrically insulating sub-layer 76a, then printing a second electrically insulating sub-layer 76b on the first electrically insulating sub-layer 76a, and then printing a third electrically insulating sublayer 76c on the second electrically insulating sub-layer 76b. Also the electrically insulating pattern 74a has the second thickness 68b, i.e., the same thickness as the electrically conductive pattern 38d. An area of the electrically insulating pattern 74a shown in Fig. 7 may for example be at least 400 mm2.

[0081] As shown in Fig. 7, a shape of the electrically insulating pattern 74a is complementary to a shape of the electrically conductive pattern 38d. The electrically insulating pattern 74a contacts the sides of the electrically conductive pattern 38d. The digital printing of both the electrically conductive and electrically insulating patterns 38d, 74a provides an exact control of the locations of the electrically conductive and electrically insulating patterns 38d, 74a. Moreover, a risk of any valley being created therebetween is reduced.

[0082] As can be gathered from Fig. 7, the shape of the electrically conductive pattern 38d is stably maintained by the electrically insulating pattern 74a, which improves the structural integrity of the electrically conductive pattern 38d. For example, due to the electrically insulating pattern 74a, the electrically conductive pattern 38d can strongly resist lateral forces acting thereon.

[0083] Fig. 8 schematically represents a partial perspective side view of the object 34 in Fig. 7 and an electrically insulating top layer 78 having a third thickness 68c, such as 20 micrometers. Once the electrically insulating pattern 74a has dried, the electrically insulating top layer 78 is provided by applying the electrically insulating material 28 onto the electrically conductive pattern 38d and the electrically insulating pattern 74a using the second inkjet printhead 20b. The electrically conductive pattern 38d is thereby sealed off by the electrically insulating top layer 78. Alternatively, the electrically insulating top layer 78 can be provided by applying the coating medium 30 in the form of electrically insulating paint using the atomizer 20c.

[0084] Fig. 9 schematically represents a partial perspective side view of the object 34 in Fig. 8 and a coating 80a having a fourth thickness 68d, such as 20 micrometers. Once the electrically insulating top layer 78 has dried, the coating 80a is applied thereon, e.g., using the atomizer 20c guided by the third industrial robot 14c under control of the third controller 42c. The coating 80a may for example contain a primary layer, a basecoat layer of paint and a clearcoat layer. As shown in Fig. 9, the coating 80a has a smooth top surface. This is for example beneficial to reduce drag on a vehicle comprising the vehicle body 32.

[0085] Instead of the coating 80a applied onto the electrically insulating top layer 78, a further electrically conductive pattern may be provided thereon, followed by a further electrically insulating top layer and the coating 80a. In this way, a plurality of layers of circuitry can be formed below the coating 80a.

[0086] Fig. 10 schematically represents a partial perspective side view of the object 34 and a first electrically conductive pattern 38e. Mainly differences with respect to Fig. 6 will be described. The first electrically conductive pattern 38e is provided by applying the electrically conductive material 26 onto the reference surface 70 using the first inkjet printhead 20a. The first electrically conductive pattern 38c has a fifth thickness 68e, such as at least 20 micrometers. As shown, the first electrically conductive pattern 38c of this example is discontinuous and provides two separate electrically conductive paths. One, several or all of the first electric connection 38a, the second electric connection 38b, the electric circuit 38c, the electrically conductive pattern 38d and the first electrically conductive pattern 38c may also be referred to with reference numeral "38".

[0087] Fig. 11 schematically represents a partial perspective side view of the object 34 in Fig. 10 and a first electrically insulating pattern 74b also having the fifth thickness 68e. Mainly differences with respect to Fig. 7 will be described. Once the first electrically conductive pattern 38c has dried, the first electrically insulating pattern 74b is provided by applying the electrically insulating material 28 onto the reference surface 70 using the second inkjet printhead 20b. Also in the example in Fig. 11, a shape of the first electrically insulating pattern 74b is complementary to a shape of the first electrically conductive pattern 38c. Fig. 12 schematically represents a partial perspective side view of the object 34 in Fig. 11 and a second electrically conductive pattern 82 having a sixth thickness 68f, such as at least 20 micrometers. The first and second electrically conductive patterns 38e, 82 may for example constitute, or correspond to, any of the the first and second electric connections 38a, 38b. Once the first electrically insulating pattern 74b has dried, the second electrically conductive pattern 82 is provided by applying the electrically conductive material 26 onto the first electrically conductive pattern 38e using the first inkjet printhead 20a. The second electrically conductive pattern 82 of this example forms two connection points. As shown in Fig. 12, a second area of the second electrically conductive pattern 82 parallel with the reference surface 70 is here substantially smaller than a first area of the first electrically conductive pattern 38c parallel with the reference surface 70.

[0088] Fig. 13 schematically represents a partial perspective side view of the object 34 in Fig. 12 and a second electrically insulating pattern 74c also having the sixth thickness 68f. Once the second electrically conductive pattern 82 has dried, the second electrically insulating pattern 74c is provided by applying the electrically insulating material 28 onto the first electrically insulating pattern 74b and onto the first electrically conductive pattern 38c around the second electrically conductive pattern 82 using the second inkjet printhead 20b. One, several or all of the electrically insulating pattern 74a, the first electrically insulating pattern 74b and the second electrically insulating pattern 74c may also be referred to with reference numeral "74".

[0089] Fig. 14 schematically represents a partial perspective side view of the object 34 in Fig. 13 and a coating 80b having a seventh thickness 68g, such as 20 micrometers. The coating 80b may for example be provided on the second electrically insulating pattern 74c and the second electrically conductive pattern 82 by applying the electrically insulating material 28 thereon using the second inkjet printhead 20b, or by applying the coating medium 30 in the form of electroluminescent paint thereon using the atomizer 20c. One, several or all of the first to seventh thicknesses 68a-68g may also be referred to with reference numeral "68". Each thickness 68 may for example be between io micrometers and 200 micrometers.

[0090] Fig. 15 is a flowchart outlining general steps of a method. The method comprises applying S10 an electrically insulating material 28 on a base surface 64 to provide an electrically insulating base layer 66 including a reference surface 70.

[0091] The method further comprises applying S12, using at least one printhead 20 including a plurality of individually controlled nozzles 22, an electrically conductive material 26 onto the reference surface 70 to form the electrically conductive pattern 38. The method further comprises applying S14, using one of the at least one printhead 20, an electrically insulating material 28 onto the reference surface 70 to form an electrically insulating pattern 74, wherein shapes of the electrically conductive pattern 38 and the electrically insulating pattern 74 are complementary to each other.

[0092] The method may further comprise applying S16, using at least one printhead 20, an electrically conductive material 26 onto the first electrically conductive pattern 38 to form a second electrically conductive pattern 82. The method may further comprise applying S18 a coating 80a; 80b on top of the first electrically conductive pattern 38 and the electrically insulating pattern 74.

[0093] While the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the present invention is not limited to what has been described above. For example, it will be appreciated that the dimensions of the parts may be varied as needed. Accordingly, it is intended that the present invention may be limited only by the scope of the claims appended hereto.

Claims

CLAIMS1. A method of providing an electrically conductive pattern (38) on a reference surface (70), the method comprising:- applying (S12), using at least one printhead (20) including a plurality of individually controlled nozzles (22), an electrically conductive material (26) onto the reference surface (70) to form the electrically conductive pattern (38); characterized in that the method further comprises:- applying (S14), using one of the at least one printhead (20), an electrically insulating material (28) onto the reference surface (70) to form an electrically insulating pattern (74); wherein shapes of the electrically conductive pattern (38) and the electrically insulating pattern (74) are complementary to each other.

2. The method according to claim 1, wherein the electrically conductive pattern (38) and the electrically insulating pattern (74) have a same thickness (68).

3. The method according to any of the preceding claims, further comprising:- applying (S18) a coating (80a; 80b) on top of the electrically conductive pattern (38) and the electrically insulating pattern (74).

4. The method according to claim 3, wherein the coating (80a; 80b) includes paint.

5. The method according to any of the preceding claims, wherein the electrically conductive pattern (38) is a first electrically conductive pattern (38), and wherein the method further comprises:- applying (S16), using at least one printhead (20), an electrically conductive material (26) onto the first electrically conductive pattern (38) to form a second electrically conductive pattern (82).

6. The method according to claim 5 and any of claims 3 and 4, wherein the coating (80a; 80b) is applied onto the second electrically conductive pattern (82).

7. The method according to any of the preceding claims, further comprising:- applying (S10) an electrically insulating material (28) on a base surface (64) to provide an electrically insulating base layer (66) including the reference surface (70).

8. The method according to any of the preceding claims, wherein the electrically insulating material (28) includes paint.

9. An object (34) comprising the reference surface (70), and the electrically conductive material (26) and the electrically insulating material (28) applied onto the reference surface (70) according to the method according to any of the preceding claims.

10. A control system (40) for controlling provision of an electrically conductive pattern (38) on a reference surface (70), the control system (40) comprising at least one data processing device (443-440) and at least one memory (463-460) having at least one computer program stored therein, the at least one computer program comprising program code which, when executed by the at least one data processing device (443-440), causes the at least one data processing device (443-440) to:- command at least one printhead (20) including a plurality of individually controlled nozzles (22) to apply an electrically conductive material (26) onto the reference surface (70) to form the electrically conductive pattern (38); characterized in that the at least one computer program comprises program code which, when executed by the at least one data processing device (443-440), causes the at least one data processing device (44a- 44c) to:- command one of the at least one printhead (20) to apply an electricallyinsulating material (28) onto the reference surface (70) to form an electrically insulating pattern (74); wherein shapes of the electrically conductive pattern (38) and the electrically insulating pattern (74) are complementary to each other.

11. The control system (40) according to claim 10, wherein the at least one computer program comprises program code which, when executed by the at least one data processing device (443-440), causes the at least one data processing device (443-440) to:- command a printhead (20) to apply a coating (80a; 80b) on top of the electrically conductive pattern (38) and the electrically insulating pattern (74).

12. The control system (40) according to claim 10 or 11, wherein the electrically conductive pattern (38) is a first electrically conductive pattern (38), and wherein the at least one computer program comprises program code which, when executed by the at least one data processing device (443-440), causes the at least one data processing device (44a- 44c) to:- command at least one printhead (20) to apply an electrically conductive material (26) onto the first electrically conductive pattern (38) to form a second electrically conductive pattern (82).

13. The control system (40) according to claims 11 and 12, wherein the coating (80a; 80b) is applied onto the second electrically conductive pattern (82).

14. The control system (40) according to any of claims 10 to 13, wherein the at least one computer program comprises program code which, when executed by the at least one data processing device (443-440), causes the at least one data processing device (443-440) to:- command a printhead (20) to apply an electrically insulating material (28) on a base surface (64) to provide an electrically insulating base layer (66) including the reference surface (70).15- An application system (12) comprising the control system (40) according to any of claims 10 to 14, the at least one printhead (20) and at least one industrial robot (14) arranged to perform relative movements between the at least one printhead (20) and the reference surface (70).

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