Method for printing conductor paths on an object and associated electronic functionalization method

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of systems and methods for printing a conductive track on the surface of an object. It finds particularly advantageous application in the field of electronic functionalization of objects regardless of their geometry. STATE OF THE ART

[0002] There are several methods of printing conductive tracks onto a surface of a three-dimensional (3D) object.

[0003] In particular, patent document WO 2016 / 097932 proposes to implement: a multi-degree-of-freedom robot for gripping and moving an object on which conductive tracks are to be printed and an inkjet print head for ejecting conductive ink onto the surface of the object, the robot is configured to adjust the position of the object during printing, so that the object moves along a predetermined spatial path relative to the head printing, the print head being at each instant substantially perpendicular to a target surface of the object to be printed at said instant.

[0004] A disadvantage of the system according to patent document WO 2016 / 097932 is that it is not, or is at least poorly, suited to implementation on a production line. It would actually require a stoppage of the production line at least to change the object to be functionalized. In addition, to ensure the positioning accuracy of the conductive tracks, it would be necessary to know precisely how the object was grasped by the robot, which presents certain difficulties, relatively incompatible with the desired level of industrialization. Furthermore, the system according to patent document WO 2016 / 097932 is limited to objects of size, shape, and especially weight, compatible with the handling capabilities of the robot. Another example of a printing process is given in patent document EP 3235355 A1.

[0005] An object of the present invention is therefore to propose a method for printing a conductive track on the surface of an object which makes it possible to overcome at least one of the aforementioned drawbacks. Another object of the present invention is to propose a method for electronically functionalizing an object making it possible to reduce the time between design and manufacturing of prototypes, or even pre-series, of the object.

[0006] Other objects, features, and advantages of the present invention will become apparent from the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY OF THE INVENTION

[0007] To achieve this objective, according to a first aspect of the invention, a method is provided for printing at least one conductive track on the surface of an object. The method uses at least one robot arm having several degrees of freedom and at least one conductive ink print head. At least a portion of the object is arranged in a workspace of said at least one robot.

[0008] The printing process includes the following steps: Carry out a 3D scan of at least part of the surface of the object using a scanner mounted on an arm of the robot which ensures its movement relative to the object, Construct, from the 3D scan carried out, a digital model of the scanned part of the surface of the object using CAD software, Digitally draw, on the previously constructed digital model, a conductive track using the CAD software, Generate, based on the drawing of the conductive track, a trajectory for the print head using the CAD software, and Print said at least one conductive track using the print head mounted on an arm of the robot which ensures its movement relative to the object by following the previously generated trajectory.

[0009] Thus, the method according to the first aspect of the invention allows the performance of 3D scanning and conductive ink printing operations: in a flexible and modular manner, and / or in a simple manner in terms of use and programming, and / or with simplified software and user interface, and / or in a shorter time than existing systems, between the design and manufacture of prototypes or pre-series, and / or in a manner compatible with industrial environments, and / or in a manner that can be integrated into existing automatic production lines.

[0010] Optionally, the printing method as introduced above may further have at least any one of the following features which may be taken separately or in combination.

[0011] In one example, the object is a three-dimensional object.

[0012] According to another example, the method further comprises, following the step of carrying out the 3D scan of the object and before the step of constructing said digital model, a step consisting of identifying the position of the object relative to a reference frame (TCP for “Tool Center Point”) of said at least one robot.

[0013] In another example, the drawing of the conductive track is performed directly on the constructed digital model or is generated by projecting a two-dimensional (2D) digital model of the conductive track onto the constructed digital model.

[0014] According to another example, said at least one robot comprises at least one six-axis articulated arm robot.

[0015] In another example, the scanner includes a laser triangulation sensor. The laser triangulation sensor may include at least one of a laser spot sensor and a laser line sensor.

[0016] According to another example, the printing step also includes the implementation of contact dosing systems (pneumatic or volumetric extrusion through needles) or contactless (piezoelectric jet of ink drops).

[0017] In another example, several conductive tracks are printed which together form at least one printed circuit.

[0018] According to another example, the method further comprises a step of treating at least one conductive track using a spray valve mounted on an arm of the robot which ensures its movement relative to the object, where appropriate following the previously generated trajectory.

[0019] According to another example, the method further comprises, prior to the step of performing the 3D scan, an initialization step comprising the generation of a digital model of at least one of the scanner, the print head and a possible associated dosing system, a pick-and-place machine with integrated vision device and a spray valve.

[0020] In another example, at least two of the scanner, the print head and a possible associated dosing system, a pick-and-place machine with integrated vision device and a spray valve are mounted on the same robot arm.

[0021] As an alternative or in addition to the previous example, at least two of the scanner, the print head and a possible associated dosing system, a pick-and-place machine with integrated vision device and a spray valve are mounted on robot arms that are different from each other. According to this example, a conveyor can be provided which is configured to convey the object from a workspace of a first robot to a workspace of another robot. Alternatively or in addition, at least two robots are arranged at different, and possibly successive, stations of the same production line.

[0022] Another aspect of the invention relates to a computer program product comprising instructions, which when carried out by at least one processor, executes at least the steps of the printing method as introduced above.

[0023] Another aspect of the invention relates to a method for electronically functionalizing an object, comprising: the method of printing at least one conductive track on the surface of an object as introduced above, so as to print on the object a plurality of conductive tracks forming a printed circuit and the placement of electronic components in predefined locations of the printed circuit using a "pick-and-place" machine, with integrated vision device, mounted on an arm of the robot.

[0024] Thus, the method according to the first aspect of the invention allows the positioning of electronic components so as to electronically functionalize an object: in a flexible and modular manner, and / or in a simple manner in terms of use and programming, and / or with simplified software and user interface, and / or in a shorter time than existing systems, between the design and manufacture of prototypes or pre-series, and / or in a manner compatible with industrial environments, and / or in a manner that can be integrated into existing automatic production lines.

[0025] Another aspect of the invention relates to a computer program product comprising instructions, which when carried out by at least one processor, executes at least the steps of the electronic functionalization method as introduced above. BRIEF DESCRIPTION OF THE FIGURES

[0026] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which: There Figure 1 represents a flowchart of an embodiment of the method for printing conductive tracks on the surface of an object according to the first aspect of the invention and of an embodiment of the method for electronically functionalizing an object according to another aspect of the invention. Figure 2 represents the arm robot 2 implemented according to an embodiment of the methods according to the invention. The Figure 3 represents an exploded view of the various tools and their support fixed on the robot arm as illustrated in the Figure 2 . There Figure 4 represents a perspective view of an object as functionalized by implementing the methods according to the invention.

[0027] The drawings are given as examples and are not limiting of the invention. They constitute graphic representations intended to facilitate the understanding of the invention and are not necessarily to the scale of practical applications. DETAILED DESCRIPTION OF THE INVENTION

[0028] A pick-and-place machine is a machine for picking and positioning.

[0029] The term "printed circuit" means a set of conductive tracks arranged together on a support, here materialized by the object, and allowing a set of electronic components to be electrically connected together, with the aim of creating an electronic circuit.

[0030] In reference to the Figure 1, an embodiment of the first aspect of the invention provides for the printing 100 of conductive tracks 10 on the surface of an object 1 by using an arm robot 2 having several degrees of freedom and at least one conductive ink print head 3. The robot 2 may more particularly be a six-axis articulated arm robot. Such a robot is advantageously suitable for controlled and common industrial use.

[0031] Unlike the printing method described in document WO 2016 / 097932, here it is the object 1 which is placed in a workspace of the robot 2; the tools necessary for printing are carried by the robot 2 which ensures their movement relative to the object 1.

[0032] Thus, and as illustrated on the figures 1 to 4 , the method 100 comprises the following steps: Carry out 110 a 3D scan of at least part of the surface of the object 1 using a scanner 4 mounted on an arm of the robot 2 which ensures its movement relative to the object 1, Construct 120, from the 3D scan carried out 110, a digital model of the scanned part of the surface of the object 1 using CAD software, Draw 130 digitally, on the previously constructed digital model 120, a conductive track 10 using the CAD software, Generate 140, based on the drawing 130 of the conductive track 10, a trajectory for the print head 3 using the CAD software, and Print 150 said at least one conductive track 10 using the print head 3 mounted on an arm of the robot 2 which ensures its movement relative to the object 1 by following the previously generated trajectory 140.

[0033] It will be noted that, in particular for the purposes of 3D scanning, the object and more particularly the surface of the object to be scanned 110, is preferably opaque or made opaque. It will also be noted that the object can advantageously be a so-called multi-material object.

[0034] Still referring to the Figure 1 , but also in reference to the Figure 4 , an embodiment of a second aspect of the invention provides for continuing the printing method 100 according to its first aspect by a step 160 of placing electronic components 12, in predefined locations of a printed circuit 11 consisting of a plurality of conductive tracks 10, using a “pick-and-place” machine 6, with integrated vision device 60, mounted on the arm of the robot 2, so as to electronically functionalize the object 1.

[0035] Thus, the object 1 remains in the same position during the printing process 100 and, where applicable, the functionalization process 200. These are the tools necessary for the printing 100 and, where applicable, the functionalization 200 which move relative to the object 1 thanks to their attachment to the arm of the robot 2.

[0036] Therefore, object 1 can be of any weight. Indeed, object 1 rests for example on a platform, defining the workspace of robot 2, which can be adapted to receive an object of any weight. Object 1 can also be of any shape. Since the scanner is configured to perform a 3D scan, the object is not actually limited to a 2D shape; the scanned part of object 1 can have a curved surface. In addition, the 3D scan can only concern a part of object 1. As long as the part of object 1 concerned by the 3D scan enters the workspace of the robot, object 1 can be of any dimensions.On the contrary, in the printing system described in document WO 2016 / 097932, the object is necessarily of reduced weight to be able to be moved by the robot (a six-axis arm robot can generally move objects weighing at most 3 kg), of a shape allowing it to be gripped by the robot, and of dimensions limited by those of the robot's workspace.

[0037] Furthermore, with a view to industrialization, the methods 100 and 200 according to the invention have the advantage, unlike the printing system described in document WO 2016 / 097932, of not requiring the production line to be stopped for each change of object to be functionalized. Two or three robots 2 may even, according to the invention, be provided to act simultaneously or successively on the object 1. For example, at least two robots 2 are arranged at different stations, and possibly successive, of the same production line. Furthermore, the use of several robots 2 each carrying one or more of the tools necessary for printing 100 and, where appropriate, for functionalization 200 may be provided in conjunction with that of a conveyor configured to convey the object from a workspace of a first robot to a workspace of a following robot along the production line.

[0038] The present invention also makes it possible to overcome difficulties inherent in the printing system described in document WO 2016 / 097932, in defining how the robot has grasped the object. Indeed, since the object 1 can remain in a fixed position during the methods 100 and 200 according to the invention, it may be sufficient to ensure that the initial positioning of the object 1 is known with sufficient precision to implement the invention. If necessary, a step may be provided consisting of identifying 125 the position of the object 1 relative to a reference frame (TCP for "Tool Center Point") of the robot 2, in particular following the 3D scan 110 and before the step of constructing (120) said digital model, so as to ensure that the steps of the method carried out using the CAD software are carried out with precision.Indeed, the calibration of the robot 2 and the automatic positioning of the robot 2 relative to the object 1 are, by this location step 125, made possible, even if the positioning of the object 1 in the workspace of the robot 2 is not predefined.

[0039] Another advantage of the printing method according to the first aspect of the invention lies in the fact that it is compatible with a production of the drawing 130 of the conductive track 10 either directly on the constructed digital model 120, or by projection of a 2D digital model of the conductive track 10 onto the constructed digital model 120.

[0040] Furthermore, prior to the step 110 of performing the 3D scan, it is easy to perform, potentially once and for all, an initialization step comprising the generation 105 of a digital model of at least one of the print head 3 and a possible associated dosing system 30, the scanner 4, a spray valve 5, and a pick-and-place machine 6 with integrated vision device 60. Thus, the distance of each tool at each instant when it is requested relative to the object 1 can be determined digitally with great precision, and potentially for the entire duration of use of a robot 2 equipped with the same tools. It should be noted that it is possible to ensure this in other ways, for example involving a distance sensor, such as a laser sensor, and / or a vision device, such as a camera.

[0041] A specific embodiment of a robotic cell implemented according to the printing method 100 and where appropriate the functionalization method 200 will now be described by way of non-limiting example.

[0042] The 2-arm robot can more specifically include a 6-axis robotic arm from the TX2-60 range and its CS9 controller offered by Stäubli. The CS9 controller can also be associated with an SP2 manual control box.

[0043] The print head 3 may more particularly comprise a microdosing valve such as that offered under the reference MDV 3200A by the company VERMES and a precision volumetric dosing pump.

[0044] The dosing system 30 associated with the print head 3 may more particularly comprise a precision volumetric dosing pump, such as that marketed under the brand preeflow ®< eco-PEN300.

[0045] The scanner 4 may more particularly include one of the laser sensors offered by the company Micro-Epsilon, and in particular the one marketed under the reference optoNCDT 1420.

[0046] The spray valve 5 may more particularly comprise a stainless steel spray valve such as that marketed under the reference SV1000SS by the company FISNAR ®<. It may be used in addition to the print heads 3 and 8 for the deposition of i) conductive inks on large surfaces or ii) a varnish for the protection of electronic circuits.

[0047] The pick-and-place machine 6 may more particularly include a CV-X400 industrial vision device and associated peripherals, as offered by the company KEYENCE.

[0048] The vision device 60 integrated into the pick-and-place machine 6 may more particularly comprise a camera and LED ring lighting. The gripping and moving function may more particularly be carried out by a capillary for gripping the electronic components connected to a vacuum pump via a solenoid valve controlled by the controller of the arm robot 2.

[0049] A needle metering valve 8 may also be provided which comprises a pressurized cartridge containing the conductive ink to be deposited and a pneumatic needle valve controlled by the controller of the arm robot 2. This valve may more particularly be one of those marketed by the company VIEWEG ®<.

[0050] Note that each of the print head 3 and its dosing system 30, the scanner 4, the spray valve 5 and the dosing valve 8 can be functionally connected and communicated with the controller of the arm robot 2, if necessary via a suitable controller and / or converter.

[0051] In addition, these different elements are connected to each other via different connections such as RT Ethernet slave buses, an EtherCAT master bus, Ethernet TCP / IP ports and RS232 serial ports and other modular connections (digital I / O, analog I / O).

[0052] Let us also note, with reference to the Figure 3 , that the different tools used according to the chosen embodiment, and in particular that illustrated for which all the tools 3, 4, 5, 6 and 8 used are fixed to the same robot 2 can be via a support 7 taking for example the form of a plate.

[0053] It should be noted that this specific configuration, like other possible ones, has the following advantages: a cell cost of less than €150,000, an installation time of 30 to 60 minutes, and ease of learning, i.e. a training time of approximately % per day.

[0054] The whole can be arranged in conjunction with a cell. The cell defines, for example, all or part of the workspace of robot 2. A majority of elements 2, 3, 4, 5, 6, 7 and 8 can be arranged in the cell.

[0055] Such a robotic cell meets the needs of research laboratories or generally small businesses, that is, it is suitable for operation by people without specific robotics skills, and for the manufacture of prototypes with the shortest possible setup time. The cell is also designed, installed and maintained at low cost.

[0056] A dedicated interface is proposed that has been developed to link to a visual programming language and environment that runs within the Rhinoceros 3D application, and is known as Grasshopper ®< , to automate the entire process, the creation and transfer of the robot 2 program to make the cell usable by people without robotics skills.

[0057] It will also be noted that the plate 7 and the various tools 3, 4, 5, 6 and 8 potentially fixed on it have a total weight advantageously less than 3 kg.

[0058] Furthermore, user safety can be ensured by an automatic stop installed on a cell door. Thus, when robot 2 is operating in automatic mode, opening the door causes robot 2 to stop immediately. The fault caused must be corrected by a specific button in order to allow robot 2 to power up again. In addition, any emergency stop by pressing a red alert button also causes robot 2 to stop immediately.

[0059] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the claims.

Claims

1. Method (100) for printing at least one conductive track (10) on the surface of an object (1), the method (100) implementing at least one arm robot (2) having several degrees of freedom and at least one conductive ink printhead (3), at least one part of the object (1) being disposed in a working space of said at least one robot (2), the method (100) comprising the following steps: - Performing (110) a 3D scan of at least one part of the surface of the object (1) using a scanner (4) mounted on an arm of the robot (2) which ensures its movement relative to the object (1), - Building (120), from a performed 3D scan (110), a digital model of the scanned part of the surface of the object (1) using CAD software, - Digitally drawing (130) a conductive track (10) on the digital model previously built (120) using CAD software, - Generating (140), according to the drawing (130) of the conductive track (10), a trajectory for the printhead (3) using the CAD software, and - Printing (150) said at least one conductive track (10) using the printhead (3) mounted on an arm of the robot (2) which ensures its movement relative to the object (1) by following the previously generated trajectory (140).

2. Method (100) according to the preceding claim, further comprising, following the step (110) of performing the 3D scan of the object (1) and before the step (120) of building said digital model, a step consisting of noting (125) the position of the object (1) with respect to a reference marker of said at least one robot (2).

3. Method (100) according to any one of the preceding claims, wherein the drawing (130) of the conductive track (10) is done directly on the built digital model (120) or is generated by projecting a two-dimensional digital model of the conductive track (10) on the built digital model (120).

4. Method (100) according to any one of the preceding claims, wherein said at least one robot (2) comprises at least one six-axis articulated arm robot.

5. Method (100) according to any one of the preceding claims, wherein the scanner (4) comprises a laser triangulation sensor.

6. Method (100) according to the preceding claim, wherein the laser triangulation sensor comprises at least one from among a laser spot sensor and a laser line sensor.

7. Method (100) according to any one of the preceding claims, wherein the printing step (3) also comprises the implementation of dosing systems (30) by contact or contactless.

8. Method (100) according to any one of the preceding claims, wherein several conductive tracks (10) are printed (150), which together form at least one printed circuit (11).

9. Method (100) according to any one of the preceding claims, comprising a step (155) of processing at least one conductive track (10) using a spraying valve (5) mounted on an arm of the robot (2) which ensures its movement relative to the object (1), if necessary by following the previously generated trajectory (140).

10. Method (100) according to any one of the preceding claims, comprising, prior to the step (110) of performing a 3D scan, an initialisation step comprising the generation (105) of a digital model of the at least one from among the printhead (3) and a possible associated dosing system (30), the scanner (4), a spraying valve (5), and a pick-and-place machine (6) with an integrated viewing device (60).

11. Method (100) according to any one of the preceding claims, wherein at least two from among the printhead (3) and a possible associated dosing system (30), the scanner (4), a spraying valve (5), and a pick-and-place machine (6) with an integrated viewing device (60) are mounted on one same arm of the robot (2).

12. Method (100) according to any one of claims 1 to 10, wherein at least two from among the printhead (3) and a possible associated dosing system (30), the scanner (4), a spraying valve (5), and a pick-and-place machine (6) with an integrated viewing device (60) are mounted on arms of robot(s) (2) which are different from one another.

13. Method (200) for electronically functionalising an object (1), comprising the method (100) of printing at least one conductive track (10) on the surface of an object (1) according to any one of the preceding claims, so as to print a plurality of conductive tracks (10) on the object (1) forming a printed circuit (11) and the placement (160) of electronic components (12) in predefined locations of the printed circuit (11) using a pick-and-place machine (6), with an integrating viewing device (60), mounted on an arm of the robot (2).

14. Computer program product comprising instructions, which, when they are performed by at least one processor of a robot arm with a printhead, executes at least the steps of the method (100) for printing at least one conductive track (10) on the surface of an object (1) according to any one of claims 1 to 12.

15. Computer program product comprising instructions, which, when they are performed by at least one processor of a robot arm with a printhead, executes at least the steps of the method (200) for electronically functionalising an object (1) according to claim 13.