Method for monitoring a soldering process, control unit for carrying out the process, soldering system, soldering workstation, data carrier signal

Abstract

Method (100) for monitoring a soldering process (26, 60) in which several soldering process objects (11) are soldered using at least one soldering tool (52, 60), comprising the following steps: a) (102) Assigning an identification parameter (104) to each soldering process object (11); b) (104) Generating image data (45a, 54a, 70a, 72a) depicting the soldering process (26, 60); c1) (108) Arrange for the identification parameter (104) belonging to the soldering process object (11) and a time range (110) representing the respective soldering process object (11) of the image data (45a, 54a, 70a, 72a) to be assigned to the image data (45a, 54a, 70a, 72a) when soldering, wherein the image data (45a, 54a, 70a, 72a) are searchable according to at least one of the assigned identification parameters (104) and wherein the time range (110) of the image data (45a, 54a, 70a, 72a) is identifiable in which the soldering process object (11) associated with the identification parameter (104) sought is depicted.

Description

[0001] The invention relates to a method for monitoring a soldering process in which several soldering process objects are soldered using at least one soldering tool, a control unit for a soldering system or a soldering robot for carrying out the method, a soldering system or a soldering robot with a control unit according to the invention, a soldering workstation with an evaluation unit for carrying out the method, a data carrier signal and a computer program.

[0002] In soldering processes, components such as printed circuit boards and other parts, especially resistors, integrated circuits (ICs), are soldered together using soldering tools. The solder joints, i.e., the contacts of the components to be soldered, are heated by a soldering tool so that the solder connects the contacts and forms the finished solder joints. The quality of soldering processes depends on many factors. Quality control of the solder joints is usually carried out after completion of the soldering process by visual inspection or X-ray. Continuous quality control of the actual soldering process using conventional methods is not common due to space limitations in soldering systems, soldering robots, or at soldering workstations.

[0003] From US patent 11,525,736 B2, a computer is known that identifies one or more temperature-sensitive components based on the part data in a bill of materials (BOM) for soldering onto a printed circuit board assembly. The BOM is a record containing part data with a reference designation. The computer determines whether temperature-sensitive components are present in the BOM. Based on the finding that at least one temperature-sensitive component is present in the BOM, the computer determines temperature limits for each temperature-sensitive component based on the reference designation, measuring instruments, and using thermographic cameras that measure the temperatures of the temperature-sensitive components during the soldering process in the reflow oven.Based on the determination that the measured temperatures of the temperature-sensitive components exceed the temperature limits, the computer then calculates the time elapsed outside the temperature limit when the measured temperatures of the temperature-sensitive components exceeded the temperature limits. A message is then generated and displayed with a map layout that shows at least one of the one or more temperature-sensitive components in a different color to mark the location where a temperature exceedance was measured.

[0004] EP 3 648 920 B1 discloses a method for operating a soldering device by using a camera to capture an image of at least part of the soldering device. The current operating state of the soldering device can then be determined using the captured image and a reference image.

[0005] The present invention is based on the objective of improving the monitoring of soldering processes.

[0006] The problem is solved by a method for monitoring a soldering process according to claim 1. In the soldering process, several soldering process objects are soldered using at least one soldering tool. The method comprises the following steps: a) Assigning an identification parameter to each soldering process object; b) Generating image data that depicts the soldering process; c1) To ensure that, when soldering a respective soldering process object, the identification parameter belonging to the soldering process object and a time range of the image data representing the respective soldering process object are assigned to the image data.

[0007] The method has the advantage that time periods showing specific soldering process objects can be found quickly and reliably for later quality control and other evaluations of the soldering process.

[0008] It is also conceivable to apply the method to preparatory processes in a soldering system, for example when applying flux to soldering process objects using a flux nozzle or preheating the soldering process objects before the actual soldering.

[0009] A soldering object can be, for example, a component such as a resistor, IC, LED, and others. A printed circuit board (PCB) onto which components are to be soldered can also be a soldering object. The components can be of any type, such as through-hole technology (THT), surface-mount technology (SMD), and others. A soldering process can encompass all the necessary steps required to solder the soldering objects together. A soldering object can also be a sub-object of one of the components or a PCB, in this sense, for example, a contact pad on the PCB and / or a pin of one of the components described above. The steps can already include applying flux or preheating the soldering objects.

[0010] An identification parameter is suitable for identifying the respective soldering process object. The identification parameters can be in the form of a number, a name, a numerical value, or in another data format.

[0011] The term "soldering process" can refer to a manual soldering process using a hand-held soldering iron, as well as automated soldering processes using a soldering system with a nozzle that has a stationary solder wave. An automated soldering process using a hand-held soldering iron guided by a soldering robot is also conceivable. Furthermore, a laser can be used as a soldering tool to melt a solder joint and / or the solder at the joint. An example of a soldering process is the soldering of a printed circuit board (PCB) with several components mounted on it, where both the PCB and the components can be soldering objects, and the components can be processed using different soldering tools. Parameters for identifying the soldering tools used can also be assigned to the image data.

[0012] The generation is preferably carried out using at least one camera or imaging device directed at the soldering tool. It is particularly advantageous if an area of ​​the soldering tool in contact with a solder joint lies within a detection area of ​​the camera or imaging device. This area can, for example, be a stationary wave of solder from a soldering nozzle, the tip of a soldering iron, or a laser beam.

[0013] It is conceivable that the initiation in step c1) is carried out by issuing a command from a control unit controlling the soldering process to start the soldering of the respective soldering process object.

[0014] Alternatively to step c1), step c2) can be performed, in which the soldering process object is detected in the image data and the identification parameter associated with the soldering process object and a time range of the image data representing the respective soldering process object are assigned to the image data. Preferably, the detection takes place during the generation of the image data.

[0015] It is advantageous if the image data includes video data depicting the soldering process, identification parameters, and metadata representing at least the beginning of the time domain. In addition to the aforementioned identification parameters and the time domain, the metadata can also include further data and parameters, such as the soldering tool used to solder the object.

[0016] It is conceivable that the identification parameter is an integer value.

[0017] Advantageously, the image data is made available for display after steps a), b), and c1) or c2). It is further advantageous if the provided image data is output and / or stored as a data carrier signal after the procedure has been carried out. The data carrier signal can be transmitted to a cloud, via a network, and / or to physical storage such as a hard drive.

[0018] The image data generated, output, and / or stored by the method are searchable according to at least one of the identification parameters assigned, in particular in step a). The time range of the image data in which the soldering process object corresponding to the searched identification parameter is depicted is identifiable. This time range is preferably identifiable by the identification parameter. It is conceivable that the identified time range of the image data could be displayed.

[0019] Advantageously, even during the soldering process of a soldering object, the generated image data is compared with the image data of a target soldering process for that object. Deviations in the image data from the target soldering process are detected, and a further step is initiated if a deviation is detected. This further step could, for example, display an error message, sound an audible warning signal, or stop the soldering system or soldering robot. This allows high quality to be achieved even during the soldering process.

[0020] It is conceivable to provide image data with metadata from at least two consecutive soldering processes in which the same soldering process objects are soldered, whereby a comparison and detection of deviations in the image data and / or metadata of the at least two soldering processes takes place. This allows errors or problems in the soldering process or on a soldering system to be detected quickly and easily, and appropriate action to be taken, such as initiating maintenance.

[0021] The problem is also solved by a control unit according to claim 12. The control unit is for a soldering system or a soldering robot and executes the method according to the invention. Preferably, the control unit includes a display for showing the image data, in particular the time range in which the soldering process object associated with a searched identification parameter is shown. Furthermore, the control unit can also include an input, wherein the control unit, together with the input and the display, can then form a computer system that can be spatially separate from a soldering system.

[0022] Preferably, a computer program is executed on the control unit or a computer system, which reads the data carrier signal of the image data from the inventive method.

[0023] Preferably, an identification parameter of a soldering process object can be entered into the computer program, whereby the time range of the image data in which the soldering process object associated with the entered identification parameter is depicted is displayed.

[0024] The problem is also solved by a soldering system or a soldering robot comprising at least one control unit according to the invention, at least one soldering tool and at least one camera per soldering tool.

[0025] The problem is also solved by a soldering workstation comprising at least one soldering tool, a camera, and an evaluation unit, wherein the evaluation unit performs the method according to the invention. The evaluation unit is preferably a computer.

[0026] The problem is also solved by a data carrier signal that transmits the image data generated by the method according to the invention.

[0027] Further details and advantageous embodiments of the invention can be found in the following description, which provides further description and explanation of exemplary embodiments of the invention.

[0028] They show: Fig. 1: a soldering system; Fig. 2: a schematic representation of an automated soldering process; Fig. 3: a schematic representation of a soldering process using a soldering iron; Fig. 4: a schematic procedure for optimizing soldering processes; and Fig. 5; a computer system on which a computer program is executed.

[0029] Based on the Fig. 1, Fig. 2 to Fig. 3. Soldering processes 26, 60 are to be explained, the monitoring of which is carried out using a method 100, which is described in Fig. As shown schematically in section 4, improvements will be made.

[0030] The Fig. Figure 1 shows a soldering system 10 for soldering soldering process objects 11. The soldering system 10 can be either a selective soldering system with individual solder pots or a wave soldering system. The soldering process objects 11 are placed in the Fig. Figure 2 shows an example. The soldering system 10 comprises various modules, the first being a flux module 12, the second a heating module 14, and the third a soldering module 16. The soldering system 10 is enclosed in a housing 18. Depending on the soldering process, the soldering system 10 may also include more or fewer than the three modules 12, 14, and 16 shown. For example, two flux modules 12, several heating modules 14, or several soldering modules 16 are conceivable, but not shown.

[0031] For example, a control unit 20, a control element 22 in the form of a keyboard, and a display 24 in the form of a screen are arranged in the middle module 14. However, it is also conceivable to implement the control unit 20, the control element 22, and the display 24 as a computer system 120 spatially separate from the soldering system 10, as shown in Fig. Figure 5 is shown schematically. Various inputs to the control unit 20 are possible via the operating element 22.

[0032] Modules 12, 14, and 16 are interconnected and are preferably controlled by control unit 20. Control unit 20 can receive data signals and execute both computer programs and processes. It is also conceivable to deploy modules 12, 14, and 16 individually and in separate locations, for example, at different stations in a production line.

[0033] The in Fig. The diagram shown is intended to illustrate the basic sequence of a soldering process 26 for soldering soldering process objects 11 using the soldering system 10. The soldering process 26 has three steps 28, 30, and 32. In all steps 28, 30, and 32, the soldering process objects 11 are shown as a component 34, in this case a through-hole resistor, and a printed circuit board 36 into which the component 34 is inserted. The printed circuit board 36 has a top side 36a and a bottom side 36b. The soldering process objects 11 move through the soldering process 26 from left to right, as shown in the diagram. Fig. 1 soldering system shown 10.

[0034] In the first step 28, which is carried out in the soldering system 10 in the flux module 12, flux 42 is applied using a movable spray head 38. The spray head 38 includes a flux nozzle 40 for applying flux 42 to the solder joints on the underside of the printed circuit board 36b. The solder joints 44 to be soldered consist, in this case, of the two leads of the component 34, which are inserted through the printed circuit board 36, and of the corresponding contact pads on the printed circuit board 36 itself. As indicated by the arrows, the spray head 38 is movable in the X and Y directions, so that different areas of the soldering process objects 11 can be sprayed with flux 42. It is also conceivable to move the spray head in a Z direction perpendicular to the X and Y directions.

[0035] In step 28, a camera 45 is arranged on the spray head 38 to generate image data 45a of the application of the flux 42 to the soldering process objects 11. Preferably, the camera 45 moves with the spray head 38. A recording area 45b of the camera is indicated by dashed lines. It can be seen that the recording area 45b covers the area of ​​the soldering process objects 11 onto which flux 42 is applied. The control unit 20 is shown schematically and is connected to the spray head 38 and the camera 45. The image data 45a are transmitted to the control unit 20 and can be processed in method 100 (see Figure 100). Fig. 4) be used.

[0036] Subsequently, in the second step 30 of the soldering process 26, the soldering objects 11 are heated or preheated in preparation for the subsequent selective wave soldering or wave soldering in step 32. Two heating cassettes 46 are shown schematically for heating, with one heating cassette 46 positioned as an upper heater above the soldering objects 11 and the other heating cassette 46 as a lower heater below the soldering objects 11. The heating cassettes 46 emit thermal radiation 48, which is shown schematically as arrows. In the soldering system shown, step 30 of the heating process can be carried out in the second module 14.

[0037] After preparatory steps 28 and 30, the soldering process objects 11 are soldered in step 32. A movable selective wave soldering nozzle, which solders specific solder joints of the soldering process objects 11, is shown as an example soldering tool 52. The soldering tool 52, in particular a solder pot with a soldering nozzle, is movable in the YX direction previously shown with respect to the spray head 38 and additionally in a Z direction to and from the soldering process objects 11. The solder joints 44 to be soldered are thereby brought into contact on the underside 36b of the circuit board 36 with liquid solder 50 of a standing wave supplied by the soldering tool 52. Step 32 can be described in the Fig. The soldering process shown in section 1 is carried out in the third module, section 16. However, it is also conceivable to use any other soldering technology.

[0038] In step 32, another camera 54 is arranged, in particular on the soldering tool 52. The camera 54 generates image data 54a of the soldering of the soldering process objects 11. Preferably, the camera 45 moves with the soldering tool 52. A recording area 54b of the camera is indicated by dashed lines. It can be seen that the recording area 54b covers an area of ​​the soldering tool 52 and an area of ​​the soldering process objects 11 that are currently being soldered. The camera 54 is connected to the control unit 20. The generated image data 54a are transmitted to the control unit 20 and are processed in method 100 (see Figure 100). Fig. 4) used.

[0039] Based on Fig. Figure 3 describes a manual soldering process 60 at a soldering workstation 61. This involves the same soldering process objects 11 as in the previous figures. In this soldering process, the solder joints 44 are soldered by a soldering iron 62 with a tip 64 instead of a soldering tool 52. Solder 66, in the form of a wire, is also manually applied to the solder joint 44. The hands 68 are meant to illustrate that the soldering iron 62 and the solder 66 are handled manually by a person. However, it is also possible to handle the soldering iron 62 and the solder 66 using a soldering robot 68b and to automate this soldering process 60 as well, with the soldering robot 68b then being controlled by a control unit 20. The tip 64 of the soldering iron 62 is brought into contact with the solder joint 44 and thereby heated. The solder 66 is guided to the soldering point 44 and melts due to the heat of the tip 64.The tip 64 remains at the solder joint 44 for a certain soldering time until it is heated to a temperature and the liquefied solder 66 can spread in the solder joint 44 to be soldered, in order to form a properly formed solder joint 44 of high quality and durability.

[0040] In Fig. In Figure 3, a camera 70 is arranged above the soldering process objects 11, and a further camera 72 can also be arranged on the soldering tool 62. The cameras 70 and 72 generate image data 70a and 72a, respectively, in separate recording areas 70b and 70a. The recording areas 70b and 70b are indicated by dashed lines. One recording area 70b can capture all the soldering process objects 11, while the other recording area 72b is directed at the tip 64 and thus always captures the solder joint 44 currently being processed. It is also possible to use only one camera 70 or 72. The cameras 70 and 72 are connected to an evaluation unit 74, to which the image data 70a and 70b are transmitted. The procedure 100 can be executed on the evaluation unit 74, whereby the image data 70a and 72a can be used.

[0041] In Fig. Figure 4 schematically shows procedure 100. Procedure 100 is executed, for example, on the control unit 20 and / or the evaluation unit 74. Using procedure 100, the previously described soldering processes 26, 60 can be monitored better than before, and quality control of the individual soldered joints 44 can be carried out using the soldering process objects 11.

[0042] In a first step 102, each soldering process object 11 occurring in the soldering process 26, 60 is assigned an identification parameter 104. This can be done, for example, using a database containing design data or soldering process sequences, before the soldering process 26, 60, or by means of object recognition of the soldering process objects 11 using image processing during the soldering process 26, 60. The identification parameters 104 can be assigned in the form of integer values.

[0043] In the second step 106, the image data 45a, 54a, 70a, 72a are processed as described above. Fig. 2 and Fig. The image data described in section 3 is generated by at least one of the cameras 45, 54 or 70, 72. The image data 45a, 54a, 70a, 72a are, in particular, video data depicting one of the soldering processes 26, 60. The image data 45a, 54a, 70a, 72a cover a time range as long as the entire soldering process 26, 60.

[0044] In a third step 108, it is ensured that when a respective soldering process object 11 is soldered, the identification parameter 104 belonging to the soldering process object 11 and a time range 110 representing the respective soldering process object 11 are assigned to the image data 45a, 54a, 70a, 72a. Each soldering process object 11 is represented in the image data 45a, 54a, 70a, 72a within a certain time range in which it is soldered by the corresponding soldering tool 52, 60. In the case of an automated soldering process 26, as takes place in the soldering system 10, the assignment can be carried out by issuing a command from the control unit 20 controlling the soldering process 26 to start the soldering 32 of the respective soldering process object 11. The assignment is made in particular in meta-data 112, which preferably represent the time domain 110 and the identification parameters 104.

[0045] As an alternative to the third step 108, another third step 114 can be performed, in which the soldering process object 11 is recognized in the image data 45a, 54a, 70a, 72a during the generation of the image data, and in which the identification parameter 104 belonging to the soldering process object 11 and a time range 110 representing the respective soldering process object 11 are assigned to the image data 45a, 54a, 70a, 72a. This can be done, for example, in the manual soldering process 60 using the evaluation unit 74. Accordingly, at least one time range 110 with at least one identification parameter 104 is assigned to the image data.

[0046] Regardless of whether step 108 or step 114 is executed, the image data 45a, 54a, 70a, 72a subsequently include not only the video data but also the associated metadata 112. The metadata 112 can also include further parameters such as tool parameters for identifying the soldering tool 52, 60 and / or the solder alloy used. The metadata 112 could also include the condition of the soldering tool 52, 62.

[0047] In a further step 116, the image data 45a, 54a, 70a, 72a, along with the metadata 112, are made available for display, for example on the display 24, or output as a data carrier signal 118, which can be stored in a cloud or other storage medium. The output of the data carrier signal 118 is described in the Fig. 2 and Fig. 3 from the control unit 20 and the evaluation unit 74 indicated.

[0048] The previously mentioned improved monitoring of the soldering process is exemplified in Fig. Figure 5 shows a schematically indicated computer system 120. The computer system 120 comprises a processing unit 122, an input 124, and a display 126. The computer system 120 can, as shown in Figure 5, be used to operate a computer system 120. Fig. As described in section 1, the soldering system 10 is integrated into a soldering machine. The data carrier signal 118, comprising the image data 45a, 54a, 70a, 72a, is read in. A computer program 130 is executed on the computer system 120.

[0049] An identification parameter 104 can be entered. Using the metadata 112, the image data 45a, 54a, 70a, 72a can be searched for at least one identification parameter 104, and a time range 110 of the image data 45a, 54a, 70a, 72a, in which the soldering process object 11 belonging to the searched identification parameter 104 is depicted, can be identified. The computer program 130 then causes the computer system 120 to display the time range 110 on the display 126, in which the soldering process object 11 belonging to the entered identification parameter 104 is depicted. Thus, the video is displayed at the point where the searched soldering process object, for example, component 34, is soldered. This eliminates the time-consuming search through image data 45a, 54a, 70a, 72a for the sought-after soldering process object 11.

[0050] It is conceivable to apply the method 100 not only to the soldering process 26 itself, but also separately to the application of the flux 42 in step 28 of the Fig. 2. Image data 45a could be assigned to a soldering process object 11 during the application of the flux 42 for a respective time range based on an identification parameter 104 and finally displayed with the computer system 120.

Claims

[1] Method (100) for monitoring a soldering process (26, 60) in which several soldering process objects (11) are soldered using at least one soldering tool (52, 60), comprising the following steps: a) (102) Assigning an identification parameter (104) to each soldering process object (11); b) (104) Generating image data (45a, 54a, 70a, 72a) depicting the soldering process (26, 60); c1) (108) Arrange for the identification parameter (104) belonging to the soldering process object (11) and a time range (110) representing the respective soldering process object (11) of the image data (45a, 54a, 70a, 72a) to be assigned to the image data (45a, 54a, 70a, 72a) when soldering, wherein the image data (45a, 54a, 70a, 72a) are searchable according to at least one of the assigned identification parameters (104) and wherein the time range (110) of the image data (45a, 54a, 70a, 72a) is identifiable in which the soldering process object (11) associated with the identification parameter (104) sought is depicted. [2] Method (100) according to claim 1, wherein the initiation in step c1) (108) is carried out by issuing a command from a control unit (20) controlling the soldering process (26) to start the soldering of the respective soldering process object (11). [3] Method (100) according to claim 1, wherein, as an alternative to step c1) (108), a step c2) (114) is performed in which the soldering process object (11) is recognized in the image data (45a, 54a, 70a, 72a) and in which the identification parameter (104) belonging to the soldering process object (11) and the time range (110) mapping into the respective soldering process object (11) of the image data (45a, 54a, 70a, 72a) is assigned to the image data (45a, 54a, 70a, 72a). [4] Method (100) according to any of the preceding claims, wherein the image data (45a, 54a, 70a, 72a) comprise video data depicting the soldering process (26, 60) and the identification parameters (104) and metadata (112) representing at least one start of the time domain (110). [5] Method (100) according to any of the preceding claims, wherein the identification parameter (104) is an integer value. [6] Method (100) according to any of the preceding claims, wherein the image data (45a, 54a, 70a, 72a) are made available for display. [7] Method (100) according to one of the preceding claims, wherein the provided image data (45a, 54a, 70a, 72a) are output as a data carrier signal (118) and / or stored after carrying out the method (100). [8] Method (100) according to one of the preceding claims, wherein the identified time range (110) of the image data (45a, 54a, 70a, 72a) is displayed. [9] Method (100) according to one of the preceding claims, wherein during the soldering of a soldering process object (11) a comparison of the generated image data (45a, 54a, 70a, 72a) with image data of a target soldering process of this soldering process object (11) is carried out and deviations in the image data (45a, 54a, 70a, 72a) from the image data of the target soldering process are detected and a further step is initiated if a deviation is detected. [10] Method (100) according to one of the preceding claims, wherein image data (45a, 54a, 70a, 72a) with meta-data (112) of at least two soldering processes (26, 60) in which identical soldering process objects (11) are soldered are provided, wherein a comparison and detection of deviations of the image data (45a, 54a, 70a, 72a) and / or meta-data (112) of the at least two soldering processes (26, 60) is carried out. [11] Control unit (20) for a soldering system (10) or a soldering robot (68b) which performs the method (100) according to any one of claims 1 to 10. [12] Control unit (20) according to claim 11 with a display for displaying the image data (45a, 54a, 70a, 72a; 112 [13] Soldering system (10) or soldering robot (68b) comprising a control unit (20) according to claim 11 or 12, at least one soldering tool (52, 60) and at least one camera (45, 54, 70, 72) per soldering tool (52, 60). [14] Soldering workstation (61) comprising at least one soldering tool (52, 60), one camera (70, 72) and one evaluation unit (74), wherein the evaluation unit (74) performs the method (100) according to any one of claims 1 to 10. [15] Data carrier signal (118) that transmits the image data (45a, 54a, 70a, 72a; 112) generated by the method (100) according to any one of claims 1 to 10.

Images