Method for optimising soldering processes and for creating a soldering program, data carrier signal, soldering program, computer program, computer system, and soldering system

Abstract

The invention relates to a method (100) for optimising soldering processes (26, 60) in which soldering points are soldered by means of a soldering tool, wherein the soldering points (44, 44a) are provided on items to be soldered (11, 11a) and wherein the items to be soldered (11, 11a) have at least one printed circuit board (36, 36a) and at least one component (34, 34a) arranged thereon. First actual soldering point temperatures (IT) for the individual soldering points (44, 44a) to be soldered are simulated (112) taking into account the parameters of the items to be soldered, the parameters of the soldering tool, the target soldering point temperature (ST) and the soldering speed (54) and / or the soldering duration.

Description

[0001] Title: Methods for optimizing soldering processes and for

[0002] Creating a soldering program, data carrier signal, soldering program, computer program and computer system, as well as soldering equipment

[0003] Description

[0004] The invention relates to a method for optimizing soldering processes and / or for creating a soldering program with instructions for carrying out soldering processes, wherein solder joints are soldered using a soldering tool, and the solder joints are provided on the workpiece. The invention also relates to a computer program that causes a computer to carry out the method according to the invention and to a data carrier signal for transmitting instructions that were generated and / or output by means of the method. Furthermore, the invention relates to a computer system configured to execute the computer program. The invention also relates to a soldering program for a control unit of a soldering system.The invention further relates to a soldering system with a control device which is configured to execute the method, the soldering program and / or the computer program and / or to receive the data carrier signal and execute the instructions.

[0005] The quality of solder joints on a circuit board (PCB) and at least one component to be soldered to it is an essential prerequisite for reliable electronic products. A solder joint is formed between a contact (pin) of the component and the corresponding contact surface of the PCB. A soldering tool is used to heat and melt the solder joint. The solder can be applied to the joint in its liquid state or, in its solid state, brought to the joint and then melted by the tool.

[0006] Different components on a printed circuit board (PCB) have different requirements. In particular, the component's location on the PCB influences how it should be soldered and how the soldering process must be carried out. The temperatures achieved at the solder joint are of paramount importance. These temperatures depend on many factors and influences, especially those related to the components, the PCB, and the soldering tool. If solder joints are soldered too cold, i.e., at too low a temperature, the connections between the pins, the solder, and the contact surface cannot form properly. This is called a cold solder joint. These cold solder joints cannot guarantee proper contact and usually lead to the failure of the electronic components. If solder joints are soldered at too high a temperature, the components themselves or even the PCB can be damaged.

[0007] Soldering processes, especially automated ones, require several manual test soldering runs beforehand and a high level of experience from the operators of the respective soldering systems to achieve the correct temperatures for the solder joints. During this time, the soldering tool or the entire soldering system is occupied. Such a procedure is time-consuming and expensive.

[0008] The present invention is based on the objective of optimizing soldering processes.

[0009] The problem is solved by a method for optimizing soldering processes according to claim 1, in which solder joints are soldered using a soldering tool. The soldering tool can be, for example, a soldering nozzle, laser, or soldering iron, including for hand soldering. The solder joints are provided on the component. The component comprises at least one printed circuit board and at least one component arranged thereon. The method comprises the following steps: a) providing the component's solder parameters; b) providing the soldering tool parameters; c) selecting the solder joints to be soldered; d) specifying a target solder joint temperature to be present during soldering; e) specifying a soldering speed at which the soldering tool is moved over the solder joints or a

[0010] Soldering time, during which the soldering tool remains on each of the solder joints to be soldered; f) Simulating initial actual solder joint temperatures for the individual solder joints to be soldered, taking into account the solder joint parameters, the soldering tool parameters, the target solder joint temperature, and the soldering speed / speed.

[0011] Soldering time; g) Defining a target solder joint temperature range; h) Determining whether the first Ist solder joint temperatures of the individual solder joints simulated according to step f) are within or outside the target solder joint temperature range; and i) Initiating a further step (j, k) if at least one of the simulated first Ist solder joint temperatures is outside the target solder joint temperature range.

[0012] With such a method, the time-consuming and manual trial soldering processes can be eliminated, and the soldering system or workstation is not occupied during the execution of the process. No physical component is required to carry out a step-by-step and iterative optimization process. The actual solder joint temperatures are to be understood as the maximum temperatures reached at the respective solder joints during the soldering process. Furthermore, it is advantageous if, in step c), the solder joints of only one component are initially selected, and the simulation in step f) then only concerns that one component with its respective solder joints and not the entire component to be soldered. Simulations of entire complex assemblies, as in the case of solder components, are also complex, time-consuming, and expensive, just like trial soldering processes, and can be avoided by the method according to the invention.In particular, if a first simulation does not provide usable results, a simulation in the inventive method can be repeated relatively quickly, whereas a simulation of the entire soldering assembly cannot be repeated quickly without further ado.

[0013] It has been found that simulating the solder joints of a single component and determining whether the simulated initial solder joint temperatures are within or outside the specified target solder joint temperature range leads to an optimized soldering process faster and more reliably than previous approaches.

[0014] It is conceivable not to carry out all steps in the process, individual steps can be skipped, or the steps can be carried out in a different order.

[0015] Soldering speed refers to the heating of a soldering joint by the soldering tool as it is moved past it at a specified speed, or by the soldering tool remaining stationary at the joint for a specified duration, thus heating it. An example of soldering speed is a selective soldering nozzle with a solder wave in a soldering module being moved past a joint, where the solder wave is brought into contact with the joint as it passes it. Another example is a soldering system with a stationary solder wave, where the component is then moved past the stationary wave at a specified speed. An example of soldering duration is a soldering iron with a heated tip, where the soldering tip is moved to the joint by a person or a robot during the soldering process.

[0016] Preferably, in step e), a constant soldering speed or the same soldering time is assigned to each solder joint. This further simplifies the simulation in step f).

[0017] In step d), the target solder joint temperature can be set manually or automatically based on the component or other parameters. Since solder joint parameters are already provided, the target solder joint temperature can also be set automatically. If the solder joint parameters are not suitable for automatic setting, or if this does not work for other reasons, the target solder joint temperature can also be set manually.

[0018] Preferably, additional environmental parameters are provided and also taken into account in step f). This results in an improved simulation in step f) and thus better optimized soldering processes. The environmental parameters preferably include parameters of an environment within a soldering system or also of the environment outside the soldering system or a workstation for manual soldering, such as the composition of the atmosphere, the ambient temperature around the workpiece, and parameters for preheating the workpiece.

[0019] The soldering parameters preferably include component parameters such as the geometry and material of the pins, as well as the general geometry of the component itself, including dimensions, material, and thermal mass. The soldering parameters may also include printed circuit board parameters such as the layer stack-up, layer thickness, materials and their thermal properties, the position of the annular rings, the connections of the contacts and vias, various hole positions, geometric dimensions, and properties of the conductor tracks, even at the layer level. The soldering parameters can be contained, for example, in ODB++ and / or Gerber data and / or other data formats.

[0020] The soldering tool parameters preferably include the geometry of a soldering tip of a hand soldering iron, the diameters of a selective soldering nozzle with the inner and outer diameters, the temperature of the hand soldering iron, the temperature of the liquid solder and the composition of the solder with its alloying elements and other materials such as flux and / or the condition of the soldering nozzle or soldering tip.

[0021] In step g), it is conceivable that the target solder joint temperature range is defined around the target solder joint temperature. It is also conceivable that the definition is performed automatically based on the solder material parameters and / or soldering tool parameters, in particular the solder alloy, and / or environmental parameters. It is also conceivable that the definition is performed manually by an operator. From the solder material parameters, the soldering tool parameters, and preferably the environmental parameters, the actual temperature within the entire circuit board is simulated throughout the entire soldering process. When a specific target solder joint temperature is reached, the respective solder joint, for example, a via in the circuit board with the component pin, is considered "soldered."

[0022] It is conceivable that, according to the further step ( ), the soldering speed or soldering time for those solder joints where the simulated initial Ist solder joint temperatures are outside the target solder joint temperature range is modified such that, after at least one further simulation according to step ( f), the subsequent Ist solder joint temperatures of all selected solder joints lie within the target solder joint temperature range. The soldering speed can be modified so that each solder joint has a soldering speed that differs from the specified soldering speed. This modified soldering speed can be lower, i.e., slower, than the specified soldering speed, thereby increasing the Ist solder joint temperature. The modified soldering speed can be higher, i.e., faster, than the specified soldering speed, thereby decreasing the Ist solder joint temperatures.Similarly, longer or shorter adjusted soldering times may result compared to the specified soldering time.

[0023] In other words, the procedure, and in particular steps f) to i) or j), can be described as follows: The initial Ist solder joint temperature at each solder joint is simulated using a fixed soldering speed and / or soldering time of the soldering tool. A ranking of the solder joints is then created based on their initial simulated Ist solder joint temperature. Based on this ranking, the solder joints are assigned a factor that depends on the value of the initial simulated Ist solder joint temperature. The soldering speeds and / or soldering times of the solder joints with the highest and lowest factors are then adjusted so that the subsequent Ist solder joint temperature remains within the target temperature range. All solder joints in between are interpolated according to their respective factors to also achieve an Ist solder joint temperature within the target temperature range.

[0024] It is conceivable that, according to a further step k), the soldering tool parameters and / or the soldering tool with its associated soldering tool parameters are modified for all or those solder joints where the simulated initial actual solder joint temperatures lie outside the target solder joint temperature range, such that, after at least one further simulation according to step f), subsequent actual solder joint temperatures of all selected solder joints lie within the target solder joint temperature range. It is also conceivable to adjust the temperature of the solder and / or the temperature of the soldering iron and / or a preheating temperature of the component being soldered. The soldering tools include, in particular, soldering nozzles and soldering irons. Furthermore, it is conceivable that the tool is adapted, in particular by changing the selection of a soldering nozzle or a soldering iron, especially its tip.It is also conceivable to adjust the angle of the soldering iron to the circuit board when soldering each joint. The target solder joint temperature range preferably lies between a lower temperature limit and an upper temperature limit, with the lower temperature limit preferably being 0.1% to 1% below the target solder joint temperature and the upper temperature limit preferably being 1% to 25% above the target solder joint temperature. Other ranges are conceivable; for example, the lower temperature limit could be 0% to 5% below the target solder joint temperature, or the upper temperature limit could be 0% to 15% above the target solder joint temperature. It is also conceivable that the target solder joint temperature range has no lower temperature limit and, for example, does not allow any deviation below the target solder joint temperature.

[0025] Preferably, in step c), the solder joints on a first component are selected. Preferably, not all solder joints of the component are selected.

[0026] This means that the process is initially carried out on a first component and not on all solder joints of the soldered material.

[0027] However, it is also conceivable to select the solder joints of several components and to carry out the steps of the procedure simultaneously for several components.

[0028] It is conceivable to repeat steps c) to i), steps c) to j), and / or k), with solder joints on a second component being selected in the repeated step c). The solder assembly can comprise several components; however, it is advantageous to perform the procedure stepwise for one component after another until all soldering operations to be optimized are completed for the entire assembly. It is further conceivable to repeat steps c) to i), steps c) to j), and / or k) for all components on the circuit board. It is also conceivable to select the solder joints of several components in step c) and to perform the following steps simultaneously.

[0029] Advantageously, in step f), the simulation is performed only in a simulation area around the respective solder joint. The simulation area preferably does not include the entire solder joint.

[0030] It is advantageous if the simulation of the actual solder joint temperatures according to step f) is performed for the solder joints located on the side of the printed circuit board (PCB) facing away from the soldering tool. Since PCBs have a certain thickness, the soldering tool requires a certain amount of time to heat the solder joint. This is particularly relevant for through-hole components (THT).

[0031] For through-hole technology components, where the pins are inserted through the circuit board, the pins are soldered on the side of the circuit board facing away from the component. This ensures that each solder joint is fully heated and formed, and that the target solder joint temperature is reached throughout the entire joint. If the tool is a soldering nozzle, the solder wave formed by the nozzle is brought into contact with the underside of the circuit board, thus preferably simulating the actual solder joint temperature on the top side of the circuit board.

[0032] It is conceivable that the simulated actual solder joint temperatures of the solder joints could be displayed to a user in such a way that a deviation from the target solder joint temperature is visible, preferably sorted from highest to lowest deviation. The actual solder joint temperatures are preferably also displayed as a function of the target solder joint temperature range, indicating whether they are below or above the target solder joint temperature.

[0033] It is also conceivable to display the new actual solder joint temperatures to the user in such a way that a deviation from the target solder joint temperature can be read, with a particular emphasis on sorting from highest to lowest deviation. The new actual solder joint temperatures are preferably also displayed as a function of the target solder joint temperature range, making it possible to see whether they are below or above the target solder joint temperature.

[0034] It is advantageous if, after step h) or after at least one further step j) and / or k), instructions for soldering are generated and / or output. The generation of these instructions is preferably also based on the position of the solder joints on the printed circuit board, the environmental parameters, the soldering tool parameters, the tool selection, and / or the tool temperature. The instructions generated by the method are preferably usable for automated soldering, in particular in a soldering system with a soldering nozzle or a robot with a soldering iron, and / or for manual soldering, in particular by a person with a hand-held soldering iron.

[0035] The instructions can be generated and / or output as a signal or command to a machine control, as a signal to a data carrier / cloud / storage system and / or as a display on a screen, for example for soldering with a soldering iron or the setup of a soldering system.

[0036] The problem is also solved by a data carrier signal that transmits the instructions generated according to the inventive method. Using these instructions, for example, a soldering system or a robot can execute a soldering process optimized by the inventive method.

[0037] The problem is also solved by a soldering program comprising the instructions generated according to the inventive method, which, when executed by a control unit of a soldering system, cause the soldering program to perform soldering processes in a particularly optimized manner. Thus, the inventive method can be used to generate a soldering program according to which the respective soldering system can be operated. This allows the soldering system to perform soldering processes in a particularly optimized manner. The creation of the soldering program can be carried out at least largely independently and / or automatically using the inventive method.

[0038] The problem is also solved by a computer program comprising commands which, when executed by a computer, cause it to carry out the steps of the inventive method. The computer program thus serves to ultimately carry out the inventive method. In particular, the computer program serves to generate the soldering program for the control unit of the soldering system.

[0039] The problem is also solved by a computer system comprising an input, an output for instructions, and preferably a display, a memory, and an arithmetic unit, wherein the system is configured to execute the computer program. The computer program and / or the computer system allows the method to be carried out independently of the location of the soldering operation. For example, the method can be carried out on a computer in an office without requiring a soldering machine to be stopped during execution, while the soldering machine can perform other soldering operations in the meantime. In particular, the computer system can generate a soldering program according to the invention for the control unit of the soldering machine using the computer program according to the invention.

[0040] The problem is also solved by a soldering system, in particular a selective soldering system, comprising at least one flux module, one heating module and one soldering module and a control device for controlling the flux module, the heating module and / or the soldering module, characterized in that

[0041] - that the control device is set up to carry out the inventive method, in particular to create a soldering program according to the invention and / or,

[0042] - that the control device is set up to execute the computer program according to the invention, in particular to create a soldering program according to the invention

[0043] - that the control unit is set up to execute the soldering program according to the invention, and / or

[0044] - that the control device is set up to receive the data carrier signal according to the invention and to execute the instructions.

[0045] By the inventive method with the

[0046] Soldering processes can be advantageously optimized by considering the data carrier signal, the soldering program, the computer program, the computer system and the soldering equipment.

[0047] 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.

[0048] They show:

[0049] Figure 1: a soldering system;

[0050] Figure 2: a schematic representation of an automated

[0051] Soldering process;

[0052] Figure 3: a schematic representation of a soldering process using a soldering iron;

[0053] Figure 4: a schematic process flow for optimizing soldering processes;

[0054] Figure 5: Selected solder joints of a first component of a solder assembly;

[0055] Figure 6: a detail view from Fig. 5;

[0056] Figure 7: a simulation of a solder joint temperature in a simulation area around a first selected solder joint; Figure 8: a simulation of a solder joint temperature in a simulation area around another selected solder joint;

[0057] Figure 9: first simulated actual solder joint temperatures of the selected solder joints;

[0058] Figure 10: further simulated actual solder joint temperatures of the selected solder joints after a further simulation; and

[0059] Figure 11: a comparison of a first simulated actual solder joint temperature from Fig. 9 and a further simulated actual solder joint temperature from Fig. 10.

[0060] Figure 1 shows a soldering system 10 for soldering components 11. The soldering system 10 can be either a selective soldering system with individual solder pots or a wave soldering system. The components 11 are shown by way of example in Figure 2. 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 can also comprise more or fewer than the three modules 12, 14, 16 shown. For example, two flux modules 12, several heating modules 14, or several soldering modules 16 are conceivable, but not shown. An operating element and a control unit 20 are, for example, arranged in the middle module 14. The modules 12, 14, 16 are interconnected and are preferably controlled by the control unit 20.The control unit 20 can receive data signals and execute computer programs and procedures. It is also conceivable to install modules 12, 14, and 16 individually and in separate locations, for example, at different stations in a production line.

[0061] The diagram shown in Figure 2 is intended to illustrate the basic sequence of a soldering process 26 for soldering a component 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 component 11 is 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 36.1 and a bottom side 36.2. The component 11 moves from left to right through the soldering process 26, as shown in Figure 2.

[0062] Soldering system shown 10 .

[0063] In the first step 28, which is carried out in the soldering system in the flux module 12, flux 42 is applied to the circuit board 36 and the solder joints 44 to be soldered using a movable spray head 38, which has a flux nozzle 40 for applying flux 42. The solder joints 44 to be soldered in this case consist of, on the one hand, the two leads of the component 34, which are inserted through the circuit board 36, and on the other hand, the corresponding contact pads on the circuit board 36. The spray head 38 is movable in the X and Y directions, as indicated by the arrows, so that different areas of the solder joint can be sprayed.

[0064] II can be sprayed with flux 42.

[0065] Subsequently, in the second step 30 of the soldering process 26, the workpiece 11 is heated 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 arranged as top heating above the workpiece 11 and the other heating cassette 46 as bottom heating below the workpiece 11. The heating cassettes 46 emit thermal radiation 48, which is shown schematically as arrows. Step 30 of the heating process can be carried out in the second module 14 of the soldering system shown.

[0066] After preparatory steps 28 and 30, the component 11 is soldered in step 32. The solder joints 44 of the component 11 to be soldered are brought into contact on the underside of the circuit board 36 with liquid solder 50 of a standing wave supplied by a soldering nozzle 52. A movable selective wave soldering nozzle, which solders specific solder joints of the component, is shown as an example soldering tool. However, any other soldering technology can also be used. During the soldering process 26, the soldering nozzle 52 is moved within the soldering module 16 along the component 11 in the XY plane and in the Z direction perpendicular to the XY plane at a soldering speed 54. The soldering speed can vary depending on how long the solder 50 should remain in contact with the solder joint 44 to be soldered in order to properly heat it to a target solder joint temperature and to solder it.Alternatively, the soldering nozzle 52 can also remain at a soldering point 44 for a specified soldering time in order to solder the joint 44. In step 32, it is also conceivable to use a top heating element in the form of a heating cassette 46, as shown in step 30. The required soldering speed 54 or soldering time per soldering point depends on many parameters and the correct setting of the soldering system 10 with regard to these parameters.

[0067] A soldering speed of 54 or a soldering time of that duration requires, in particular, a high level of experience on the part of the operator in soldering systems according to the state of the art. Step 32 can be carried out in the third module 16 of the soldering system shown in Figure 1.

[0068] Figure 3 illustrates a manual soldering process 60. This involves the same solder material 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 nozzle 52. Solder 66, in the form of a wire, is also manually fed to the solder joint. It is possible that the solder is already present at the solder joint in solder deposits on the solder material. The hands 68 are meant to illustrate that the soldering iron 62 and the solder 66 are handled manually by a person. However, it would also be conceivable to handle the soldering iron 62 and the solder 66 using a robot or a soldering iron with an automatic solder feed. 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 has heated up to a target solder joint temperature and the molten solder 66 can spread within the solder joint 44 to form a properly formed solder joint 44 of high quality and durability. The required soldering time when using a soldering iron 62 depends on many parameters and, according to the prior art, requires a high level of experience on the part of the person soldering. Figure 4 schematically shows the method 100 for optimizing previously described soldering processes 26, 60, in which solder joints 44 are soldered to the workpiece 11 using a soldering tool 52, 62. The method 100 comprises the following steps and will be explained in detail with reference to Figures 5 to 11 below.It is possible not to perform all steps, individual steps can be skipped, or the steps can be performed in a different order.

[0069] In a first step, soldering parameters for the solder 11 are provided. These parameters include, in particular, component parameters such as the geometry and material of the pins, as well as the general geometry of the component 34, 34a, including its dimensions, material, and thermal mass. Furthermore, the soldering parameters also include printed circuit board parameters related to the printed circuit board 36, 36a, such as the layer stack-up, the number of layers, the layer thickness, the layer materials and their thermal properties, the position of the annular rings, the connections of the contacts and vias, various hole positions through the layers, geometric dimensions, and properties of the conductor tracks, even at individual layer levels. The soldering parameters are contained, in particular, in ODB++ or in Gerber data or other data formats.

[0070] In the second step 104, soldering tool parameters for the soldering tool to be used are provided. The soldering tool can be of various types, as shown in Figures 2 and 3 above, for example as a soldering nozzle 52 or as a soldering iron 62. The soldering tool parameters include, in particular, the geometry of a soldering tip 64 of a hand soldering iron 62, the diameter of a selective soldering nozzle 52 with its inner and outer diameters, the height of a solder wave formed from liquid solder 50, the temperature of the hand soldering iron 62 and its tip 64, the temperature of the liquid solder 50, the composition of the solder 50, 66, with its alloying elements and other materials such as flux or previously applied flux 42.

[0071] In steps 102 or 104, environmental parameters can also be provided, which are taken into account in the further procedure. The environmental parameters include parameters of an environment within the soldering system 10 or also of the environment outside the soldering system or a workstation for manual soldering, such as the composition of the atmosphere, the ambient temperature around the soldering element 11, and parameters for preheating the soldering element 11 by means of heating cassettes 46. Several solder joints can form a solder path, which the soldering tool traces in one movement.

[0072] The following third step 106 serves to select the solder joints 44 to be soldered for the soldering process to be optimized, as shown in Figures 5 and 6. Figure 5 shows a virtual model of a solder assembly 11a, which comprises a component 34a, a printed circuit board 36a, and selected solder joints 44a. The component 34a is represented as a dashed rectangle to allow the underlying solder joints 44a to be shown. This first component 34a is elongated and extends over most of the length of the printed circuit board 36a. Individual solder joints 44a can be selected based on the component 34a; in this case, they are arranged sequentially along a line. The virtual components 11a, 34a, 36a replicate the physical components 11, 34, 36 shown in Figures 2 and 3 in all properties, so that subsequent results of the method 100 are applicable to a real soldering process 26, 60.A visualization as shown in Figures 5 and 6 can be displayed to an operator of a computer system during the execution of procedure 100. The virtual solder joint 11a with the virtual component 34a and the virtual printed circuit board 36a is based on the previously provided solder joint parameters. The solder joints 44a to be soldered are shown as circles on the printed circuit board 36a. Step 106 can be repeated multiple times for different components, for example, also for component 34 of the solder joint 11 in Figures 2 and 3.

[0073] Figure 6 shows a detailed section of the left area of ​​the solder joint 11a from Figure 5. It is evident that the first four solder joints LI, L2, L3, L4 of the selected solder joints 44a (from left to right) are similar, and the next fifth solder joint L5 differs from the previous ones. Consequently, different solder joints 44a can be present on a single component 34a.

[0074] A subsequent fourth step 108 is the specification of a target solder joint temperature ST (see Figs. 9 and 10), which should be present on the solder joints 44 during the subsequent soldering process. All solder joints 44 should reach this target solder joint temperature ST during soldering, since only when the target solder joint temperature ST is reached can it be ensured that the solder joint 44 fills with solder, an alloy is formed, and the desired fastening and contact of the component 34 with the circuit board 36 is guaranteed.

[0075] The fifth step, 110, then involves specifying a

[0076] Soldering speed at which the soldering tool 52, 62 is to be moved over the solder joints 44, or a soldering time during which the soldering tool 52, 62 remains on the solder joints 44 to be soldered. This specified soldering speed or soldering time is initially constant, in particular for the solder joints 44a selected in step 106.

[0077] After specifying the soldering speed or soldering time duration in step 110, in a sixth step 112, first I st- solder joint temperatures IT (see Fig. 9 and 10 ) are simulated for the individual solder joints 44a to be soldered, taking into account the soldering material parameters, the soldering tool parameters, the target solder joint temperature and the soldering speed / soldering time duration.

[0078] The simulation of these Ist solder joint temperatures IT is shown in Figures 7 and 8, as it can be displayed to an operator of a computer system when carrying out procedure 100. The previously shown virtual solder joint 11a is shown, as are the solder joints 44a. In Figure 7, the first solder joint LI of the solder joints 44a is simulated. The entire solder joint 11a is not simulated; rather, the simulation of the Ist solder joint temperature IT is performed only in a simulation area S around the currently shown solder joint LI in Figure 7 or solder joint LX of the solder joints 44a. This simulation area S can, for example, have an area of ​​11 cm. 2 exhibiting, although larger or smaller areas are also conceivable. For example, the simulation area S on the order of 0.1 x 0.1 cm is conceivable. 2 up to 5x5cm 2to dimension. Such simulation areas S allow adaptation to different solder joints 44a. Upon closer inspection, oval dashed areas of the simulation area S are recognizable, which correspond to temperature gradients TG with different temperatures around the respective solder joint LI, LX.

[0079] Figure 8 shows the simulation of an initial (I) solder joint temperature IT of another solder joint LX of the solder joints 44a within a simulation area S. This simulation proceeds as described above. The initial (I) solder joint temperatures IT of the other solder joints 44a are simulated in the same way until an initial (I) solder joint temperature IT has been simulated for each solder joint 44a. Preferably, the simulation area S is the same size for all solder joints in a simulation process.

[0080] In a subsequent seventh step 114 of method 100, a target solder joint temperature range B is defined, as shown in Figures 9 and 10. The target solder joint temperature range B lies between a lower temperature limit and an upper temperature limit, wherein the lower temperature limit is preferably 0.1% to 1% below the target solder joint temperature and the upper temperature limit is preferably 1% to 25% above the target solder joint temperature ST. Other ranges are conceivable; for example, the lower temperature limit could be 0% to 5% below the target solder joint temperature ST, or the upper temperature limit could be 0% to 15% above the target solder joint temperature ST. It is also conceivable that the target solder joint temperature range B has no lower temperature limit and, for example, does not permit any deviation below the target solder joint temperature ST.

[0081] Figure 9 shows the I st- simulated values ​​obtained by means of the simulation carried out according to step 112.

[0082] Solder joint temperatures IT are shown as maximum values ​​of temperature profiles for all solder joints 44a to be soldered, in particular for the solder joints LI, L2, L3, L4 and L5 shown in Figure 6. The profiles are represented as temperature MT (Y-axis) versus time T (X-axis) in a diagram. Each profile initially rises to a maximum value of temperature MT and then falls again. The maximum value is the actual solder joint temperature IT of the respective solder joint. The target solder joint temperature ST is also shown as a horizontal line. The target solder joint temperature range B shown here begins in the range of the target solder joint temperature ST and includes a temperature range above the target solder joint temperature ST. The lower temperature limit is at or in the range of the target solder joint temperature ST.In this example, a deviation below the target solder joint temperature ST should not be permitted, or only within a range of 1 °C. A deviation above the target solder joint temperature ST is irrelevant in this case and is therefore not limited. However, it is also conceivable to specify an upper temperature limit above the target solder joint temperature ST, particularly when temperature-sensitive components are being soldered.

[0083] Following step 114, an eighth step 116 determines whether the first I st solder joint temperatures IT of the individual solder joints 44a simulated according to step 110 are within or outside the target solder joint temperature range B.

[0084] Figure 9 shows that some of the first simulated

[0085] The solder joint temperatures ITi lie outside the target solder joint temperature range B. These outside solder joint temperatures ITi are below the lower temperature limit, i.e., the target solder joint temperature ST.

[0086] If it is determined that some of the first simulated Ist solder joint temperatures IT2 lie outside the target solder joint temperature range B, a ninth step 118 triggers at least one further step 120, 122. However, if no Ist solder joint temperatures ITst lie outside the target solder joint temperature range B, a step 124 can be executed directly (arrow 126, see Fig. 4), or steps 120 and 122 can be skipped and the preceding steps 106 to 118 repeated for other solder joints (arrows 128 and 130). Step 124 will be explained in more detail later.

[0087] If the first further step 120 is initiated (see arrow 132 in Fig. 4), the soldering speed or soldering time is changed for those solder joints 44a where the simulated first actual solder joint temperatures IT.2 are outside the target solder joint temperature range B. The soldering speed or soldering time of these solder joints 44a is slowed down or lengthened such that, after at least one further simulation performed according to step 112, the resulting further actual solder joint temperatures IT.3, which were previously outside the target solder joint temperature range B, are now all within the target solder joint temperature range B.

[0088] The result of step 120 is shown in Figure 10. Figure 10 shows a diagram corresponding to Figure 9, using the same reference symbols for the same features. Figure 10 clearly shows that none of the actual solder joint temperatures IT are now outside the target solder joint temperature range B. In the subsequent simulation after step 120, the soldering speeds and / or soldering times were specifically reduced or increased for those solder joints where, after the first simulation according to step 112, the actual solder joint temperatures IT.2 were below the target solder joint temperature range B. As a result, all actual solder joint temperatures IT are now within the target solder joint temperature range B, with the higher actual solder joint temperatures compared to Figure 9 being labeled IT.3.It is possible that the soldering speeds or soldering times of the solder joints 44a with actual solder joint temperatures IT, which were not outside the target solder joint temperature range B and are not specifically adjusted, may also undergo slight changes, as these can be influenced by the adjustments of the other solder joints 44a. As an example, the temperature MT curve of solder joint L5 is shown with the further actual solder joint temperature IT.3 (L5), which is now within range B.

[0089] Figure 11 shows a comparison of the temperature profiles and actual solder joint temperatures IT and IT.3 of solder joint L5 from Figures 9 and 10 in a single diagram, using the same reference symbols for the same characteristics. The soldering speed was slowed down or the soldering time increased so that IT.2 (L5) lies within range B.

[0090] As an alternative to step 120 (see arrow 134 in Fig. 4), or additionally in combination with step 120 (see arrow 136), a further step 122 can be performed. In step 122, soldering tool parameters and / or the soldering tool with its associated soldering tool parameters are changed for all or for those solder joints 44a where the simulated first actual solder joint temperatures IT lie outside the target solder joint temperature range B. The soldering tool parameters and / or the soldering tool are changed such that, after at least one further simulation performed according to step 112, the resulting further actual solder joint temperatures IT 3 of all selected solder joints lie within the target solder joint temperature range B. For example, the temperature of the soldering iron, the geometry of a soldering tip, the geometric dimensions of a soldering nozzle, the temperature of the liquid solder of a soldering wave, and / or other parameters can be adjusted.

[0091] After steps 118, 120 and / or 122, the preceding steps can be repeated from step 106 onwards, see arrow 130, whereby in step 106 the solder points 44a are selected using a second component.

[0092] In a final step 124, which can follow steps 118, 120, or 122, instructions 138 for soldering joints 44 to the solder base 11 are generated. These instructions 138 are output in the form of a soldering program 139 and transmitted by a data carrier signal 140, for example, to the control unit 20 of the soldering system. Upon execution of the soldering program 139 or its instructions 138, the control unit causes the soldering system 10 to perform the corresponding soldering operations 26, 60. The soldering program 139 or the associated instructions 138 can be displayed on a screen, particularly for manual soldering, as shown in Fig. 3. By the method 100, soldering operations 26, 60 can be optimized in a simple and time-saving manner, and the quality of soldering of the solder base 11 can be improved. The process 100 is suitable for optimizing both manual soldering processes 60 and automated soldering processes 36 using soldering systems 10.Method 100 is particularly suitable for creating computer programs to control and / or regulate the respective soldering process.

Claims

Patent claims 1. Method (100) for optimizing soldering operations (26, 60) and / or for creating a soldering program (139) with instructions (138) for carrying out soldering operations (26, 60), wherein in the soldering operations (26, 60) solder joints are soldered using a soldering tool, wherein the solder joints (44, 44a) are provided on solder material (11, 11a) and wherein the solder material (11, 11a) comprises at least one printed circuit board (36, 36a) and at least one component (34, 34a) arranged thereon, comprising the following steps: a) providing (102) solder material parameters of the solder material; b) providing (104) soldering tool parameters of the soldering tool (52, 62); c) selecting (106) solder joints (44, 44a) to be soldered; d) Specifying (108) a target solder joint temperature (ST) to be present when soldering the solder joints (44, 44a);e) Specifying (110) a soldering speed (54) at which the soldering tool is moved over the solder joints (44, 44a) or a soldering time during which the soldering tool (52, 62) remains on the solder joints (44, 44a) to be soldered; f) Simulating (112) first actual solder joint temperatures (IT) for the individual solder joints (44, 44a) to be soldered, taking into account the solder joint parameters, the soldering tool parameters, the target solder joint temperature (ST) and the soldering speed (54) / the soldering time; g) Define (114) a target- solder joint temperature range (B); h) Determine (116) whether the first actual solder joint temperatures (IT) of the individual solder joints (44, 44a) simulated according to step f) are within or outside the target solder joint temperature range (B); and i) Initiate (118) a further step (120, 122) if one or more of the simulated first actual solder joint temperatures (IT) are outside the target solder joint temperature range (B).

2. Method (100) according to claim 1, wherein according to the further step (120) the soldering speed (54) or soldering time duration for those solder joints (44, 44a) where the simulated first actual solder joint temperatures (IT) are outside the target solder joint temperature range (B) is changed such that, after at least one further simulation according to step f) (112), the further actual solder joint temperatures (IT, IT.3) of all selected solder joints (44, 44a) resulting are within the target solder joint temperature range (B).

3. Method (100) according to one of the preceding claims, wherein according to a further step (122) the soldering tool parameters and / or the soldering tool (52, 62) with associated soldering tool parameters are changed for all or for those solder joints (44, 44a) where the simulated first actual solder joint temperatures (IT) are outside the target solder joint temperature range (B), such that after at least one further simulation according to step f) (112) the resulting further actual solder joint temperatures (IT, IT.3) of all selected Solder joints (44, 44a) within the target area solder joint temperature range (B) lie.

4. Method (100) according to one of the preceding claims, wherein the target solder joint temperature range (B) lies between a lower temperature limit and an upper temperature limit, wherein the lower temperature limit is preferably 0.1% to 1% below the target solder joint temperature (ST) and the upper temperature limit is preferably 1% to 25% above the target solder joint temperature (ST).

5. Method (100) according to one of the preceding claims, wherein in step c) (106) the solder joints (44, 44a) on a first component (34, 34a) are selected.

6. Method (100) according to any of the preceding claims, wherein steps c) (106) to i) (118) or, according to at least claim 2 and / or claim 3, steps c) (106) to j) (120) and / or k) (122) are repeated, wherein in the repeated step c) (106) solder joints (44, 44a) are selected on a second component.

7. Method (100) according to one of the preceding claims, wherein additional environmental parameters are provided and wherein the environmental parameters are also taken into account in step f).

8. Method (100) according to one of the preceding claims, wherein the simulation (112) of the actual solder joint temperatures (IT) according to step f) (112) is carried out for the solder joints (44, 44a) arranged on the side of the printed circuit board (36, 36a) facing away from the soldering tool (52, 62).

9. Method (100) according to one of the preceding claims, wherein the simulated respective actual solder joint temperatures (IT) of the solder joints (44, 44a) are displayed to a user in such a way that a deviation from the target solder joint temperature (ST) can be read and preferably a sorting from highest to lowest deviation is carried out.

10. Method (100) according to any of the preceding claims, wherein after step i) (118) or according to any of claims 2 and / or 3 after at least one further step j) (120) and / or k) (122) instructions (138) for soldering are generated and / or output.

11. Data carrier signal (140) that transmits the instructions (138) according to claim 10.

12. Soldering program (139) comprising instructions (138) according to claim 10 which, when the soldering program (139) is executed by a control device (20) of a soldering system (10), cause it to perform soldering operations.

13. Computer program comprising instructions which, when the program is executed by a computer, cause it to perform the steps (102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124) of the method (100) according to any one of claims 1 to 10.

14. Computer system comprising an input, an output, a memory and a computing unit, wherein the system is configured to execute the computer program according to claim 12.

15. Soldering system (10), in particular a selective soldering system, comprising at least one flux module (12), a heating module (14) and a soldering module (16) and a control unit (20) for controlling the flux module (12), the heating module (14) and / or the soldering module (16), characterized in that, - that the control device (20) is configured to execute the method (100) according to one of claims 1 to 10 and / or, - that the control device (20) is configured to execute the computer program according to claim 13, and / or - that the control device (20) is configured to execute the soldering program according to claim 12, and / or - that the control device (20) is configured to receive the data carrier signal (140) according to claim 11 and to execute the instructions (138) according to claim 10.

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