Replacement of feeding devices

Abstract

The exchange of feeders on a pick-and-place machine is carried out automatically according to a new protocol in which a partially emptied feeder is temporarily moved from its slot to an external storage location, a full replacement feeder is inserted into its slot, and the partially emptied feeder is returned to a spare slot on the pick-and-place machine from which its remaining components are taken.

Description

[0001] The invention relates to a method for supplying a placement machine with SMT components within feeder modules during an SMT placement process and to a method for replacing emptied feeder modules on a placement machine during an SMT placement process. Background and state of the art

[0002] The present invention relates generally to the technical field of equipping component carriers, such as printed circuit boards (PCBs), substrates or workpieces, with electronic components in a so-called Surface Mount Technology (SMT) process.

[0003] The production of electronic assemblies is typically carried out using so-called placement machines, which automatically remove electronic components from a component supply device and place them on a component carrier, such as a printed circuit board. The transfer of the components from the component supply device to their respective placement position is carried out by a handling device, for example, a so-called placement head. In most cases, such a transfer of a component is carried out using a single handling device, which is usually referred to as a placement head.

[0004] The most common packaging for small electronic components uses carrier tapes, sometimes called "belts," into which small pockets are formed. A component is provided in each of these pockets. Each carrier tape contains only one type of component. To save space and facilitate transportation, the carrier tapes are usually wound as spools on a reel. Typically, the tape spool is placed in a feeder module (usually simply called a "feeder") that contains drive means for advancing the tape, such as a motor-driven pin wheel that engages holes provided along the length of the carrier tape, and a receiving area or window that provides access to the components. The feeder can be removably inserted into a pick and place machine.The pick and place machine is provided with a number of parallel slots or tracks, each slot configured to releasably receive a feeder. In this way, a pick and place machine can be equipped with a plurality of different feeders, each feeder capable of supplying the pick and place machine with a specific component.

[0005] More recently, a cartridge system has been proposed in which a tape reel is placed in a passive cartridge module or cassette, which is conveniently a relatively inexpensive plastic container or sleeve with a defined shape that can be easily held by a robot, loaded at a central feed station, and subsequently connected to a feed module containing drive means for advancing the tape reel. Alternatively, if the pick-and-place machine itself is equipped with tape drive mechanisms, the cartridge module could be inserted directly into the pick-and-place machine along a slot. An example of a cartridge-feeder arrangement is described, for example, in DE 10 2019 127 299 A1.In such systems, the feeder can be used to drive the carrier tape located in a cartridge unit so that components located in pockets of the carrier tape are moved to a removal area where a placement head of a pick-and-place machine can access the components. Depending on the design, the removal area can be located inside the cartridge or inside the feeder.

[0006] For the operation of the placement machine, it is necessary that feeding devices (and / or cartridges depending on the design) including the corresponding carrier tapes can be fed to the placement machine.

[0007] Such conversion (i.e. the installation of different feeders / cartridges) is currently a manual process that requires a high level of personnel effort.

[0008] In today's common manual refill process, known as "splicing," the carrier tape from which the component is removed by the placement machine is manually spliced ​​to a new tape. The old tape is unwound from its spool, spliced ​​to the new carrier tape, and wound onto the new spool.

[0009] This process allows refilling to occur before it's needed. Refilling doesn't have to occur at a precise time, but rather within a specific period of time. This period is calculated and monitored by software such as the Siplace Line Monitor. This ensures a certain degree of decoupling of the processes, creating a continuous order flow for the refilling or filling process. This allows peaks and lulls in demand to balance each other out to a certain extent.

[0010] In recent years, significant efforts have been made to automate the replenishment and changeover of materials.

[0011] Specific prior art includes EP 3 419 402 A1. As described in this document, an external transfer device may be provided for transferring a feeding device, which includes both the ability to feed and store material, between a storage location and an operating location. The transfer device is operable to move along a production line with one or more pick-and-place machines parallel to the direction of workpiece throughput. The transfer device is movable along and supported by a rail mounted on the production line (it is therefore also referred to as a "rail-mounted vehicle").Such an approach has several advantages. For example, the use of a machine-mounted rail avoids any problems that can arise from uneven floor surfaces, as the changer is held in a fixed vertical position relative to the pick-and-place machines. Furthermore, high positioning accuracy along the production line is possible. One advantage of such a system is that the rail-guided vehicle can draw power directly and potentially continuously from the pick-and-place machine. However, there are several disadvantages associated with such a system. For example, it requires a separate changer for each side of the production line, which can limit the placement of adjacent lines. The described system also lacks flexibility and cannot, for example, handle cartridge-based feeding systems.The system has been shown to be relatively slow and expensive due to the high demand for special equipment for each production line.

[0012] It was recognized that a more flexible and potentially cost-effective solution could be to equip an automated guided vehicle (AGV) with a cartridge feeder / exchange mechanism. As is well known in the art, AGVs are small mobile robots that typically move across a floor using a wheeled chassis and possess at least some degree of autonomy. AGVs are available from many manufacturers (and are therefore relatively inexpensive, with the likelihood that a production line operator already has suitable AGVs) and are typically equipped with an upper platform capable of supporting job-specific equipment.

[0013] Such approaches enable automated or automatic replenishment by exchanging the feeder instead of the manual splicing method described above. In such automated processes, the tape and reel are stored and transported within the feeder. An automatic handling system handles the feeder directly, with the reel located within the feeder. In contrast to the manual splicing process, where reels and tape are handled separately, an automated process allows a constant and defined interface of the feeder to be used for handling, simplifying handling. An essential component of the automatic handling system is the exchange mechanism, which enables the transfer of the feeders between the pick and place machine and a separate storage area.

[0014] To refill material on a pick-and-place machine, a feeder is pulled out of its lane within the machine by an automatic handling system / exchange mechanism, and a new feeder replaces the old one in the same slot. To ensure that all components of a tape are used, a slot should not be refilled until all components of a feeder have been removed from the pick-and-place machine. This means that subsequent refilling on the same lane (as is possible in a manual splicing process) is no longer possible.

[0015] In such an automated process, there are two main causes of machine downtime during which a removal cannot be carried out: i) First, no component can be picked up by a feeder belonging to a track while the feeders for that track are being replaced. This downtime can be minimized by faster feeder replacement. ii) In addition, downtime may occur if the automatic handling system fails to replace the feeder on a lane in a timely manner, i.e. too late, so that the feeder runs out of components before the replacement. This can happen, for example, when several feeders (either on a pick and place machine or on a production line with one or more pick and place machines) are emptied at the same time. In this case, the feeders can only be replaced one after the other, provided there is only a single automatic handling system on the line. Providing additional automatic handling machines on a line can reduce this type of downtime, however, this problem can still occur if more than two feeders are emptied at the same time.In addition, the provision of additional automatic handling machines significantly increases the costs for the production line operator.

[0016] There are various initiatives to minimize downtime through automated processes. For example, EP 4 277 447 A1 by the present applicant, as well as US 11 464 145 B2 and WO 2020 / 039 543 A1, describe methods in which the new or replacement feeder (second feeder) is placed on a spare lane (reserve lane) within the same pick-and-place machine. After the first feeder no longer contains components, the machine can remove components from the second feeder. This type of method can significantly reduce downtime and, if implemented correctly, prevent machine downtime.

[0017] Such a process is schematically shown in the Fig. 1A - 1F.

[0018] Fig. Figure 1A shows a pick-and-place machine 1 with a pick-and-place head 2, which can pick components from feeder modules located in any slots of the pick-and-place machine 1. Five slots are shown here—in practice, there are usually many more than these. Of these five slots, three slots, 3A, 3B, and 3C, are "preferred slots," which are well-positioned for an efficient pick-and-place operation, while slots 4A and 4B are "spare slots" (reserve slots), which are poorly positioned and therefore lead to inefficiencies in a pick-and-place operation when components are picked by a feeder in such a spare slot.If, for example, workpieces (not shown) that are subjected to a placement process pass through the placement machine 1 in a transport direction T, the placement location of these workpieces within the placement machine 1 can be close to the slots 3A-3C, so that the removal from feeders in the spare slots 4A, 4B would require an additional travel path and an associated additional travel time of the placement head 2 between the feeder module and the workpiece.

[0019] The position of the placement head 2 next to slot 3C indicates that the removal is currently being performed by a feeder module, i.e., a first feeder module "A," located in this slot. The first feeder module A has sufficient components, i.e., they have not yet been depleted by the placement process to the extent that refilling is necessary or desirable.

[0020] Fig. Figure 1B shows the start of a refilling operation, which is triggered when the first feeder module A reaches a predefined level of emptying, illustrated by the diagonal line across the first feeder module A. At this time, a mobile robot 5 is sent to the pick-and-place machine 1 and orients itself near the slots 3A-C, 4A, B. The mobile robot 5 comprises a storage 6 for temporarily storing at least two feeder modules. The storage 6 is movable relative to the base of the mobile robot 5 along an axis X which, when the mobile robot 5 is positioned to engage the pick-and-place machine 1, is generally parallel to the transport direction T. This relative movement makes it possible to orient the storage 6, and thus the stored feeder modules, parallel to the transport direction T, relative to the slots 3A-C, 4A, 4B as needed.

[0021] It should be noted that there are other ways to achieve such alignment between the stored feeder modules and the slots 3A-C, 4A, 4B. For example, the mobile robot 5 itself may be capable of moving precisely along the X-axis; in this case, no relative movement of the storage 6 is required. Alternatively, an exchange mechanism (see below) may be provided that is capable of moving the feeder modules parallel to the X-axis during transfer between the storage 6 and the pick-and-place machine 1.

[0022] As in Fig. 1B, the store 6 comprises a plurality, here three, of store slots 7A-C, each store slot 7A-C being configured to removably receive a feeder module in use. As shown, a second feeder module B is received in the store slot 7B - this second feeder module B contains the same type of component as the first feeder module A. The store 6 is aligned with the pick and place machine 1 such that the store slot 7B is aligned with a spare slot, in this case 4B. If necessary, the store 6 is moved along the X-axis to achieve this alignment (not shown). During this phase, removal by the pick and place head 2 continues from the first feeder module A.

[0023] As in Fig. 1C, the second feeder module B is then transferred from the storage slot 7B to the spare slot 4B by an exchange mechanism 8. The exchange mechanism 8 is not shown in detail in the figures, but comprises a mechanical interface capable of transferring feeder modules horizontally and orthogonally to the X-axis between the storage 6 and the pick-and-place machine 1 in both directions, for example by engaging a profiled portion of the feeder module. A simple exchange mechanism 8 may, for example, comprise a paddle capable of engaging a recess provided on a feeder module, the paddle being attached to a drive belt that can be driven in both directions, thus pushing or pulling the feeder module linearly between the storage 6 and the pick-and-place machine 1.Exemplary exchange mechanisms are described, for example, in DE 10 2021 117 281 B3, DE 10 2021 119 314 B3, and EP 4 346 346 A1. The exchange mechanism 8 can be located on the mobile robot 5, on the placement machine 1, or as a separate unit. During this phase, the removal by the placement head 2 from the first feeder module A continues until the first feeder module A is completely empty.

[0024] As in Fig. 1D, when the first feeder module A is completely empty (as shown by the two crossed lines in the feeder module A), the pick and place head 2 starts removing components from the second feeder module B on the spare slot 4B.

[0025] As in Fig. As shown in Figure 1E, the mobile robot 5 is then sent to the pick-and-place machine 1. The storage 6 is moved along the X-axis so that an empty storage slot, here 7B, is aligned with slot 3C. During this phase, the pick-and-place head 2 continues to pick parts from the second feeder module B.

[0026] As in Fig. As shown in Figure 1F, the exchange mechanism 8 then transfers the empty first feeder module A from slot 3C to the memory slot 7B. During this phase, the removal by the pick-and-place head 2 from the second feeder module B continues.

[0027] As you can see, during the steps in the Fig. 1D to 1F, the placement head 2 removes the component from the second feeder module B while it is located in the spare slot 4B. This is a disadvantage of such methods. Typically, the feeders at the individual slots are carefully selected to optimize the placement speed, so that, for example, components that are placed in large numbers on a board can be placed in slots located a short distance from the nominal "home position" of the placement head, thereby minimizing the travel time of the placement head 2. If the feeder is instead located in a spare slot, its location is obviously not as optimal.

[0028] This lack of optimization can be remedied by subsequently moving the second feeder module B to the optimal slot, i.e. to the original location of the first feeder module A (here slot 3C), as soon as the first feeder module A is empty. This is described in the Fig. 1G - 1J. As will become clear from the following description, this movement requires downtime during which no component associated with the feeder module can be removed. There is at least some flexibility regarding the timing of the movement, so it may be possible to perform it at a relatively convenient time, reducing the impact on throughput, but this downtime is nevertheless unavoidable.

[0029] As in Fig. As shown in Figure 1G, the memory 6 moves along the X-axis, to the left as shown, until an empty memory slot, here 7C, is aligned with the spare slot 4B. During this phase, removal by the pick-and-place head 2 from the second feeder module B continues.

[0030] As in Fig. 1H, the exchange mechanism 8 then transfers the second feeder module B into the slot 7C of the storage 6. During this phase, no removal can take place.

[0031] As in Fig. As shown in Figure 1l, the storage 6 moves to the right along the X-axis, as shown, until the storage slot 7C is aligned with the slot 3C. The exchange mechanism 8 can then transfer the second feeder module B into the slot 3C. During this phase, no removal can occur.

[0032] Finally, the placement head 2 can be moved as shown in Fig. 1J, begin again with the removal from the second feeder module B in slot 3C. The mobile robot 5 can move freely and deliver the empty first feeder module A to a collection station (not shown) for refilling at the appropriate time.

[0033] US 2016 / 0 192 546 A1 discloses a system in which feed devices for electronic components can be automatically distributed at different positions along a placement line with a plurality of placement devices arranged one behind the other along a transport path for substrates.

[0034] US 2022 / 0 104 411 A1 discloses a placement system with a plurality of placement devices and a management device with which feed devices for electronic components can be automatically redistributed along the placement system.

[0035] The object of the present invention is to provide an automatic replenishment system and method which minimizes downtime and yet can be operated with an economically viable number of automatic handling machines or exchange units.

[0036] According to the invention, this goal is achieved by a new method for exchanging emptied feeder modules and thus for supplying a placement machine with SMT components in feeder modules. Summary of the invention

[0037] According to a first aspect of the present invention, a method is provided for supplying a pick and place machine with SMT components within feeder modules during an SMT placement operation, wherein the pick and place machine comprises a plurality of slots, each slot being configured to releasably receive a feeder module in use, and wherein a first slot of the plurality of slots has a first feeder module received therein, which contains a plurality of SMT components and which is emptied during the SMT placement operation, the method comprising the steps of: i) providing an exchange unit, the exchange unit comprising a storage for temporarily storing at least two feeder modules, the storage being provided with a second feeder module containing the same type of SMT components as the first feeder module, ii) transferring the first feeder module from the first slot to the storage before the first feeder module is completely emptied of SMT components, iii) transferring the second feeder module from the memory to the first slot, and iv) transferring the first feeder module from memory to a second slot of the plurality of slots of the pick and place machine.

[0038] According to a second aspect of the present invention, there is provided a method for replacing emptied feeder modules on a pick and place machine during an SMT placement operation, wherein the pick and place machine comprises a plurality of slots, each slot being configured to releasably receive a feeder module in use, and wherein a first slot of the plurality of slots has a first feeder module received therein containing a plurality of SMT components and which is emptied during the SMT placement operation, the method comprising the steps of: i) providing an exchange unit, the exchange unit comprising: a storage for temporarily storing at least two feeder modules, the storage being provided with a second feeder module containing the same type of SMT components as the first feeder module, ii) transferring the first feeder module from the first slot to the storage before the first feeder module is completely emptied of SMT components, iii) transferring the second feeder module from the memory to the first slot, and iv) transferring the first feeder module from the memory to a second slot of the plurality of slots of the pick and place machine.

[0039] Further specific aspects and features of the present invention are set forth in the appended claims.

[0040] For the purposes of the present invention, the term “feeder module” means either: (a) a feeding device, ie a single module carrying a component tape reel and a drive means for advancing the tape reel, or b) a cartridge module carrying a component tape reel but no drive means, for engagement either with a separate feed module or directly with a pick-and-place machine incorporating tape drive means.

[0041] The term “mobile robot” as used herein includes automatically guided vehicles (AGVs), rail-guided vehicles (RGVs), which, as described above, are mobile robots that move along a rail carried by or in proximity to a pick-and-place machine, autonomous intelligent vehicles (AIVs), and the like. Short description of the drawings

[0042] The invention will now be described with reference to the accompanying drawings (not to scale), in which: Fig. 1A-J schematically show the steps of a known method for exchanging feed devices; and Fig. 2A-J schematically show the steps of a method for exchanging feeder modules according to the present invention. Detailed description of the preferred embodiments of the invention

[0043] The Fig. 2A-J schematically show the steps of a method for exchanging feeder modules according to the present invention. A similar device can be used as described above with reference to Fig. 1A-J, and so the corresponding reference numerals are used again for simplicity.

[0044] Fig. Figure 2A shows a placement machine 1 with a placement head 2, which can pick components from feeder modules located in any slots of the placement machine 1. Five slots are shown here—in practice, there are usually many more than this. Of these five slots, three slots, 3A, 3B, and 3C, are "preferred slots," which are well positioned for an efficient placement process, while slots 4A and 4B are "spare slots" (reserve slots), which are not well positioned and therefore lead to inefficiencies in a placement process when components are picked by a feeder in such a spare slot.If, for example, workpieces (not shown) that are subjected to a placement process pass through the placement machine 1 in a transport direction T, the placement location of these workpieces within the placement machine 1 can be close to the slots 3A-3C, so that the removal from feeders in the spare slots 4A, 4B would require an additional travel path and an associated additional travel time of the placement head 2 between the feeder module and the workpiece.

[0045] The position of the placement head 2 next to slot 3C indicates that the removal is currently being performed by a feeder module, i.e., a first feeder module "A," located in this slot. The first feeder module A has sufficient components, i.e., they have not yet been depleted by the placement process to the extent that refilling is necessary or desirable.

[0046] Fig. Figure 2B shows the start of a refilling process, which is triggered when the first feeder module A reaches a predefined emptying level, illustrated by the diagonal line across the first feeder module A. There are several methods by which the predefined emptying level of the feeder module A can be determined. For example: i) A run-down time can be determined for the first feeder module A, after which the first feeder module A is completely emptied of SMT components. The predefined level of emptying can then be defined as the level of emptying that occurs after a predefined portion of the specified run-down time. For example, if the predefined level of emptying is set to occur after 70% of the run-down time, and the run-down time for a feeder module is determined to be 10 minutes, then the predefined level of emptying occurs after 7 minutes. At this time, the refill process is triggered.The run-out time for the feeder module A can be determined, for example, by knowing the initial number of SMT components held by the feeder module A and analyzing the use of those SMT components during a placement operation by counting the number of SMT components removed, or by analyzing the number of SMT components required for each workpiece to be placed and counting the number of workpieces so placed; or. ii) the number of SMT components remaining in the first feeder module A can be determined, and the predefined degree of emptying is set when the number of remaining SMT components stored in the feeder module A falls below a predetermined number. Again, the number of SMT components remaining in the first feeder module A can be determined by knowing the initial number of SMT components stored in the feeder module A and analyzing the use of those SMT components during a placement operation by counting the number of SMT components removed, or by analyzing the number of SMT components required for each workpiece to be placed and counting the number of workpieces thus placed.The replenishment process is initiated when the determined number of SMT components remaining in the first feeder module is below a threshold.

[0047] At this point, a mobile robot 5, which in this embodiment represents the exchange unit, is sent to the pick-and-place machine 1 and orients itself near the slots 3A-C, 4A, B. The mobile robot 5 comprises a storage 6 for temporarily storing at least two feeder modules. The storage 6 is movable relative to the base of the mobile robot 5 along an axis X which, when the mobile robot 5 is positioned to engage the pick-and-place machine 1, is generally parallel to the transport direction T. This relative movement makes it possible to orient the storage 6, and thus the stored feeder modules, parallel to the transport direction T, relative to the slots 3A-C, 4A, 4B as needed.

[0048] It should be noted that there are other ways to achieve such alignment between the stored feeder modules and the slots 3A-C, 4A, 4B. For example, the mobile robot 5 itself may be capable of moving precisely along the X-axis; in this case, no relative movement of the storage 6 is required. Alternatively, an exchange mechanism (see below) may be provided that is capable of moving the feeder modules parallel to the X-axis during transfer between the storage 6 and the pick-and-place machine 1.

[0049] As in Fig. 2B, the store 6 comprises a plurality, here three, of store slots 7A-C, each store slot 7A-C being configured to removably receive a feeder module in use. As shown, a second feeder module B is received in the store slot 7B - this second feeder module B contains the same type of component as the first feeder module A. The store 6 is aligned with the pick and place machine 1 such that an empty store slot, here the store slot 7C, is aligned with the slot 3C in which the first feeder module A is located. If necessary, the store 6 is moved along the X-axis to achieve such alignment (not shown). During this phase, removal by the pick and place head 2 continues from the first feeder module A.

[0050] As in Fig. 2C, the first feeder module A is then transferred from slot 3C to storage slot 7C by an exchange mechanism 8. The exchange mechanism 8 is not shown in detail in the figures, but comprises a mechanical interface capable of transferring feeder modules horizontally and orthogonally to the X-axis between the storage 6 and the pick-and-place machine 1 in both directions, for example by engaging a profiled portion of the feeder module. A simple exchange mechanism 8 may, for example, comprise a paddle capable of engaging a recess provided on a feeder module, the paddle being attached to a drive belt that can be driven in both directions, thus pushing or pulling the feeder module linearly between the storage 6 and the pick-and-place machine 1.Exemplary exchange mechanisms are described, for example, in DE 10 2021 117 281 B3, DE 10 2021 119 314 B3, and EP 4 346 346 A1. The exchange mechanism 8 can be located on the mobile robot 5, on the placement machine 1, or as a separate unit. During this phase, removal by the placement head 2 is not possible.

[0051] As in Fig. As shown in Figure 2D, the storage 6 is moved along the X-axis so that the storage slot 7B, which stores the full second feeder module B, is aligned with the now empty slot 3C. During this phase, no removal by the pick-and-place head 2 is possible.

[0052] As in Fig. As shown in Figure 2E, the exchange mechanism 8 then transfers the full second feeder module B from the memory slot 7B to slot 3C. During this phase, no removal by the placement head 2 is possible until the second feeder module B has been completely transferred to slot 3C.

[0053] As in Fig. As shown in Figure 2F, the storage 6 is moved along the X-axis so that the storage slot 7C, which stores the partially emptied first feeder module A, is aligned with a spare slot, in this case 4B, which allows for slightly more economical removal than the other spare slot 4A. During this phase, removal by the pick-and-place head 2 can be continued from the second feeder module B, if necessary.

[0054] As in Fig. As shown in Figure 2G, the exchange mechanism 8 then transfers the partially emptied first feeder module A from the storage slot 7C to the spare slot 4B. During this phase, the removal by the pick-and-place head 2 from the second feeder module B continues.

[0055] As in Fig. As shown in Figure 2H, the pick-and-place head 2 can resume picking from the first feeder module A in the spare slot 4B. The mobile robot 5 can move freely as needed.

[0056] As in Fig. As shown in Figure 2l, once the first feeder module A is completely emptied (as shown by the two crossed lines in the feeder module A), the pick and place head 2 can resume picking from the second feeder module B in slot 3C.

[0057] Finally, as in Fig. 2J, the mobile robot 5 is moved to a position near the pick and place machine 1 and the storage 6 is moved along the X-axis so that an empty storage slot, in this case 7C, is aligned with the spare slot 4B. The exchange mechanism 8 then transfers the empty first feeder module A from the spare slot 4B to the storage slot 7C. During this phase, removal by the pick and place head 2 from the second feeder module B continues. The mobile robot 5 can move away as needed and deliver the empty first feeder module A to a collection station (not shown) for refilling at an appropriate time. This step can be performed whenever convenient - since the second feeder module B still has a good fill level, there is no immediate urgency to collect the empty first feeder module A.This means that mobile robot 5 is available for other, perhaps more urgent, tasks in the meantime.

[0058] It is evident that the present method has several advantages over the Fig. 1 shown earlier method offers: - The mobile robot can perform a replenishment task before a feeder module runs out of components. This reduces the time dependency and lowers the power requirements for replenishment. Simulations have shown that for smartphone customers with lines with eleven pick-and-place machines, two robots are required to complete all replenishment tasks in a timely manner using the previous method, which involves timely feeder replacement. With this method, the number of robots has been reduced to one. - The reduced time dependency makes the replenishment process more robust against disruptions to automated handling and production flow. An example of such a disruption is the replacement of two feeders within a short period of time, requiring a forecast to decide which feeder should be replaced first. However, disruptions such as picking errors can cause the forecast to be incorrect. A mobile robot can therefore be sent to the wrong location, resulting in longer machine downtimes. The same applies to disruptions that affect the replenishment process, for example, the presence of people in the aisle; - The lower time dependence allows a reduction in the prediction accuracy of the feeder module replacement events; - The mobile robot is released from the line; as more spare lanes are used on the line, the mobile robot gains a larger block of “idle time” that can be used to support tasks on other lines, for changeovers, battery recharging, etc.; and - Compared to the previous method, the period during which the track is unavailable is shorter.

[0059] The embodiments described above are merely exemplary, and other possibilities and alternatives within the scope of the invention will be apparent to those skilled in the art. For example, multiple steps may be combined. For example, the mobile robot may pick up empty feeders that may be located in other spare slots, such as those emptied during a previous refilling operation, simultaneously with, or immediately before or after, transferring the partially emptied first feeder module to the spare slot.

[0060] In the embodiments described above, the exchange unit comprised a mobile robot with a storage unit. However, the invention is not limited thereto, and other types of exchange units, each comprising a storage unit, may also be used. For example, exchange units are known that are stored at least temporarily at the pick-and-place machine. Such exchange units can be placed at the pick-and-place machine by a mobile robot, which can move away while the exchange unit performs the required transfer of feeder modules, or they can travel alongside pick-and-place machines as needed (such as so-called "rail-guided vehicles"), or they can simply be placed next to a pick-and-place machine, possibly by a human operator (similar to the known shuttle tables).In all cases, the exchange mechanism can be provided either as part of the exchange unit, as part of the placement machine or as a separate unit. Reference symbols used: 1 assembly machine 2 placement heads 3A-C Preferred slots 4A, B spare slots 5 Mobile Robot 6 storage 7A-C memory slots 8 Exchange mechanism 9 storage conveyors A First feeder module B Second feeder module T Transport direction X Horizontal axis

Claims

[1] A method for supplying a placement machine (1) during an SMT placement process with SMT components within feeder modules (A, B), wherein the placement machine (1) has a plurality of slots (3A-C, 4A, 4B), each slot (3A-C, 4A, 4B) being configured to releasably receive a feeder module (A, B) in use, and wherein a first slot (3C) of the plurality of slots (3A-C, 4A, 4B) has a first feeder module (A) received therein, which contains a plurality of SMT components and which is emptied during the SMT placement process, the method comprising the steps of: i) providing an exchange unit, the exchange unit comprising a storage (6) for temporarily storing at least two feeder modules (A, B), the storage (6) being provided with a second feeder module (B) containing the same type of SMT components as the first feeder module (A), ii) starting a refilling process in which the first feeder module (A) is transferred from the first slot (3C) to the storage (6) before the first feeder module (A) is completely emptied of SMT components, iii) continuing the refilling process by transferring the second feeder module (B) from the store (6) to the first slot (3C), and iv) transferring the first feeder module (A) from the memory (6) to a second slot (4B) of the plurality of slots of the pick and place machine (1). [2] The method of claim 1, wherein step i) comprises providing an exchange mechanism (8) operable to transfer a feeder module (A, B) from one slot (3A-C, 4A, 4B) of the plurality of slots (3A-C, 4A, 4B) of the pick and place machine (1) to the storage (6) and to transfer a feeder module (A, B) from the storage (6) to one slot (3A-C, 4A, 4B) of the plurality of slots (3A-C, 4A, 4B) of the pick and place machine (1), and wherein in steps ii), iii) and iv) the first and second feeder modules (A, B) are transferred by the exchange mechanism (8). [3] The method of claim 2, wherein the memory (6) comprises a plurality of memory slots (7A-7C), each memory slot (7A-7C) being configured to releasably receive a feeder module (A, B) in use, and wherein the exchange mechanism (8) is operable to transfer a feeder module (A, B) from a slot (3A-C, 4A, 4B) of the plurality of slots (3A-C, 4A, 4B) of the pick and place machine (1) to a memory slot (7A-7C) and to transfer a feeder module (A, B) from a memory slot (7A-7C) to a slot (3A-C, 4A, 4B) of the plurality of slots (3A-C, 4A, 4B) of the pick and place machine (1). [4] Method according to one of claims 2 and 3, wherein the exchange unit comprises the exchange mechanism (8). [5] Method according to one of claims 2 and 3, wherein the placement machine (1) comprises the exchange mechanism (8). [6] The method according to any one of claims 1 to 5, wherein step iii) comprises using a placement head (2) of the placement machine (1) to remove SMT components from the second feeder module (B) in the first slot (3C). [7] Method according to one of claims 1 to 6, comprising the step: v) Using a placement head (2) of the placement machine (1) to remove SMT components from the first feeder module (A) in the second slot (4B). [8] A method according to claim 7, comprising the step: vi) when the first feeder module (A) is completely empty of SMT components, using the pick and place head (2) of the pick and place machine (1) to remove SMT components from the second feeder module (A) in the first slot (3C). [9] A method according to claim 8, comprising the step: vii) Transferring the completely emptied first feeder module (A) from the second slot (4B) to the storage (6). [10] The method of any one of claims 1 to 9, wherein step ii) comprises determining a run-out time for the first feeder module (A) at which the first feeder module (A) is completely emptied of SMT components, and starting the refilling process within a predefined sub-range of the determined run-out time. [11] The method of any one of claims 1 to 9, wherein step ii) comprises determining the number of SMT components remaining in the first feeder module (A) and initiating the refilling operation when the determined number of SMT components remaining in the first feeder module (A) is below a threshold value. [12] Method according to one of claims 1 to 11, wherein the exchange unit comprises a mobile robot (5). [13] The method according to claim 12, wherein the mobile robot (5) comprises one of the following groups: automatically guided vehicles, rail-guided vehicles, autonomous intelligent vehicles. [14] Method according to one of claims 1 to 13, wherein the feeder module (A, B) comprises a feeder. [15] Method according to one of claims 1 to 13, wherein the feeder module (A, B) comprises a cartridge module. [16] A method for exchanging emptied feeder modules (A, B) on a placement machine (1) during an SMT placement process, the placement machine (1) comprising a plurality of slots (3A-C, 4A, 4B), each slot (3A-C, 4A, 4B) being configured to releasably receive a feeder module (A, B) in use, and a first slot (3C) of the plurality of slots having a first feeder module (A) received therein, containing a plurality of SMT components and being emptied during the SMT placement process, the method comprising the steps of: i) providing an exchange unit, the exchange unit comprising: a storage (6) for temporarily storing at least two feeder modules (A, B), the storage (6) being provided with a second feeder module (B) containing the same type of SMT components as the first feeder module (A), ii) transferring the first feeder module (A) from the first slot (3C) to the storage (6) before the first feeder module (A) is completely emptied of SMT components, iii) transferring the second feeder module (B) from the memory (6) to the first slot (3C), and iv) transferring the first feeder module (A) from the memory (6) to a second slot (4B) of the plurality of slots (3A-C, 4A, 4B) of the pick and place machine (1).

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