Production control equipment

Abstract

This production management device is provided with: a calculation unit that, after repeated execution of a mounting operation for mounting on a substrate a component supplied by a component supply unit in which a component housing member is replaceably set in a component mounting apparatus, calculates the error rate of the mounting operation for each prescribed time period divided by a time including at least a component housing member replacement time; and an estimation unit for using the error rate for each prescribed time period to estimate whether a portion causing an error is in the component supply unit or the component housing member.

Description

Technical Field

[0001] This specification relates to a production management device for a component mounting machine that performs a component mounting operation using a component supply unit.

Background Art

[0002] Techniques for mass-producing substrate products by performing production operations in multiple processes on a substrate with a circuit pattern formed thereon have become widespread. As a representative example of a substrate production work machine that performs production operations, there is a component mounting machine that executes a mounting operation for mounting components on a substrate. Generally, a component mounting machine supplies components using a component supply unit in which a component storage member is set to be replaceable, and causes a component mounting tool to perform a mounting operation. In this type of component mounting machine, an error that causes the mounting operation to fail rarely occurs. The locations where errors occur are various, such as in the component supply unit, in the component mounting tool, and in the data used for the mounting operation. By performing appropriate maintenance according to an increase in the error rate and the location where the error occurs, it is possible to maintain good production efficiency of the component mounting machine. One technical example regarding the cause estimation of errors occurring in a component mounting machine is disclosed in Patent Document 1.

[0003] The mounting error cause estimation device disclosed in Patent Document 1 selects a first factor and a second factor from devices and data that can cause a mounting error, determines whether the error occurrence status obtained for each individual of the second factor is biased under the condition where the first factor is specified, determines whether the error occurrence status obtained for each individual of the first factor is biased under the condition where the second factor is specified, and estimates the error cause individual of the mounting error based on the two determination results. According to this, it is said that based on a large number of determination results, the error cause individual can be estimated with higher reliability than before.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] However, in Patent Document 1, when a parts supply unit (device) is suspected to be the faulty component, it is not possible to distinguish whether the fault lies in the parts supply unit itself or in the parts housing component it contains. When the fault locator cannot be accurately identified, it becomes difficult to perform proper maintenance. As a consequence, the increased error rate may not improve, or the burden on workers may be unnecessarily increased due to the performance of unnecessary maintenance.

[0006] Therefore, the problem to be solved in this specification is to provide a production management device that can estimate whether the component supply unit or the component housing member is the source of the error. [Means for solving the problem]

[0007] This specification discloses a production management device comprising: a calculation unit that calculates the error rate of a mounting operation after the mounting operation of mounting components supplied by a component supply unit, which is set to be replaceable as a component housing member, onto a substrate has been repeatedly performed, for each predetermined period that includes at least the time when the component housing member is replaced; and an estimation unit that estimates whether the component supply unit or the component housing member has the location of the error based on the error rate for each predetermined period.

[0008] Furthermore, this specification discloses the technical idea of ​​changing "the production control device described in any one of claims 1 to 3" to "the production control device described in any one of claims 1 to 5" in claim 6 of the original application; the technical idea of ​​changing "the production control device described in any one of claims 1 to 3" to "the production control device described in any one of claims 1 to 6" in claim 7 of the original application; the technical idea of ​​changing "the production control device described in any one of claims 1 to 3" to "the production control device described in any one of claims 1 to 7" in claim 8 of the original application; and the technical idea of ​​changing "the production control device described in any one of claims 1 to 3" to "the production control device described in any one of claims 1 to 9" in claim 10 of the original application. [Effects of the Invention]

[0009] In the production management device disclosed herein, the calculation unit calculates the error rate for each predetermined period divided into before and after the replacement time of the parts storage member. Based on how the error rate differs before and after the replacement time, the estimation unit can estimate whether the parts supply unit or the parts storage member has the source of the error. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic plan view showing the overall configuration of a parts mounting machine incorporating the production control device of the first embodiment. [Figure 2] This is a schematic side view illustrating the configuration of a tape feeder, which is a type of parts supply unit. [Figure 3] This is a diagram illustrating the operation flow of a production control device. [Figure 4] This is the first example diagram illustrating the temporal progression of the error rate, showing a case where the component supply unit (tape feeder) is the source of the problem. [Figure 5] This is a second example illustrating the temporal progression of the error rate, showing a case where the component housing (reel or carrier tape) is the source of the problem. [Figure 6]This is a diagram illustrating a table that explains the estimation operation of the estimation unit. [Figure 7] This figure schematically shows a production control device according to the second embodiment. [Figure 8] This is a diagram illustrating the operation flow of the production management device according to the second embodiment. [Figure 9] This is a diagram illustrating a third example of the temporal progression of the error rate, showing a case where the setting of the predetermined period differs from that of the first embodiment, and where the pause control unit is functioning. [Modes for carrying out the invention]

[0011] 1. Example configuration of component mounting machine 1 First, the overall configuration of the component mounting machine 1, into which the production management device 7 of the first embodiment is incorporated, will be explained with reference to Figure 1. The component mounting machine 1 repeatedly performs mounting operations to attach components to the substrate K. In Figure 1, the horizontal direction from left to right on the paper is the X-axis direction for transporting the substrate K, the horizontal direction from the bottom (front) to the top (rear) of the paper is the Y-axis direction, and the vertical direction is the Z-axis direction. The component mounting machine 1 is composed of a substrate transport device 2, a component supply device 3, a component transfer device 4, and a control device 5, etc., which are assembled on a base 10.

[0012] The substrate transport device 2 consists of a pair of guide rails 21, a pair of transport belts (not shown), and a clamping mechanism (not shown). The pair of guide rails 21 extend in the X-axis direction, traversing slightly towards the rear of the upper surface of the base 10, and are assembled to the base 10 parallel to each other. The pair of transport belts rotate along the guide rails 21 with two parallel sides of the substrate K placed on them, transporting the substrate K to a stopping position near the center of the base 10. The clamping mechanism pushes up the transported substrate K and clamps it between itself and the guide rails 21 to position it. After the mounting operation by the component transfer device 4 is completed, the clamping mechanism releases the substrate K, and the transport belts transport the substrate K out of the machine.

[0013] The parts supply device 3 consists of a pallet stand 31 and a plurality of tape feeders 6. The pallet stand 31 is a roughly rectangular member in plan view and has a plurality of slots that are parallel to each other and extend in the Y-axis direction while being aligned in the X-axis direction. A tape feeder 6 is detachably inserted and mounted in each of the plurality of slots. The tape feeder 6 is a form of parts supply unit that supplies parts using a replaceable parts storage member. The tape feeder 6 has a replaceable carrier tape CT that holds a plurality of parts and a reel RL on which the carrier tape CT is wound. The tape feeder 6 supplies parts by sending the carrier tape CT to a supply position 65 set at the rear upper part (details will be described later).

[0014] The component transfer device 4 consists of a pair of guide rails 40, a Y-axis moving body 41, an X-axis moving body 42, a mounting head 43, a nozzle tool 44, a suction nozzle 45, a substrate recognition camera 46, and a component recognition camera 47. The pair of guide rails 40 are positioned on both edges of the base 10, separated in the X-axis direction, and extend parallel to each other in the Y-axis direction. The Y-axis moving body 41 is formed from a member that is long in the X-axis direction and is mounted on the pair of guide rails 40. The Y-axis moving body 41 moves in the Y-axis direction driven by a Y-direction drive mechanism (not shown). The X-axis moving body 42 is mounted on the Y-axis moving body 41 and moves in the X-axis direction driven by an X-direction drive mechanism (not shown).

[0015] The mounting head 43 is provided on the front surface of the X-axis moving body 42 and is disposed above the substrate transfer device 2 and the component supply device 3. The mounting head 43 moves horizontally in two directions together with the X-axis moving body 42. A rotationally symmetric nozzle tool 44 is rotatably provided below the mounting head 43. The nozzle tool 44 is driven by an R-axis drive mechanism (not shown) and rotates about the vertical central axis. The nozzle tool 44 has a plurality (four in the example of FIG. 1) of suction nozzles 45 equidistant from the vertical central axis. The suction nozzles 45 are driven by an elevating drive mechanism (not shown) to move up and down and are driven by a Q-axis drive mechanism (not shown) to rotate about the vertical axis. Further, negative pressure air and positive pressure air are selectively supplied to the suction nozzles 45 from an air supply mechanism (not shown). Thereby, the suction nozzles 45 perform a mounting operation of sucking components from the component supply device 3 and mounting them on the substrate K. Note that the mounting head 43 may be provided with one suction nozzle 45 with the nozzle tool 44 omitted, or a plurality of suction nozzles 45 may be arranged in a line or in a grid pattern.

[0016] The substrate recognition camera 46 is provided downward on the X-axis moving body 42 alongside the mounting head 43. The substrate recognition camera 46 images the position reference marks attached to the substrate K from above. The acquired image data is subjected to image processing, and the stop position of the substrate K is accurately determined. The component recognition camera 47 is provided upward on the base 10 between the substrate transfer device 2 and the component supply device 3. The component recognition camera 47 images and recognizes the component held by the suction nozzle 45 from below while the mounting head 43 is moving from the component supply device 3 to the substrate K. Thereby, the correctness of the component type is determined, and the position and orientation of the component with respect to the suction nozzle 45 are detected and reflected in the mounting process. As the substrate recognition camera 46 and the component recognition camera 47, digital imaging devices having imaging elements such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) can be exemplified.

[0017] The control device 5 is assembled to the base 10, and its position is not limited. The control device 5 is composed of a computer device that has a CPU and operates with software. Note that the control device 5 may be configured such that a plurality of CPUs are distributed and communicatively connected inside the machine. The control device 5 has a schematic input unit that receives commands, selection operations, etc. from an operator, and a schematic display unit that conveys various information to the operator.

[0018] The control device 5 receives the mounting job data 51 from a schematic host management device and stores (holds) it in the attached memory 52. The mounting job data 51 is data used for the mounting operation and is created for each type of substrate product (substrate K). The mounting job data 51 includes shape data for each type of substrate K, shape data for each type of component, component mounting coordinate data, data regarding the tape feeder 6 and the suction nozzle 45 to be used, and detailed procedure data for the mounting operation, etc. The control device 5 controls the substrate transfer device 2, the component supply device 3, and the component transfer device 4 based on the mounting job data 51 to advance the mounting operation.

[0019] 2. Configuration of the tape feeder 6 Next, the configuration of the tape feeder 6 will be described in detail with reference to FIG. 2. The tape feeder 6 is composed of a main body 61, a tape feeding mechanism 66, a feeder control unit 69, etc. The main body 61 is formed mainly using side plates that are long in the front-rear direction. The main body 61 has a detachable rail 62, a reel holding shaft 63, a guide rail 64, and a schematic peeling mechanism.

[0020] The detachable rail 62 is provided on the bottom surface of the main body 61 and extends in the Y-axis direction. The detachable rail 62 is inserted into a slot in the pallet stand 31, thereby mounting the tape feeder 6. The reel holding shaft 63 is provided at a lower front position of the main body 61 and extends in the X-axis direction. The reel holding shaft 63 rotatably and replaceably holds the central hole of the reel RL around which the carrier tape CT is wound. A label LB indicating the individual information and part type information of the reel RL is affixed to the side of the reel RL. The operation of replacing a used reel RL with another reel RL when the carrier tape CT has run out can be performed with the tape feeder 6 installed or detached.

[0021] The carrier tape CT consists of a base tape and a cover tape. The base tape has cavities for housing components formed at a constant pitch along the length of the tape. The cover tape is bonded to the base tape by two adhesive strips extending along the length of the tape. The cover tape covers the cavities and prevents components from falling out. Multiple feed holes are provided along one side edge of the carrier tape CT at a constant pitch along the length of the tape.

[0022] The guide rail 64 starts at a position diagonally above and behind the reel holding shaft 63, extends diagonally upward and to the rear, then extends horizontally to the rear, ending at the upper rear end of the main body 61. The supply position 65 is near the end of the guide rail 64. The guide rail 64 guides the carrier tape CT pulled out from the reel RL to the supply position 65. The peeling mechanism (not shown) is provided in the middle of the guide rail 64. The peeling mechanism peels the cover tape from the base tape, opening the cavity and enabling the suction nozzle 45 to pick up the parts.

[0023] The tape feeding mechanism 66 feeds the carrier tape CT at a constant pitch and supplies multiple components sequentially at the supply position 65. The tape feeding mechanism 66 consists of a sprocket 67, a drive motor 68, and a gear mechanism (not shown). The sprocket 67 is positioned diagonally downward and forward of the supply position 65 and is rotatably supported by the main body 61. The upper part of the sprocket 67 protrudes upward through a groove formed in the guide rail 64. The teeth on the outer circumference of the sprocket 67 engage with the feed holes of the carrier tape CT.

[0024] The drive motor 68 rotates the sprocket 67 via a gear mechanism. The drive motor 68, for example, is a stepping motor and can intermittently drive the sprocket 67 in fixed increments. This allows the carrier tape CT to be advanced at a fixed pitch. The drive motor 68 can also rotate in reverse, allowing the carrier tape CT to be returned. Furthermore, the drive motor 68 can operate for longer periods than intermittently, enabling long feeds at the start of use and long retractions at the end of use of the carrier tape CT.

[0025] The feeder control unit 69 is located on the main body 61, and its position is not limited. The feeder control unit 69 is a computer device that operates using software. The feeder control unit 69 controls the drive motor 68. The feeder control unit 69 is connected to the connector 6A, the tape detection sensor 6B, and the operation panel 6C. The connector 6A is located on the rear surface of the main body 61. When the tape feeder 6 is attached to the pallet stand 31, the connector 6A automatically mates with the receiving connector (not shown) of the pallet stand 31. This supplies power to the tape feeder 6. In addition, the feeder control unit 69 is connected to the control device 5 and proceeds with control according to commands from the control device 5.

[0026] The tape detection sensor 6B is positioned on the inclined portion near the starting point of the guide rail 64. The tape detection sensor 6B detects the presence or absence of the carrier tape CT being fed and outputs a detection signal to the feeder control unit 69. The operation panel 6C is positioned at the front end of the top surface of the main unit 61. The operation panel 6C has a mode selector switch 6D, a feed switch 6E, and a display unit (not shown). The mode selector switch 6D is a manual switch that switches between multiple operating modes of the feeder control unit 69, such as operation mode and adjustment mode. The feed switch 6E is a manual switch for feeding or rewinding the carrier tape CT. The display unit is a part that displays the current operating mode, operating status, presence or absence of abnormalities, etc., and is composed of multiple indicator lamps, for example.

[0027] Furthermore, the tape feeder 6 may be of a type in which the carrier tape CT is fed from a reel RL held in a separate reel holding device, rather than holding the reel RL inside the main body 61. In addition, a parts supply unit other than the tape feeder 6, such as a tray feeder using a tray in which multiple parts are arranged in a two-dimensional grid, or a stick feeder using a cylindrical stick in which multiple parts are arranged in a single row, may be detachably attached to the pallet stand 31. In other words, the parts storage member may be a tray or a stick.

[0028] 3. Configuration of the production control device 7 in the first embodiment We will now move on to a description of the production management device 7 of the first embodiment. As shown in Figure 1, the production management device 7 is configured inside the control device 5, or in other words, it is configured using the software of the control device 5. Note that the production management device 7 may be configured using a computer device other than the control device 5. The production management device 7 includes a calculation unit 71, an estimation unit 72, and a guidance unit 73.

[0029] The calculation unit 71 calculates the error rate E of the mounting operation after the mounting operation of mounting components supplied by the tape feeder 6 onto the substrate K has been repeatedly performed in the component mounting machine 1. More specifically, the calculation unit 71 calculates the error rate E for each predetermined period, which is divided into periods that include at least the time when the tape feeder 6 is replaced. This predetermined period is set using the period over which a predetermined number of mounting operations Ns have elapsed. This predetermined period can be rephrased as the period required for mounting a number of components equal to the predetermined number Ns. The calculation unit 71 counts the number of errors Ne in which the mounting operation failed throughout the predetermined period, and calculates the error rate E by dividing this number of errors Ne by the predetermined number Ns.

[0030] Furthermore, the calculation unit 71 calculates the error rate E for fractional counts Nh that are equal to or greater than a predetermined threshold count Nmin when the predetermined number of mounting operations Ns is divided according to the replacement timing of the reel RL and carrier tape CT (if the calculation requirements are met). In this case, the calculation unit 71 calculates the error rate E by dividing the number of errors Ne by the fractional count Nh. Also, the calculation unit 71 does not calculate the error rate E for fractional counts Nh that are less than the threshold count Nmin (if the calculation requirements are not met). Alternatively, even if the calculation unit 71 calculates the error rate E for fractional counts Nh that are less than the threshold count Nmin, the estimation unit 72 determines that this error rate E is invalid and does not use it. The threshold count Nmin is set to be large enough that an accidental error in a single mounting operation does not excessively affect the error rate E (to the extent that the error rate E has statistical reliability). Specifically, the threshold count Nmin is set to be between 20-30% and less than 100% of the predetermined number Ns.

[0031] The estimation unit 72 estimates whether the tape feeder 6 or the component storage member (reel RL, carrier tape CT) has the location of the error based on the error rate E for each predetermined period. The estimation unit 72 does not perform estimation while the error rate E does not exceed a predetermined threshold EX, and performs estimation when the error rate E exceeds the threshold EX. In detail, the estimation unit 72 performs the following estimation operation when the first error rate E when the first reel RL and carrier tape CT are set in the tape feeder 6 exceeds the threshold EX.

[0032] In other words, the estimation unit 72 first determines whether the cause of the error rate E exceeding the threshold EX lies in the suction nozzle 45 or the tape feeder 6. The estimation unit 72 makes a determination by applying, for example, the technology disclosed by the applicant in Patent Document 1. Specifically, the estimation unit 72 uses the combination of the suction nozzle 45 and the tape feeder 6 in question when the error rate E exceeded the threshold EX as a reference, and refers to the error rate E when only one of them is changed. The error rate E referred to may be one that has already been calculated, or it may be one that is calculated after changing the combination in the future.

[0033] For example, if the error rate E is reduced to a threshold EX when the suction nozzle 45 is changed to another suction nozzle 45 and combined with the tape feeder 6, the estimation unit 72 can determine that the suction nozzle 45 is the source of the problem. On the other hand, if the error rate E does not improve even after changing the suction nozzle 45, the estimation unit 72 can determine that the tape feeder 6 is the source of the problem. When multiple suction nozzles 45 attached to the nozzle tool 44 pick up parts from the tape feeder 6, the estimation unit 72 can easily perform this determination.

[0034] Furthermore, if the error rate E when the suction nozzle 45 is combined with another tape feeder 6 is reduced to a threshold EX and improved, the estimation unit 72 can determine that the tape feeder 6 has a problematic component. On the other hand, if the error rate E does not improve even after changing the tape feeder 6, the estimation unit 72 can determine that the suction nozzle 45 has a problematic component. When the suction nozzle 45 picks up parts from multiple tape feeders 6, the estimation unit 72 can easily perform this determination.

[0035] Here, when it is determined that the tape feeder 6 has a problematic area, it is not distinguished whether the problematic area lies with the tape feeder 6 device itself or with the set reel RL or carrier tape CT. To distinguish between these, the estimation unit 72 obtains a second error rate E after the use of the first reel RL and carrier tape CT has ended when the error rate E exceeded the threshold EX, and after the second reel RL and carrier tape CT have been set. The estimation unit 72 then estimates that the tape feeder 6 has a problematic area when the second error rate E exceeds the threshold EX. The estimation unit 72 also estimates that the problematic area lies with the first reel RL or carrier tape CT when the second error rate E does not exceed the threshold EX.

[0036] In other words, the estimation unit 72 estimates that the tape feeder 6 itself has a problem if the error rate E does not improve even after replacing the reel RL and carrier tape CT. Conversely, the estimation unit 72 estimates that the problem lies with the reel RL or carrier tape CT before replacement if the error rate E improves after replacing the reel RL and carrier tape CT.

[0037] Possible causes of problems with the tape feeder 6 itself include wear and increased play in the sprocket 67 and gear mechanism of the tape feeding mechanism 66, decreased control accuracy of the drive motor 68, and deformation or intrusion of dust into the guide rail 64. It is expected that the intended function and performance can be restored by having an operator inspect the internal condition of the tape feeder 6, replace parts, and perform cleaning. In other words, it is preferable to perform maintenance on the tape feeder 6 at the appropriate time, and neglecting it is not recommended.

[0038] Therefore, when the guide unit 73 estimates that the tape feeder 6 has a faulty component, it uses the display unit to guide the operator to perform maintenance on that tape feeder 6. By performing maintenance according to the guidance, the function and performance of the tape feeder 6 are restored. As a result, the parts mounting machine 1 can repeat mounting operations with high operational accuracy and good production efficiency. In addition, some models of tape feeder 6 are recommended to undergo periodic maintenance after supplying a predetermined quantity of parts or after a predetermined operating time has elapsed. When the guide unit 73 estimates that the tape feeder 6 of this model has a faulty component, it guides the operator to perform emergency maintenance.

[0039] On the other hand, possible causes of reel RL failure include changes in the shape of the area housing the carrier tape CT, intrusion of foreign matter, and wear of the center hole. Possible causes of carrier tape CT failure include errors in tape thickness and width dimensions, variations in the shape of the adhesive area, dimensional errors or inconsistencies in the cavity and feed holes, and uneven pitch. These issues are difficult to address during use and are essentially resolved by replacing the reel RL and carrier tape CT.

[0040] Therefore, when the guide unit 73 estimates that the reel RL or carrier tape CT has a faulty area, it displays only the estimation result or does nothing. The reel RL and carrier tape CT in question are used until the end and then replaced with another reel RL and carrier tape CT. In many cases, the error rate E improves naturally after the replacement.

[0041] Furthermore, the estimation unit 72 does not use the error rate E calculated before the change after the type of substrate K is changed. This is because the installation job data 51 is changed along with the change in the type of substrate K, and the usage status of the tape feeder 6 also changes, so the error rate E before and after the change is not considered to have continuity. Also, if the tape feeder 6 is removed from the pallet stand 31 and its use is interrupted, and then its use is resumed by reinstallation, the estimation unit 72 does not use the error rate E calculated before the removal. This is because the usage status of the tape feeder 6 changes due to reinstallation, so the error rate E before and after reinstallation is not considered to have continuity. The functions of the calculation unit 71, estimation unit 72, and guidance unit 73 will be described further in the following operation description.

[0042] 4. Operation of Production Control Device 7 Next, the operation of the production control device 7 will be explained using a specific example, with reference to Figures 3 to 6. The operation flow shown in Figure 3 proceeds according to the control from the control device 5, which includes the production control device 7. In addition, the horizontal axis of the first example shown in Figure 4 and the second example shown in Figure 5 shows the total number of mounting operations (×10,000 times), and the vertical axis shows the error rate E (%). Furthermore, the thick dashed vertical line indicates the replacement timing of the reel RL and carrier tape CT, and the usage periods from the first carrier tape CT1 to the fifth carrier tape CT5 are shown separately.

[0043] As a prerequisite for the first and second cases, it has been determined that the cause of the error rate E exceeding the threshold EX is not in the suction nozzle 45. Furthermore, it is assumed that the number of components contained in each of the first carrier tapes CT1 to the fifth carrier tapes CT5 before use is 24,000. Additionally, the predetermined number of mounting operations Ns is set to 10,000, the predetermined threshold number Nmin is 50% of the predetermined number Ns, which is 5,000, and the threshold EX for the error rate E is set to 0.2%. Also, it is assumed that in the initial conditions when the production management device 7 starts operation, the first carrier tape CT1 is set in each of the multiple tape feeders 6 before use. The above prerequisites and initial conditions are examples and are, of course, changeable.

[0044] In step S1 of Figure 3, the control device 5 causes the suction nozzle 45 to perform the mounting operation. In the next step S2, the calculation unit 71 of the production management device 7 counts the number of operations Np and the number of errors Ne for each of the multiple tape feeders 6. For tape feeders 6 that have been supplied with parts, the number of operations Np increases, and if the mounting operation is completed successfully, the number of errors Ne does not change, but if the mounting operation is erroneous, the number of errors Ne increases. For tape feeders 6 that have not been supplied with parts, the number of operations Np and the number of errors Ne do not increase.

[0045] In the next step, S3, the calculation unit 71 determines whether a predetermined number of mounting operations Ns has elapsed for each of the multiple tape feeders 6, that is, whether the number of operations Np has reached the predetermined number Ns. Hereafter, to avoid complexity, the explanation will proceed using only one tape feeder 6 as an example. The operation loop formed by steps S1 to S3 is repeated until the number of operations Np reaches the predetermined number Ns (= 10,000). When the number of operations Np reaches the predetermined number Ns, the operation flow exits the operation loop and proceeds to step S4.

[0046] In step S4, the calculation unit 71 determines whether the number of operations Np (10,000) crosses the carrier tape CT replacement time and determines the branch destination of the operation flow. If the operation flow crosses the replacement time, it proceeds to step S5; if it does not, it proceeds to step S6. In step S5, the calculation unit 71 selects a fractional number Nh greater than or equal to the threshold number Nmin and proceeds the operation flow to step S6. In step S6, the calculation unit 71 calculates the error rate E by dividing the error count Ne by a predetermined number Ns, or by dividing the error count Ne by the fractional number Nh (selected in step S5). After calculating the error rate E, the calculation unit 71 resets the number of operations Np, the number of errors Ne, and the fractional number Nh to zero.

[0047] In the first example shown in Figure 4, when the total number of operations reaches 10,000, the number of operations Np becomes 10,000, and the carrier tape CT does not reach its replacement time. Therefore, the calculation unit 71 calculates the error rate E1 by dividing the number of errors Ne that occurred during the 1st to 10,000th mounting operations by a predetermined number Ns (= 10,000). Furthermore, when the total number of operations reaches 20,000, the calculation unit 71 calculates the error rate E2 by dividing the number of errors Ne that occurred during the 10,001st to 20,000th mounting operations by a predetermined number Ns.

[0048] Furthermore, when the total number of operations reaches 30,000, the number of operations Np becomes 10,000, and the timing of the change from the first carrier tape CT1 to the second carrier tape CT2 is crossed. The first fractional operation count Nh using the first carrier tape CT1 before the change is 4,000 (= 24,000 - 20,000), and the second fractional operation count Nh using the second carrier tape CT2 after the change is 6,000 (= 30,000 - 24,000). The first fractional operation count Nh (= 4,000) is less than the threshold number Nmin (= 5,000) and does not meet the calculation requirements, while the second fractional operation count Nh (= 6,000) is greater than or equal to the threshold number Nmin and meets the calculation requirements. Therefore, the calculation unit 71 calculates the error rate E3 by dividing the error count Ne by the second fractional count Nh (= 6,000) for the 24,001st to 30,000th mounting operation using the second carrier tape CT2.

[0049] The calculation unit 71 calculates error rates E4 to E10 using the same calculation method below. Error rates E4, E6, E7, and E9 are calculated for a predetermined period that does not span the carrier tape CT replacement period. Error rate E5 is calculated by dividing the error count Ne by the fractional count Nh (= 8,000) for the 40,001st to 48,000th mounting operations using the second carrier tape CT2. Error rate E8 is calculated by dividing the error count Ne by the fractional count Nh (= 8,000) for the 72,001st to 80,000th mounting operations using the fourth carrier tape CT4. Error rate E10 is calculated by dividing the error count Ne by the fractional count Nh (= 6,000) for the 90,001st to 96,000th mounting operations using the fourth carrier tape CT4. Furthermore, in the second example shown in Figure 5, the calculation unit 71 calculates the error rates E11 to E20 using the same calculation method as in the first example.

[0050] In the next step S7, the estimation unit 72 compares the error rate E calculated by the calculation unit 71 with the threshold EX to determine the branch destination of the operation flow. If the error rate E does not exceed the threshold EX, the estimation unit 72 returns the operation flow to step S1 and does not perform the estimation operation. If the error rate E exceeds the threshold EX, the estimation unit 72 proceeds the operation flow to step S8 and performs the estimation operation.

[0051] The details of the estimation operation of the estimation unit 72 in step S8 are shown in the table in Figure 6. In the table, the pre-replacement error rate EF represents the error rate E before replacing the carrier tape CT, and the post-replacement error rate ER represents the error rate E after replacing the carrier tape CT. The symbol L indicates that the error rate E does not exceed the threshold EX, and the symbol H indicates that the error rate E exceeds the threshold EX. If multiple error rates E are calculated for a single carrier tape CT, the symbol H is used if at least one of the error rates E exceeds the threshold EX.

[0052] As shown in Case 1) of Figure 6, if neither the pre-replacement error rate EF nor the post-replacement error rate ER exceeds the threshold EX, the estimation unit 72 does not estimate the location of the cause. As shown in Case 2), if the pre-replacement error rate EF does not exceed the threshold EX, and the post-replacement error rate ER increases and exceeds the threshold EX, the estimation unit 72 does not estimate the location of the cause. In this case, the estimation unit 72 estimates the location of the cause after the next carrier tape CT replacement and the calculation of the error rate E after replacement, which leads to a transition to Case 3) or Case 4).

[0053] As shown in Case 3), if the pre-replacement error rate EF exceeds the threshold EX, and the post-replacement error rate ER decreases and no longer exceeds the threshold EX, the estimation unit 72 estimates that the pre-replacement reel RL or carrier tape CT is the source of the problem. As shown in Case 4), if both the pre-replacement error rate EF and the post-replacement error rate ER exceed the threshold EX, the estimation unit 72 estimates that the tape feeder 6 is the source of the problem.

[0054] In the first case, the error rates E1 to E6 calculated in order do not exceed the threshold EX. Therefore, while the error rates E1 to E6 are being calculated, the operation flow in Figure 3 returns from step S7 to step S1. The next calculated error rate E7 is approximately 0.23%, which exceeds the threshold EX (= 0.2%), and the operation flow proceeds to step S8. At this point, the estimation unit 72 does not estimate the cause based on the pre-replacement error rate EF (error rates E3, E4, E5) and post-replacement error rate ER (error rate E7), which correspond to case 2) in Figure 6.

[0055] Furthermore, the error rate E8 calculated next is approximately 0.25%, which exceeds the threshold EX. Moreover, a carrier tape CT was replaced between the error rate E7 when using the third carrier tape CT3 and the error rate E8 when using the fourth carrier tape CT4. Therefore, the estimation unit 72 estimates that the tape feeder 6 has a faulty component based on the pre-replacement error rate EF (error rate E7) and post-replacement error rate ER (error rate E8), which correspond to case 4).

[0056] On the other hand, in the second case, the error rates E11 to E16 calculated in order progressed similarly to the first case and did not exceed the threshold EX. The next calculated error rate E17 was approximately 0.29%, which exceeded the threshold EX (= 0.2%). At this point, the estimation unit 72 does not estimate the cause based on the pre-replacement error rate EF (error rates E13, E14, E15) and post-replacement error rate ER (error rate E17), which correspond to case 2).

[0057] Furthermore, the error rate E18 calculated next is approximately zero and does not exceed the threshold EX. Moreover, a carrier tape CT was replaced between the error rate E17 when using the third carrier tape CT3 and the error rate E18 when using the fourth carrier tape CT4. Therefore, the estimation unit 72 estimates that the reel RL or the third carrier tape CT3 before replacement has a faulty component, based on the pre-replacement error rate EF (error rate E17) and post-replacement error rate ER (error rate E18) corresponding to case 3).

[0058] In the next step S9, the guide unit 73 determines whether or not it is estimated that the tape feeder 6 has a problematic area, and determines the branching point of the operation flow. If it is estimated, the operation flow proceeds to step S10; otherwise, it returns to step S1. In step S10, the guide unit 73 guides the operator to perform maintenance on the tape feeder 6. In the next step S11, the operator removes the tape feeder 6 in question according to the guidance and installs another tape feeder 6. After this, the operation flow returns to step S1, and the installation operation continues. The operator also performs maintenance on the removed tape feeder 6 to prepare it for next use.

[0059] In the first case, after the error rate E8 is calculated, the guide unit 73 is activated because it is estimated that the tape feeder 6 has a faulty component. Following the guidance, the worker replaces the tape feeder 6 with another tape feeder 6 after the fourth carrier tape CT4 has finished using it. The other tape feeder 6 supplies components using the set fifth carrier tape CT5. Therefore, even if the error rates E9 and E10 when using the fourth carrier tape CT4 exceed the threshold EX, the error rate EA when using the fifth carrier tape CT5 is improved to below the threshold EX. Alternatively, the worker may replace the tape feeder 6 while the fourth carrier tape CT4 is still in use. In any case, the guidance from the guide unit 73 allows the worker to perform maintenance on the tape feeder 6 at the appropriate time.

[0060] On the other hand, in the second case, since it is presumed that the problem lies with the reel RL or the third carrier tape CT3 before replacement, the guide unit 73 does not operate. Furthermore, the operator does not need to do anything special. Nevertheless, the error rates E18, E19, and E20 after replacement with the fourth carrier tape CT4 are maintained below the threshold EX. In this way, the guide unit 73 does not guide the operator to perform unnecessary maintenance on the tape feeder 6, so the burden on the operator does not increase unnecessarily.

[0061] In the production management device 7 of the first embodiment, the calculation unit 71 calculates the error rate E for each predetermined period (a predetermined number of times Ns) divided before and after the replacement time of the component storage member (reel RL and carrier tape CT). Therefore, the estimation unit 72 can estimate which of the tape feeder 6 and the component storage member has the location of the error based on how the error rate E (error rate EF before replacement, error rate ER after replacement) differs before and after the replacement time.

[0062] 5. Configuration of the production control device 7A in the second embodiment Next, the configuration of the production management device 7A in the second embodiment will be explained, mainly focusing on the differences from the first embodiment, with reference to Figure 7. As shown in Figure 7, the production management device 7A in the second embodiment has an additional discrimination unit 74 and a pause control unit 75, and the function of the calculation unit 71A is changed. Also, in the second embodiment, the hardware configuration of the component mounting machine 1 is the same as in the first embodiment.

[0063] In the first embodiment, the predetermined number of mounting operations Ns corresponding to a predetermined period was set independently of the number of components contained in the carrier tape CT before use. As a result, fractional counts Nh occurred unevenly, causing the denominator when calculating the error rate E to fluctuate and complicating the calculation process. In the second embodiment, the calculation unit 71A sets the denominator when calculating the error rate E to a constant number, thereby simplifying the calculation process. Specifically, the calculation unit 71A sets the predetermined number of mounting operations Ns corresponding to a predetermined period based on the number of components contained in the carrier tape CT before use. For example, the calculation unit 71A uses the number of components contained in the carrier tape CT before use as the predetermined number of operations Ns. Alternatively, the calculation unit 71A divides the number of components contained in the carrier tape CT before use into equal parts and uses those divisions as the predetermined number of operations Ns.

[0064] The discrimination unit 74 operates after the estimation unit 72 has estimated the part containing the cause. The discrimination unit 74 refers to the estimation result of the estimation unit 72 and determines which of the three parts—the parts supply unit (tape feeder 6), the parts housing member (reel RL and carrier tape CT), and the data (mounting job data 51)—contains the cause. Similar to the estimation unit 72, the discrimination unit 74 performs discrimination by applying the technology disclosed by the applicant in Patent Document 1. Specifically, the discrimination unit 74 selects the part estimated by the estimation unit 72 as the first factor, selects a part of the mounting job data 51 as the second factor, and applies the technology disclosed in Patent Document 1.

[0065] As a second factor, for example, shape data for each type of part can be selected from the mounting job data 51. If shape data with a large error compared to the actual shape of the part is the source of the error, the discrimination unit 74 can determine that the mounting job data 51 has a source of the error. Because the technology disclosed in Patent Document 1 has limitations in its application, there may be cases where the discrimination unit 74 cannot identify and determine a single part. In this case, the discrimination unit 74 may indicate multiple parts that may have a source of the error as a result of the discrimination. In fact, multiple parts may be involved in increasing the error rate E. As can be seen from the above explanation, parts that the estimation unit 72 estimates do not have a source of the error are not subject to discrimination by the discrimination unit 74 and are not determined to be parts that have a source of the error.

[0066] The pause control unit 75 compares the error rate E with a second threshold EY each time it is calculated. The pause control unit 75 pauses the installation operation if the error rate E exceeds the second threshold EY. The second threshold EY is set to be greater than the threshold EX to prevent excessive economic losses from discarding parts due to errors and excessive time losses from retrying the installation operation to recover from errors.

[0067] 6. Operation of the production control device 7A in the second embodiment Next, the operation of the production control device 7A in the second embodiment will be explained with reference to Figures 8 and 9. The operation flow shown in Figure 8 proceeds according to the control from the control device 5, which includes the production control device 7A. The third example shown in Figure 9 is presented using the same format as the first and second examples.

[0068] In step S21 of Figure 8, the calculation unit 71A of the production management device 7A sets a predetermined number of mounting operations Ns corresponding to a predetermined period. In the third example shown in Figure 9, the calculation unit 71A divides the number of parts contained in the carrier tape CT before use (= 24,000) into two equal parts to obtain the predetermined number of operations Ns (= 12,000). However, it is not limited to this, and the predetermined number of operations Ns may be 24,000, which corresponds to the number of parts, or it may be 8,000, which is three equal parts.

[0069] The next steps S22 to S25 correspond to steps S1 to S3 and S6 of the first embodiment, and the calculation unit 71A calculates the error rate E. However, the operations corresponding to steps S4 and S5 of the first embodiment are unnecessary, and the operation flow is simplified. If there are a few errors in the number of components contained in the carrier tape CT, the calculation unit 71A includes that number of errors in a predetermined number of Ns and calculates the error rate E.

[0070] In the third case, the error rate E21 is calculated when half of the first carrier tape CT1 is used, and the error rate E22 is calculated when the first carrier tape CT1 is completely used. Similarly, the error rates E23 and E24 are calculated when the second carrier tape CT2 is used, the error rates E25 and E26 are calculated when the third carrier tape CT3 is used, and the error rates E27 and E28 are calculated when the fourth carrier tape CT4 is used. Error rates E21 to E25 do not exceed the threshold EX, while error rates E26 to E28 exceed the threshold EX.

[0071] In the next step S26, the pause control unit 75 compares the error rates E21 to E28 with the second threshold EY each time they are calculated to determine the branch destination of the operation flow. Since the error rates E21 to E28 do not exceed the second threshold EY, the operation flow proceeds to step S28. In step S28, after the error rate E27 has been calculated, the estimation unit 72 estimates that the tape feeder 6 has a faulty location based on the pre-replacement error rate EF (error rate E26) and post-replacement error rate ER (error rate E27) corresponding to case 4).

[0072] In the next step S29, the discrimination unit 74 operates. The discrimination result of the discrimination unit 74 will be one of the following (A) to (C). (A) The tape feeder 6 has a faulty component. (B) The installed job data 51 contains the source of the problem. (C) The tape feeder 6 or the loading job data 51 has a faulty component.

[0073] In the next step, S30, the discrimination unit 74 displays the discrimination result using the display unit. If the discrimination result is either (A) or (C) above, the guidance unit 73 also operates to guide the user to perform maintenance on the tape feeder 6. After this, the operation flow returns to step S22.

[0074] In the third example, the error rate E29 when using the fifth carrier tape CT5 is calculated by repeating steps S22 to S25. In step S26, the pause control unit 75 proceeds to step S27 based on the fact that the error rate E29 exceeds the second threshold EY. In step S27, the pause control unit 75 pauses the mounting operation. Furthermore, the pause control unit 75 notifies the operator that the operation is paused using a display unit or another means of communication.

[0075] In the production management device 7A of the second embodiment, a predetermined number of Ns is set based on the number of parts contained in the carrier tape CT before use, so that the denominator when calculating the error rate E becomes a constant number, and the calculation process of the calculation unit 71A is simplified. In addition, the function of the discrimination unit 74 determines whether the mounting job data 51 has a cause. Furthermore, the function of the pause control unit 75 causes the mounting operation to be temporarily paused when the error rate E exceeds the second threshold EY, so that the economic loss of discarding parts due to errors and the time loss due to retrying the mounting operation do not become excessive.

[0076] 7. Applications and Variations of Embodiments Furthermore, the calculation unit 71 of the first embodiment can be replaced with the calculation unit 71A of the second embodiment. In the second embodiment, the calculation unit 71 may not be changed, and only one of the discrimination unit 74 and the pause control unit 75 may be added. Moreover, in the second embodiment, the pause control unit 75 may calculate the error rate E with a denominator smaller than a predetermined number of times Ns to determine whether or not a pause is necessary. This allows the timing of the pause to be brought forward, thereby reducing economic and time losses. In addition, the first and second embodiments can be applied and modified in various ways. [Explanation of symbols]

[0077] 1: Component mounting machine 2: Board transport device 3: Component supply device 4: Component transfer device 45: Suction nozzle 5: Control device 51: Mounting job data 6: Tape feeder 7, 7A: Production management device 71, 71A: Calculation unit 72: Estimation unit 73: Guidance unit 74: Discrimination unit 75: Pause control unit K: Board CT: Carrier tape CT1~CT5: 1st~5th carrier tape RL: Reel E, E1~E10, EA, E11~E20, E21~E29: Error rate EF: Error rate before replacement ER: Error rate after replacement EX: Threshold EY: Second threshold

Claims

1. A component mounting machine includes a calculation unit that calculates the error rate of the mounting operation after the mounting operation, in which components supplied by a component supply unit set to replace component housing members are repeatedly mounted onto a circuit board, for each predetermined period divided at least to include the time when the component housing members are replaced. An estimation unit that estimates which of the parts supply unit and the parts housing member has the location of the error based on the error rate for each predetermined period, A production control device equipped with the following features.

2. The production management apparatus according to claim 1, wherein the estimation unit does not perform estimation while the error rate does not exceed a predetermined threshold, and performs estimation when the error rate exceeds the threshold.

3. The production management apparatus according to claim 2, wherein the estimation unit estimates that the component supply unit has the cause location when the first error rate of the mounting operation when the first component storage member is set in the component supply unit exceeds the threshold, and the second error rate of the mounting operation after the second component storage member is set in place of the first component storage member exceeds the threshold, and estimates that the component storage member has the cause location when the second error rate does not exceed the threshold.

4. The production management device according to any one of claims 1 to 3, wherein the predetermined period is set based on a predetermined number of times the mounting operation is performed.

5. The production management device according to claim 4, wherein the calculation unit calculates the error rate for fractional numbers of mounting operations that are equal to or greater than a predetermined threshold number of mounting operations, when fractional numbers are generated due to the replacement timing of the component housing member, and does not calculate the error rate for fractional numbers that are less than the threshold number of mounting operations.

6. The production management device according to any one of claims 1 to 3, further comprising a guide unit for guiding maintenance of the parts supply unit when the parts supply unit is presumed to have the aforementioned fault location.

7. The production management apparatus according to any one of claims 1 to 3, wherein the estimation unit does not use the error rate calculated before the change after the type of substrate has been changed.

8. The aforementioned component mounting machine holds data used for the mounting operation, The production management device includes a determination unit that, by referring to the estimation result of the estimation unit, determines whether the parts supply unit, the parts storage member, or the data has the cause location. A production control apparatus according to any one of claims 1 to 3.

9. The production management device according to claim 2 or 3, further comprising a pause control unit that pauses the installation operation when the error rate exceeds a predetermined second threshold that is greater than the threshold.

10. The component housing member is a carrier tape that holds a plurality of the components, and a reel around which the carrier tape is wound. The aforementioned parts supply unit is a tape feeder in which the carrier tape is set in a replaceable manner. A production control apparatus according to any one of claims 1 to 3.

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