Printing apparatus and printing method

Abstract

The present invention provides a printing apparatus and printing method that can perform printing on a circuit board using an appropriate mask according to the pattern of the pads that will be printed on the solder paste. [Solution] The control unit of the printing apparatus performs setting, determination, and printing processes when printing solder paste onto a substrate through the mask opening of a mask to be placed at the mask position in accordance with the printing operation of the printing unit. In the setting process, the control unit sets the suitable mask opening information of a suitable mask to be used for printing into the substrate data, and in the determination process, it determines whether the placement mask opening information of the mask to be placed matches the suitable mask opening information. Then, according to the determination result of the determination process, the control unit performs printing processes to cause the printing unit to perform a printing operation based on the substrate data.

Description

Technical Field

[0001] The present invention relates to a printing apparatus and a printing method for printing solder paste on a substrate.

Background Art

[0002] As a printing apparatus for printing solder paste on a substrate such as a printed circuit board, a screen printing apparatus that prints solder paste through a mask opening of a mask disposed above the substrate is known. A technique related to this type of printing apparatus is disclosed in Patent Document 1. In the technique disclosed in Patent Document 1, a mask ID code provided on the lower surface of the mask is imaged by a camera, the imaged image is subjected to image processing to recognize the mask ID, and the unique information of the mask corresponding to the mask ID is read from a storage device, and printing processing is performed by correcting the printing position according to the unique information.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a printing apparatus, it is required to use an appropriate mask according to the pattern of pads that are the printing portions of solder paste on a substrate. In this regard, in the technique disclosed in Patent Document 1, since only the unique information corresponding to the mask ID is read from the storage device when performing printing processing, there are cases where printing processing is performed without using an appropriate mask according to the pattern of pads on the substrate. In this case, there is a risk that printing defects may occur because solder paste is not properly printed on the pads on the substrate.

[0005] The object of the present invention is to provide a printing apparatus and a printing method that can perform printing processing using an appropriate mask according to the pattern of the pads that will be printed on the substrate. [Means for solving the problem]

[0006] A printing apparatus according to one aspect of the present invention is an apparatus for printing solder paste onto a substrate having pads on its surface. The printing apparatus comprises a support unit for supporting the substrate; a printing unit that includes a mask having mask openings corresponding to the pads on the substrate, and performs a printing operation to print the solder paste onto the pads on the substrate supported by the support unit through the mask openings of the mask, which is positioned at a mask position above the support unit; an imaging unit capable of imaging the mask; and a control unit that controls the support unit, the printing unit, and the imaging unit. The control unit performs the following steps: setting process to set suitable mask opening information for the mask opening of the suitable mask, with respect to substrate data which is pre-set to include information for identifying the substrate to be planned for printing the solder paste and information for identifying the suitable mask that is suitable for use on the substrate to be planned; determination process to have the imaging unit capture an image of the mask to be placed, create placement mask opening information for the mask opening of the mask to be placed based on the image, and determine whether the placement mask opening information matches the suitable mask opening information; and printing process to have the printing unit perform the printing operation based on the substrate data according to the determination result of the determination process.

[0007] According to this printing apparatus, the control unit sets conformance mask opening information for a mask suitable for use on a target substrate where solder paste printing is planned, in the substrate data referenced during the printing process. When a mask is placed at the mask position above the support unit that supports the substrate, the control unit creates placement mask opening information for the mask of the target mask based on the image of the mask to be placed captured by the imaging unit, and determines whether this placement mask opening information matches the conformance mask opening information set in the substrate data. In this case, the control unit can determine whether the mask to be placed at the mask position is an appropriate mask according to the pattern of pads on the substrate, using information about the mask opening corresponding to the pads on the substrate as a determination index. Then, by performing the printing process according to the determination result, the control unit can perform the printing process using an appropriate mask according to the pattern of pads on the substrate.

[0008] In the above-described printing apparatus, the control unit may, in the setting process, cause the imaging unit to capture an image of the mask to be fitted, and set the fitted mask aperture information in the substrate data based on the image.

[0009] In this embodiment, the control unit can create conformance mask aperture information to be set in the substrate data for use in determining a match with the placement mask aperture information, based on the image of the mask to be conformed captured by the imaging unit.

[0010] In the above-described printing apparatus, the control unit may, in the setting process, acquire design data including aperture design information relating to the mask aperture of the mask to be fitted, and set the fitted mask aperture information in the substrate data based on the aperture design information.

[0011] In this embodiment, the control unit can create conformance mask aperture information to be set in the substrate data for use in determining a match with the placement mask aperture information, based on the aperture design information included in the design data of the mask to be conformed.

[0012] In the above-described printing apparatus, if the control unit obtains the determination result in the determination process that the arrangement mask aperture information matches the conforming mask aperture information, it may proceed to the printing process.

[0013] In this embodiment, in the determination by the control unit using information about mask openings corresponding to pads on the substrate as a determination index, if the placement mask opening information matches the compatible mask opening information, it is determined that the mask to be placed at the mask position is an appropriate mask according to the pattern of pads on the substrate. The control unit can perform printing processing according to such determination results, thereby performing printing processing using an appropriate mask according to the pattern of pads on the substrate.

[0014] In the above-described printing apparatus, if the control unit obtains the determination result in the determination process that the arrangement mask aperture information does not match the conforming mask aperture information, it may output determination error information and stop the transition to the printing process.

[0015] In this embodiment, in the determination by the control unit using information about mask openings corresponding to pads on the substrate as a determination index, if the placement mask opening information does not match the compatible mask opening information, it is assumed that the mask to be placed at the mask position is not an appropriate mask according to the pattern of pads on the substrate. In such cases, the control unit outputs determination error information and stops the transition to the printing process, thereby notifying the operator or others that the mask to be placed is not appropriate, and preventing printing defects that would occur due to solder paste not being properly printed on the pads on the substrate.

[0016] In the above-described printing apparatus, if the control unit obtains the determination result in the determination process that the placement mask opening information does not match the conforming mask opening information, it may update the substrate data by changing the conforming mask opening information set in the substrate data to the placement mask opening information, and in the printing process, cause the printing unit to perform the printing operation based on the updated substrate data.

[0017] In this embodiment, a mask may be used in which the specifications of the mask openings have been changed due to a mask version upgrade or the like. When such a mask is placed at the mask position, it is expected that a determination result will be obtained indicating that the placed mask opening information does not match the compatible mask opening information. In such a case, the control unit can update the board data by changing the compatible mask opening information set in the board data to the placed mask opening information. The control unit can then perform printing based on the updated board data.

[0018] In the above-described printing apparatus, the imaging unit may also be capable of imaging the substrate in addition to the mask. In this case, the control unit, in the setting process, causes the imaging unit to capture an image of the mask to be fitted, and sets the fitted mask aperture information in the substrate data based on the image, and also causes the imaging unit to capture an image of the substrate to be planned, and sets the planned substrate pad information for the pads of the substrate to be planned in the substrate data based on the image, and proceeds to the determination process if the fitted mask aperture information and the planned substrate pad information match, and outputs setting error information if they do not match.

[0019] In this embodiment, the control unit sets the substrate data with planned substrate pad information relating to the pads of the substrate to be planned, in addition to the conforming mask aperture information, based on the image captured by the imaging unit. If the conforming mask aperture information and the planned substrate pad information match, it means that the pads of the substrate and the mask apertures of the mask match in the planned substrate and the mask to be conformed, for which information is set in the substrate data. In such cases, the control unit moves from the setting process to the determination process. On the other hand, if the conforming mask aperture information and the planned substrate pad information do not match, it is possible that the mask for which information is set in the substrate data is not suitable for use on the planned substrate, and it is assumed that the settings of the substrate data need to be reviewed. In such cases, the control unit can notify the operator or others that the settings of the substrate data need to be reviewed by outputting setting error information.

[0020] In the above-described printing apparatus, the control unit may, in addition to determining whether the placement mask aperture information matches the conforming mask aperture information in the determination process, have the imaging unit capture an image of the substrate to be supported, create support substrate pad information relating to the pads of the substrate to be supported based on the image, and determine whether the support substrate pad information matches the planned substrate pad information.

[0021] In this embodiment, when a mask to be placed is placed at the mask position, the control unit can determine whether the mask to be placed is an appropriate mask according to the pad pattern on the substrate by determining whether the placement mask aperture information based on the image of the mask to be placed captured by the imaging unit matches the conforming mask aperture information. Furthermore, when a substrate to be supported is supported by the support unit, the control unit can determine whether the substrate to be supported matches the planned substrate on which solder paste printing is planned by determining whether the support substrate pad information based on the image of the substrate to be supported captured by the imaging unit matches the planned substrate pad information.

[0022] In the above-described printing apparatus, when the control unit obtains a determination result in the determination process that the arrangement mask aperture information matches the conformity mask aperture information and the support substrate pad information matches the planned substrate pad information, the control unit may shift to the printing process.

[0023] In this aspect, when the arrangement mask aperture information matches the conformity mask aperture information and the support substrate pad information matches the planned substrate pad information, it means that the substrate to be supported by the support unit matches the substrate to be planned, and a determination result is obtained that the mask to be arranged at the mask position is an appropriate mask according to the pattern of the pads on the substrate to be supported. The control unit can perform the printing process according to such a determination result, and can perform the printing process using an appropriate mask according to the pattern of the pads on the substrate.

[0024] In the above-described printing apparatus, when the control unit obtains a determination result in the determination process that the arrangement mask aperture information does not match the conformity mask aperture information or the support substrate pad information does not match the planned substrate pad information, the control unit may output determination error information and stop shifting to the printing process.

[0025] In this embodiment, if the placement mask opening information does not match the compatible mask opening information, or if the support substrate pad information does not match the planned substrate pad information, it is assumed that the mask to be placed at the mask position is not an appropriate mask according to the pattern of pads on the substrate, or that the substrate supported by the support unit does not match the planned substrate. In such cases, the control unit outputs judgment error information and stops the transition to the printing process, thereby notifying the operator or others that the mask to be placed is not appropriate or that the supported substrate does not match the planned substrate, and preventing printing defects that would occur due to solder paste not being properly printed on the pads on the substrate.

[0026] In the above-described printing apparatus, if the control unit obtains the determination result in the determination process that the placement mask opening information does not match the conforming mask opening information, it updates the substrate data by changing the conforming mask opening information set in the substrate data to the placement mask opening information. If the control unit obtains the determination result in the determination process that the support substrate pad information does not match the planned substrate pad information, it updates the substrate data by changing the planned substrate pad information set in the substrate data to the support substrate pad information. In the printing process, it may cause the printing unit to perform the printing operation based on the updated substrate data.

[0027] In this aspect, it is assumed that when a mask whose mask opening specifications have been changed due to a version update or the like is placed at the mask position, a determination result that the arranged mask opening information does not match the compatible mask opening information can be obtained. In such a case, the control unit can update the substrate data by changing the compatible mask opening information set in the substrate data to the arranged mask opening information. Further, when a substrate with a changed plan is supported by the support unit, it is assumed that a determination result that the supported substrate pad information does not match the planned substrate pad information can be obtained. In such a case, the control unit can update the substrate data by changing the planned substrate pad information set in the substrate data to the supported substrate pad information. Then, the control unit can perform a printing process based on the updated substrate data.

[0028] A printing method according to another aspect of the present invention is a printing method including a support unit that supports a substrate having pads on a surface, a printing unit including a mask that is disposed at a mask position above the support unit and has mask openings corresponding to the pads of the substrate, and an imaging unit that can image the mask. In the printing method, solder paste is printed on the pads on the substrate to be supported by the support unit through the mask openings of the mask to be arranged at the mask position according to the printing operation of the printing unit. This printing method includes a setting step of setting compatible mask opening information regarding the mask openings of the mask for the target of compatibility for information for specifying the substrate for the target of the plan for which the printing of the solder paste is planned and information for specifying the mask for the target of compatibility that is suitable for use with the substrate for the target of the plan in the preset substrate data, a determination step of causing the imaging unit to image an image of the mask to be arranged, creating arranged mask opening information regarding the mask openings of the mask to be arranged based on the image, and determining whether the arranged mask opening information matches the compatible mask opening information, and a printing step of causing the printing unit to perform the printing operation based on the substrate data according to the determination result of the determination step.

[0029] According to this printing method, in the setup step, suitable mask opening information for a suitable mask that is suitable for use on a target substrate where solder paste printing is planned is set in the substrate data referenced in the printing step. Then, when a mask is placed at the mask position above the support unit that supports the substrate, in the determination step, placement mask opening information for the mask of the target mask is created based on the image of the mask of the target mask captured by the imaging unit, and it is determined whether the placement mask opening information matches the suitable mask opening information set in the substrate data. In this case, in the determination step, information regarding the mask opening corresponding to the pads on the substrate can be used as a determination index to determine whether the target mask placed at the mask position is an appropriate mask according to the pattern of the pads on the substrate. Then, in the printing step, by causing the printing unit to perform a printing operation according to the determination result of the determination step, it becomes possible to cause the printing unit to perform a printing operation using an appropriate mask according to the pattern of the pads on the substrate. [Effects of the Invention]

[0030] As described above, the present invention provides a printing apparatus and a printing method that can perform printing processing using an appropriate mask according to the pattern of the pads that will be printed on the substrate. [Brief explanation of the drawing]

[0031] [Figure 1] This figure schematically shows the configuration of a component mounting system to which a printing apparatus according to an embodiment of the present invention is applied. [Figure 2] This is a block diagram of a printing device. [Figure 3] This is a side view of a printing device. [Figure 4] This is a front view of the printing device. [Figure 5] This diagram illustrates the setting process performed by the control unit of a printing device. [Figure 6]This diagram illustrates the judgment and printing processes performed by the control unit. [Figure 7] This is a flowchart illustrating the configuration process performed by the control unit. [Figure 8] This is a flowchart illustrating the decision-making process performed by the control unit. [Figure 9] This diagram illustrates a modified example of the setting process performed by the control unit. [Figure 10] This diagram illustrates modified examples of the judgment and printing processes performed by the control unit. [Figure 11] This is a flowchart illustrating a modified version of the setting process performed by the control unit. [Figure 12] This is a flowchart illustrating a modified version of the judgment process performed by the control unit. [Modes for carrying out the invention]

[0032] The printing apparatus and printing method according to the embodiments of the present invention will be described below with reference to the drawings. In the following description, directional relationships will be described using the XYZ Cartesian coordinate system. That is, directions that are orthogonal to each other on the horizontal plane will be referred to as the X-axis direction and the Y-axis direction, and the vertical direction that is orthogonal to the X-axis direction and the Y-axis direction will be referred to as the Z-axis direction. The printing apparatus according to this embodiment is applied to a component mounting system for mounting components on a substrate such as a printed circuit board, and is an apparatus for printing solder paste such as solder paste onto the substrate. The printing method is a method for printing solder paste onto a substrate using the printing apparatus.

[0033] [Overall configuration of the component mounting system] Figure 1 is a schematic diagram showing the configuration of a component mounting system PMS to which a printing apparatus 1 according to an embodiment of the present invention is applied. The component mounting system PMS includes a production line PL. The production line PL is a line in which a printing apparatus 1, a printing inspection apparatus PIM, a mounting apparatus MM, a reflow apparatus RM, and a substrate inspection apparatus BIM are arranged as multiple work devices for producing mounted substrates PB with components mounted on them. In the production line PL, the printing apparatus 1, the printing inspection apparatus PIM, the mounting apparatus MM, the reflow apparatus RM, and the substrate inspection apparatus BIM are arranged in tandem from the upstream side to the downstream side in the substrate transport direction on a substrate transport path TP that transports substrates PB. A loader LD for transporting substrates PB to the printing apparatus 1 is located at the upstream end of the production line PL, and an unloader ULD for removing the produced substrates PB from the substrate inspection apparatus BIM is located at the downstream end.

[0034] Printing apparatus 1 performs the task of printing solder paste, such as solder paste, onto substrate PB using a screen printing method with a mask 4. Here, the relationship between substrate PB and mask 4 will be explained. Substrate PB has a pattern of multiple pads PB1 on its surface, which will be the printing areas for the solder paste. Mask 4 has multiple mask openings 41 corresponding to each pad PB1 on substrate PB. The shape, position, and size of each mask opening 41 on mask 4 must match the shape, position, and size of each pad PB1 on substrate PB that corresponds to each mask opening 41. As will be described in detail later, in printing apparatus 1, solder paste is printed onto the pads PB1 on substrate PB through the mask openings 41 of mask 4 which are positioned above substrate PB.

[0035] The Printing Inspection Device (PIM) inspects whether the position, amount, and height of the solder paste printed on the substrate (PB) are correct. The Printing Inspection Device (PIM) includes a Printing Inspection Unit (PIMU) that inspects the printing state of the solder paste on each pad (PB1) on the substrate (PB). The Printing Inspection Unit (PIMU) captures an image of the substrate (PB) with the solder paste printed on each pad (PB1), and based on this image, it moves above the substrate (PB) while recognizing the FID (fiducial) marks and the size of the substrate (PB), and inspects the printing state of the solder paste on each pad (PB1) on the substrate (PB).

[0036] The mounting device MM produces mounted circuit boards by mounting components onto a circuit board PB with solder paste printed on it. The mounting device MM is equipped with a mounting unit MMU that performs the work required to produce mounted circuit boards. The mounting unit MMU captures images of the circuit board PB and components, acquires captured images, and moves above the circuit board PB while recognizing FID marks, the size of the circuit board PB, and the shape of the components based on these captured images, and mounts the components onto the circuit board PB.

[0037] The reflow machine RM heats the mounted circuit board produced by the mounting machine MM to melt the solder and fix the components to the circuit board PB.

[0038] The PCB inspection system (BIM) is a device for inspecting mounted circuit boards and is positioned at the downstream end of the production line (PL) in the direction of board transport. The BIM inspects for misalignment of components, lead misalignment, component lifting, mounting omissions, soldering defects, and foreign matter inclusion on the mounted circuit board. The BIM includes a PCB inspection unit (BIMU) that performs the work of inspecting the mounted circuit board. The BIMU captures an image of the mounted circuit board, acquires the image, and moves above the mounted circuit board while recognizing the FID mark, the size of the mounted circuit board, and the position of components on the mounted circuit board based on the image, to inspect for misalignment of components, etc. In addition to being positioned at the downstream end of the production line (PL) in the direction of board transport, the BIM may also be positioned between the mounting unit (MM) and the reflow unit (RM). In this case, the BIM inspects the mounted circuit board before the reflow process by the reflow unit (RM).

[0039] [Detailed configuration of the printing device] Printing apparatus 1 prints solder paste onto each pad PB1 on the substrate PB. Printing apparatus 1 will be described in detail with reference to Figures 2, 3, and 4. Printing apparatus 1 is a so-called screen printing apparatus and is equipped with a base 1A. On this base 1A, an input conveyor 2a, an output conveyor 2b, and a printing stage 3 located between these two conveyors 2a and 2b are arranged in the Y-axis direction. In printing apparatus 1, the substrate PB is transported to the printing stage 3 by the input conveyor 2a, where it undergoes a printing process to print solder paste, and then is transported out by the output conveyor 2b.

[0040] A four-axis unit AU is installed on the printing stage 3. The four-axis unit AU supports the substrate PB and loads the substrate PB onto the mask 4 (described later) from below. It horizontally supports the substrate PB that has been brought in by the transport conveyor 2a and supports it so that it can be displaced in the X-axis direction, Y-axis direction, Z-axis direction, and R (around the Z-axis).

[0041] Specifically, the 4-axis unit AU is hierarchically comprised of, from bottom to top, a fixed table 11 fixed on a base 1A, an X-axis table 12 movable in the X-axis direction relative to the fixed table 11, a Y-axis table 13 movable in the Y-axis direction relative to the X-axis table 12, an R-axis table 14 rotatable around the Z-axis relative to the Y-axis table 13, and a lifting table 15 that can be raised and lowered in the Z-axis direction relative to the R-axis table 14. A support unit SU is mounted on the lifting table 15, and the substrate PB is supported by this support unit SU, so that the substrate PB moves in the X-axis, Y-axis, Z-axis, and R-axis directions by driving each of the tables 12, 13, 14, and 15.

[0042] The support unit SU includes a conveyor 19 that supports the substrate PB so that it can be transported in the Y-axis direction, a support mechanism 17 for supporting the substrate PB, and a clamping mechanism 18 for clamping the substrate PB. Specifically, the support unit SU receives the substrate PB from the input conveyor 2a onto the conveyor 19, lifts the substrate PB from the conveyor 19 by supporting it from below with the support mechanism 17, and clamps the substrate PB from both sides in the X-axis direction with the clamping mechanism 18. In this way, the support unit SU positions and fixes the substrate PB in a predetermined position on the lifting table 15.

[0043] The printing apparatus 1 includes a printing unit PU positioned above the printing stage 3, i.e., above the support unit SU. The printing unit PU is a unit that performs the printing operation of printing solder paste onto each pad PB1 on the substrate PB, and includes a mask 4, a solder supply unit 5, and a squeegee unit 6.

[0044] The mask 4 is positioned horizontally at a predetermined mask position MP above the support unit SU. The mask 4 has mask openings 41 corresponding to each pad PB1 on the substrate PB, and is interchangeably positioned at the mask position MP above the substrate PB supported by the support unit SU. The mask 4 is, for example, a stainless steel plate-shaped member, stretched over a predetermined frame, and interchangeably incorporated into the printing apparatus 1 via the frame. The mask 4 is replaced by a mask replacement unit 7. A movable cleaning device 9 is positioned directly below the mask 4, and as the printing process progresses, this cleaning device 9 slides along the underside of the mask 4 at regular intervals to remove solder paste adhering to the underside of the mask 4 and the mask openings 41. During the printing process, this cleaning device 9 is positioned in a predetermined retracted position outside the mask 4.

[0045] An imaging unit CIU is positioned below the mask 4 and above the support unit SU. The imaging unit CIU is supported so as to be movable in the X-axis direction and is driven by a servo motor or the like. The imaging unit CIU can image the mask 4, which is positioned at mask position MP, from below, and can also image the substrate PB, which is supported by the support unit SU, from above. In the printing apparatus 1, after the relative position of the substrate PB with respect to the mask 4 is recognized based on the images of the mask 4 and the substrate PB captured by the imaging unit CIU, the relative position of the substrate PB with respect to the mask 4 is precisely positioned by driving the X-axis table 12, Y-axis table 13, and R-axis table 14 in the 4-axis unit AU of the printing stage 3. Then, in the printing apparatus 1, with the relative position of the substrate PB with respect to the mask 4 precisely positioned, the substrate PB is raised by driving the lifting table 15 in the 4-axis unit AU, and the substrate PB supported by the support unit SU comes into contact with the lower surface of the mask 4.

[0046] The solder supply unit 5 is positioned above the mask 4. The solder supply unit 5 supplies solder paste onto the mask 4. The solder supply unit 5 is mounted on a unit support member 21 that supports the squeegee unit 6. The solder supply unit 5 is driven by drive mechanisms 22, 23, and 24 supported by the unit support member 21.

[0047] The squeegee unit 6 is positioned above the mask 4. The squeegee unit 6 is a unit for printing solder paste onto each pad PB1 on the substrate PB through each mask opening 41 of the mask 4 by moving the solder paste along the mask 4. The squeegee unit 6 is supported so as to be movable in the X-axis direction and is driven by a servo motor or the like. Specifically, above the mask 4, there is a pair of fixed rails 20 extending in the X-axis direction, a unit support member 21 extending in the Y-axis direction and supported so as to be movable on each fixed rail 20, and a drive mechanism such as a screw feed mechanism that drives the unit support member 21 using a servo motor 20A as the drive source. The squeegee unit 6 is supported by the unit support member 21. The squeegee unit 6 is movable in the X-axis direction together with the unit support member 21 by the drive of the servo motor 20A.

[0048] The squeegee unit 6 is equipped with a squeegee 6a. The squeegee 6a is connected to a drive mechanism, such as a screw feed mechanism, which drives the squeegee 6a using a servo motor or the like as the drive source. As a result, the squeegee 6a can move up and down in the Z-axis direction relative to the squeegee unit 6. The squeegee 6a spreads solder paste on the mask 4 and moves along the mask 4, and is made of, for example, a long, narrow rigid urethane in the Y-axis direction, or a metal plate member such as stainless steel. The squeegee 6a is pressed against the mask 4 by descending in the Z-axis direction relative to the squeegee unit 6, and in this state, the squeegee unit 6 moves in the X-axis direction together with the unit support member 21, causing the squeegee 6a to slide along the mask 4.

[0049] The printing unit PU performs a printing operation in which solder paste is printed onto each pad PB1 on the substrate PB supported by the support unit SU through each mask opening 41 of the mask 4, in response to the sliding of the squeegee 6a along the mask 4 to be placed, which is positioned at the mask position MP.

[0050] As shown in Figure 2, the printing apparatus 1 further comprises a control unit CU, a storage unit MU, a display unit DU, and an operation unit OU. The control unit CU is composed of a processor that operates by loading a predetermined program. The control unit CU performs processing to control the support unit SU, the printing unit PU, and the imaging unit CIU, as well as processing to control the display unit DU and the operation unit OU.

[0051] The memory unit MU stores various information and data. The display unit DU is a display that shows various information and data. The operation unit OU consists of a keyboard, mouse, or a touch panel provided on the display unit DU. The operation unit OU accepts input operations of various commands from the operator.

[0052] <Regarding the processing performed by the control unit> Each process performed by the control unit CU will be explained with reference to the flowcharts in Figures 5 and 6, and Figures 7 and 8. The control unit CU performs the setting process, the determination process, and the printing process of the printing method using the printing device 1 by performing setting processing, determination processing, and printing processing. The control unit CU performs the printing process in conjunction with the production of mounted boards on the production line PL in the component mounting system PMS, and performs the setting process and determination process before the printing process.

[0053] (Setup process) Referring to Figures 5 and 7, in the setup process, the control unit CU acquires the board data BD (step a1). The board data BD is data that the control unit CU refers to when performing the printing process, and consists of pre-set data for board identification information BJ, mask identification information MJ, solder identification information HJ, and squeegee identification information SJ.

[0054] The substrate identification information BJ is information for identifying the substrate PB on which solder paste printing is planned. The substrate identification information BJ includes information such as the substrate name, size, and thickness to identify the substrate PB on which the plan is planned. The mask identification information MJ is information for identifying the mask 4 that is suitable for use on the substrate PB on which the plan is planned. The mask identification information MJ includes information such as the mask name and size to identify the mask 4 that is suitable for use on the mask PB on which the plan is planned.

[0055] Solder identification information HJ is information for identifying a suitable solder paste for use on the planned substrate PB, and includes information such as the solder name. Squeegee identification information SJ is information for identifying a suitable squeegee 6a for use on the planned substrate PB. Squeegee identification information SJ includes information for identifying the suitable squeegee 6a, such as the squeegee name, pressing force, contact angle, and travel speed. The pressing force is the pressure applied when the squeegee 6a is pressed against the mask 4. The contact angle is the angle between the squeegee 6a and the mask 4 when the squeegee 6a is pressed against the mask 4. The travel speed is the speed at which the squeegee 6a moves on the mask 4.

[0056] When the substrate data BD is acquired, the control unit CU creates conformance mask aperture information MAJ1 for each mask aperture 41 of the mask 4 to be conformed (step a2). In this case, the control unit CU can create conformance mask aperture information MAJ1 for each mask aperture 41 of the mask 4 to be conformed by having the imaging unit CIU capture an image of the mask 4 to be conformed and performing analysis processing such as image processing on the image.

[0057] The control unit CU may also acquire mask design data MDD for the mask 4 to be adapted and create adapted mask aperture information MAJ1 based on the aperture design information ADJ contained in the mask design data MDD. The mask design data MDD is design data in Gerber format used in the design of the mask 4 to be adapted, and stores aperture design information ADJ for each mask aperture 41 of the mask 4 to be adapted. The control unit CU can create adapted mask aperture information MAJ1 for each mask aperture 41 of the mask 4 to be adapted by performing analysis processing on the aperture design information ADJ contained in the mask design data MDD.

[0058] The conformance mask aperture information MAJ1 created by the control unit CU includes information about each mask aperture 41 of the mask 4 to be conformed, such as the shape, position, and size of each mask aperture 41.

[0059] Once conformance mask opening information MAJ1 is created for each mask opening 41 of the mask 4 to be conformed, the control unit CU accepts a selection operation by the operator via the operation unit OU to determine whether a determination is necessary (step a3). The selection operation to determine whether a determination is necessary is an operation to select whether a determination is necessary in the determination process that the control unit CU performs after the setting process, for each conformance mask opening information MAJ1 for each mask opening 41 of the mask 4 to be conformed. That is, the operator should select "Determination Required" for the conformance mask opening information MAJ1 for each mask opening 41 of the mask 4 to be conformed that needs to be processed by the determination process by the control unit CU, and select "Determination Not Required" for the conformance mask opening information MAJ1 for each mask opening 41 that does not need to be processed by the determination process. In response to the selection operation by the operator via the operation unit OU, the control unit CU adds determination requirement information to the conformance mask opening information MAJ1 for each mask opening 41 of the mask 4 to be conformed.

[0060] When information indicating whether a determination is necessary is added to the conforming mask aperture information MAJ1, the control unit CU sets the conforming mask aperture information MAJ1 to the substrate data BD, which has substrate identification information BJ, mask identification information MJ, solder identification information HJ, and squeegee identification information SJ pre-configured (step a4). Then, the control unit CU stores the substrate data BD with the conforming mask aperture information MAJ1 set in the storage unit MU (step a5), and ends the setting process. After ending the setting process, the control unit CU moves on to the determination process.

[0061] (Judgment processing and printing processing) The control unit CU performs a determination process after the setting process is complete if the mask 4 is placed at the mask position MP above the support unit SU that supports the substrate PB. Referring to Figures 6 and 8, in the determination process, the control unit CU reads the substrate data BD, in which the conforming mask aperture information MAJ1 is set, from the storage unit MU (step b1). When the control unit CU recognizes that the mask 4 has been placed at the mask position MP (step b2), it causes the imaging unit CIU to capture an image of the mask 4 to be placed at the mask position MP (step b3). The control unit CU performs image processing and other analysis processing on the image captured by the imaging unit CIU to create placement mask aperture information MAJ2 for each mask aperture 41 of the mask 4 to be placed (step b4). In this case, the control unit CU may create placement mask aperture information MAJ2 in accordance with the mask aperture 41 to which the information "determination required" has been added as information on whether determination is required in the conforming mask aperture information MAJ1 set in the substrate data BD.

[0062] The placement mask opening information MAJ2 created by the control unit CU includes information about each mask opening 41 of the mask 4 to be placed, such as the shape, position, and size of each mask opening 41.

[0063] The control unit CU then determines whether the placement mask opening information MAJ2 for each mask opening 41 of the mask 4 to be placed matches the compatible mask opening information MAJ1 set in the substrate data BD (step b5). In this case, the control unit CU can determine whether the mask 4 to be placed, placed at mask position MP, is an appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB, using the information of each mask opening 41 corresponding to each pad PB1 on the substrate PB as a determination index. Then, the control unit CU performs a printing process that causes the printing unit PU to perform a printing operation based on the substrate data BD according to the determination result in the determination process. This makes it possible for the control unit CU to perform the printing process using an appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB.

[0064] If the control unit CU determines that the placement mask opening information MAJ2 matches the compatible mask opening information MAJ1 (YES in step b5), it performs printing processing by causing the printing unit PU to perform printing operations based on the substrate data BD. In the determination by the control unit CU, which uses information about each mask opening 41 corresponding to each pad PB1 on the substrate PB as a determination index, if the placement mask opening information MAJ2 matches the compatible mask opening information MAJ1, it is determined that the mask 4 to be placed at mask position MP is an appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB. By performing printing processing according to such determination results, the control unit CU can perform printing processing using an appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB.

[0065] If the determination result is obtained that the placement mask aperture information MAJ2 does not match the compatible mask aperture information MAJ1 (NO in step b5), it is determined whether a change operation to modify the compatible mask aperture information MAJ1 set in the board data BD has been received via the operation unit OU (step b6). In some cases, a mask 4 whose specifications for the mask aperture 41 have been changed due to a version upgrade of the mask 4 may be used. When such a mask 4 is placed at mask position MP, it is expected that the determination result will be obtained that the placement mask aperture information MAJ2 does not match the compatible mask aperture information MAJ1. In such a situation, if a change operation is received via the operation unit OU (YES in step b6), the control unit CU updates the board data BD by changing the compatible mask aperture information MAJ1 set in the board data BD to the placement mask aperture information MAJ2 (step b7), and stores the updated board data BD in the storage unit MU (step b8). Then, the control unit CU can perform printing processing to cause the printing unit PU to perform printing operations based on the updated board data BD stored in the storage unit MU.

[0066] If the placement mask opening information MAJ2 does not match the conforming mask opening information MAJ1, and no change operation has been accepted via the operation unit OU (NO in step b6), the control unit CU outputs judgment error information JE (step b9) and stops the transition to the printing process (step b10). The control unit CU may display the outputted judgment error information JE on, for example, the display unit DU. In the judgment by the control unit CU, which uses information about each mask opening 41 corresponding to each pad PB1 on the substrate PB as a judgment index, if the placement mask opening information MAJ2 does not match the conforming mask opening information MAJ1, it is assumed that the mask 4 to be placed, placed at mask position MP, is not the appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB. In such a case, by the control unit CU outputting judgment error information JE and stopping the transition to the printing process, it is possible to inform the operator that the mask 4 to be placed is not appropriate according to the output of judgment error information JE, and to prevent printing defects from occurring due to solder paste not being properly printed on each pad PB1 on the substrate PB.

[0067] <Examples of variations in the processing performed by the control unit> Modified examples of each process performed by the control unit CU will be explained with reference to the flowcharts in Figures 9 and 10, and Figures 11 and 12.

[0068] (Variation of the setup process) Referring to Figures 9 and 11, in the setup process, the control unit CU acquires board data BD in which board identification information BJ, mask identification information MJ, solder identification information HJ, and squeegee identification information SJ are pre-set (step a1).

[0069] Upon acquiring the substrate data BD, the control unit CU creates conformance mask aperture information MAJ1 for each mask aperture 41 of the mask 4 to be conformed, and also creates planned substrate pad information BPJ1 for each pad PB1 of the substrate PB to be planned (step a2). In this case, the control unit CU can create conformance mask aperture information MAJ1 for each mask aperture 41 of the mask 4 by having the imaging unit CIU capture an image of the mask 4 to be conformed and performing image processing or other analysis on the image. In addition, the control unit CU can create planned substrate pad information BPJ1 for each pad PB1 of the substrate PB to be planned by having the imaging unit CIU capture an image of the substrate PB on which solder paste printing is planned and performing image processing or other analysis on the image.

[0070] The conforming mask opening information MAJ1 created by the control unit CU includes information about each mask opening 41 of the mask 4 to be conformed, such as the shape, position, and size of each mask opening 41. Similarly, the planned substrate pad information BPJ1 created by the control unit CU includes information about each pad PB1 of the substrate PB to be planned, such as the shape, position, and size of each pad PB1.

[0071] Once the conforming mask opening information MAJ1 and the planned substrate pad information BPJ1 are created, the control unit CU accepts the operator's selection operation for whether or not a judgment is required via the operation unit OU (step a3). The selection operation for whether or not a judgment is required is an operation to select whether or not a judgment is required in the judgment process for each conforming mask opening information MAJ1 related to each mask opening 41 of the mask 4 to be conformed, and an operation to select whether or not a judgment is required in the judgment process for each planned substrate pad information BPJ1 related to each pad PB1 of the substrate PB to be planned. In other words, the operator should select "Judgment Required" for the conforming mask opening information MAJ1 related to each mask opening 41 of the mask 4 to be conformed, for mask openings 41 that need to be processed by the judgment process by the control unit CU, and select "Judgment Not Required" for the conforming mask opening information MAJ1 related to mask openings 41 that do not need to be processed by the judgment process. Furthermore, the operator can select "Judgment Required" for the planned substrate pad information BPJ1 for each pad PB1 of the substrate PB to be planned, for pads PB1 that need to be processed by the control unit CU, and select "Judgment Not Required" for pads PB1 that do not need to be processed by the control unit CU. The control unit CU adds judgment requirement information to the conforming mask opening information MAJ1 and the planned substrate pad information BPJ1 in response to the operator's selection operation of judgment requirement or not via the operation unit OU.

[0072] When information indicating whether a determination is necessary is added to the conforming mask opening information MAJ1 and the planned substrate pad information BPJ1, the control unit CU sets the conforming mask opening information MAJ1 and the planned substrate pad information BPJ1 for the substrate data BD, which has substrate identification information BJ, mask identification information MJ, solder identification information HJ, and squeegee identification information SJ set in advance (step a4). Then, the control unit CU stores the substrate data BD with the conforming mask opening information MAJ1 and the planned substrate pad information BPJ1 set in the storage unit MU (step a5). In this case, if the conforming mask opening information MAJ1 and the planned substrate pad information BPJ1 match, the control unit CU proceeds to the determination process, and if they do not match, it outputs setting error information SE. The control unit CU may also display the outputted setting error information SE on the display unit DU.

[0073] If the compatible mask opening information MAJ1 and the planned substrate pad information BPJ1 match, then the pads PB1 of the planned substrate PB and the mask openings 41 of the mask 4 match in the substrate data BD where information is set for the planned substrate PB and the compatible mask 4. In this case, the control unit CU moves from the setting process to the determination process. On the other hand, if the compatible mask opening information MAJ1 and the planned substrate pad information BPJ1 do not match, then the mask 4 where information is set for the planned substrate PB may not be suitable for use, and it is assumed that the settings of the substrate data BD need to be reviewed. In this case, the control unit CU outputs setting error information SE, which informs the operator or others that the settings of the substrate data BD need to be reviewed.

[0074] (Variations of judgment processing and printing processing) The control unit CU performs a determination process after the setting process is complete, when the substrate PB is supported by the support unit SU and the mask 4 is placed at the mask position MP. Referring to Figures 10 and 12, in the determination process, the control unit CU reads the substrate data BD, which contains the conforming mask aperture information MAJ1 and the planned substrate pad information BPJ1, from the storage unit MU (step b1). When the control unit CU recognizes that the mask 4 is placed at the mask position MP and the substrate PB is supported by the support unit SU (step b2), it causes the imaging unit CIU to capture an image of the mask 4 to be placed at the mask position MP, and also causes the imaging unit CIU to capture an image of the substrate PB to be supported by the support unit SU (step b3). The control unit CU performs image processing and other analysis processing on each image captured by the imaging unit CIU to create placement mask aperture information MAJ2 for each mask aperture 41 of the mask 4 to be placed, and support substrate pad information BPJ2 for each pad PB1 of the substrate PB to be supported (step b4). In this case, the control unit CU may create placement mask opening information MAJ2 in correspondence with mask openings 41 that have been assigned the information "Judgment Required" as the information on whether judgment is required in the conforming mask opening information MAJ1 set in the substrate data BD. Alternatively, the control unit CU may create support substrate pad information BPJ2 in correspondence with pads PB1 that have been assigned the information "Judgment Required" as the information on whether judgment is required in the planned substrate pad information BPJ1 set in the substrate data BD.

[0075] The placement mask opening information MAJ2 created by the control unit CU includes information about each mask opening 41 of the mask 4 to be placed, such as the shape, position, and size of each mask opening 41. The support substrate pad information BPJ2 created by the control unit CU includes information about each pad PB1 of the substrate PB to be supported, such as the shape, position, and size of each pad PB1.

[0076] The control unit CU then determines whether the placement mask aperture information MAJ2 for each mask aperture 41 of the mask 4 to be placed matches the conformance mask aperture information MAJ1 set in the substrate data BD (step b5). When the mask 4 to be placed is placed at the mask position MP, the control unit CU can determine whether the mask 4 to be placed is an appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB by determining whether the placement mask aperture information MAJ2 based on the image of the mask 4 to be placed captured by the imaging unit CIU matches the conformance mask aperture information MAJ1. Furthermore, the control unit CU determines whether the support substrate pad information BPJ2 for each pad PB1 of the substrate PB to be supported matches the plan substrate pad information BPJ1 set in the substrate data BD (step b5). When the substrate PB to be supported is supported by the support unit SU, the control unit CU can determine whether the substrate PB to be supported matches the planned substrate PB on which solder paste printing is planned, by determining whether the support substrate pad information BPJ2, based on the image of the substrate PB to be supported captured by the imaging unit CIU, matches the planned substrate pad information BPJ1.

[0077] If the determination result is obtained that the placement mask opening information MAJ2 matches the compatible mask opening information MAJ1 and the support substrate pad information BPJ2 matches the planned substrate pad information BPJ1 (YES in step b5), the control unit CU performs printing processing to cause the printing unit PU to perform printing operations based on the substrate data BD. If the placement mask opening information MAJ2 matches the compatible mask opening information MAJ1 and the support substrate pad information BPJ2 matches the planned substrate pad information BPJ1, it is determined that the substrate PB supported by the support unit SU matches the planned substrate PB, and the mask 4 placed at mask position MP is an appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB. The control unit CU can perform printing processing using an appropriate mask 4 according to the pattern of each pad PB1 on the substrate PB by performing printing processing according to such determination results.

[0078] If the determination result is obtained that the placement mask aperture information MAJ2 does not match the conforming mask aperture information MAJ1, or that the support substrate pad information BPJ2 does not match the planned substrate pad information BPJ1 (NO in step b5), it is determined whether a change operation to modify the conforming mask aperture information MAJ1 or the planned substrate pad information BPJ1 set in the substrate data BD has been received via the operation unit OU (step b6).

[0079] If a mask 4 whose mask opening 41 specifications have been changed due to a version upgrade or the like is placed at mask position MP, it is expected that a determination result will be obtained indicating that the placement mask opening information MAJ2 does not match the conforming mask opening information MAJ1. In such a situation, if a change operation is accepted via the operation unit OU (YES in step b6), the control unit CU updates the board data BD by changing the conforming mask opening information MAJ1 set in the board data BD to the placement mask opening information MAJ2 (step b7), and stores the updated board data BD in the storage unit MU (step b8). Also, if a board PB whose plan has been changed is supported by the support unit SU, it is expected that a determination result will be obtained indicating that the support board pad information BPJ2 does not match the planned board pad information BPJ1. In such a situation, if a change operation is accepted via the operation unit OU (YES in step b6), the control unit CU updates the board data BD by changing the planned board pad information BPJ1 set in the board data BD to the support board pad information BPJ2 (step b7), and stores the updated board data BD in the storage unit MU (step b8). The control unit CU can then perform printing operations, causing the printing unit PU to perform printing operations based on the updated board data BD stored in the memory unit MU.

[0080] If the placement mask opening information MAJ2 does not match the conforming mask opening information MAJ1, or if the support substrate pad information BPJ2 does not match the planned substrate pad information BPJ1, and no change operation has been accepted via the operation unit OU (NO in step b6), the control unit CU outputs the judgment error information JE (step b9) and stops the transition to the printing process (step b10). The control unit CU may display the outputted judgment error information JE on, for example, the display unit DU. If the placement mask opening information MAJ2 does not match the conforming mask opening information MAJ1, or if the support substrate pad information BPJ2 does not match the planned substrate pad information BPJ1, it is assumed that the mask 4 to be placed, placed at mask position MP, is not the correct mask 4 according to the pattern of each pad PB1 on the substrate PB, or that the substrate PB supported by the support unit SU does not match the planned substrate PB. In such cases, the control unit CU outputs judgment error information JE and stops the transition to the printing process. This allows the operator to be notified, in response to the output of judgment error information JE, that the mask 4 to be placed is not appropriate, or that the substrate PB to be supported does not match the planned substrate PB. It also prevents printing defects from occurring due to improperly printed solder paste on each pad PB1 on the substrate PB. [Explanation of Symbols]

[0081] 1 Printing device 4 Masks BD board data BPJ1 Planned PCB Pad Information BPJ2 Support Board Pad Information CU Control Unit CIU Imaging Unit MAJ1 Compatibility Mask Opening Information MAJ2 Placement Mask Aperture Information PU Printing Unit SU support unit

Claims

1. A printing apparatus for printing solder paste onto a substrate having pads on its surface, A support unit that supports the aforementioned substrate, A printing unit that includes a mask having a mask opening corresponding to the pads on the substrate, and performs a printing operation to print the solder paste onto the pads on the substrate supported by the support unit through the mask opening of the mask to be placed, which is positioned at a mask position above the support unit, An imaging unit capable of imaging the aforementioned mask, The system comprises a control unit that controls the support unit, the printing unit, and the imaging unit, The control unit is A setting process for setting suitable mask opening information regarding the mask opening of the suitable mask to substrate data in which information for identifying the substrate to be planned for printing the solder paste and information for identifying the suitable mask to be used on the substrate to be planned is pre-set, A determination process is performed to have the imaging unit capture an image of the mask to be placed, create placement mask aperture information relating to the mask aperture of the mask to be placed based on the image, and determine whether the placement mask aperture information matches the fitted mask aperture information. A printing apparatus that performs a printing process in which, according to the determination result of the determination process, the printing unit performs the printing operation based on the substrate data.

2. The printing apparatus according to claim 1, wherein the control unit, in the setting process, causes the imaging unit to capture an image of the mask to be fitted, and sets the fitted mask aperture information in the substrate data based on the image.

3. The printing apparatus according to claim 1, wherein the control unit, in the setting process, acquires design data including aperture design information relating to the mask aperture of the mask to be fitted, and sets the fitted mask aperture information in the substrate data based on the aperture design information.

4. The printing apparatus according to any one of claims 1 to 3, wherein the control unit, in the determination process, obtains the determination result that the arrangement mask opening information matches the conforming mask opening information, and then proceeds to the printing process.

5. The printing apparatus according to claim 4, wherein if the control unit obtains the determination result in the determination process that the arrangement mask opening information does not match the conforming mask opening information, it outputs determination error information and stops the transition to the printing process.

6. The control unit is In the determination process, if the determination result is obtained that the placement mask aperture information does not match the conforming mask aperture information, the substrate data is updated by changing the conforming mask aperture information set in the substrate data to the placement mask aperture information. The printing apparatus according to claim 4, wherein in the printing process, the printing unit is instructed to perform the printing operation based on the updated substrate data.

7. The imaging unit is capable of imaging the substrate in addition to the mask, In the setting process, the control unit, The imaging unit captures an image of the mask to be fitted, and based on that image, the fitted mask aperture information is set in the substrate data; and the imaging unit captures an image of the substrate to be planned, and based on that image, the planned substrate pad information for the pads of the substrate to be planned is set in the substrate data. The printing apparatus according to claim 1, wherein if the conforming mask opening information and the planned substrate pad information match, the process proceeds to the determination process, and if they do not match, setting error information is output.

8. The printing apparatus according to claim 7, wherein the control unit, in the determination process, determines whether the arrangement mask aperture information matches the conforming mask aperture information, causes the imaging unit to capture an image of the substrate to be supported, creates support substrate pad information relating to the pads of the substrate to be supported based on the image, and determines whether the support substrate pad information matches the planned substrate pad information.

9. The printing apparatus according to claim 8, wherein the control unit, in the determination process, obtains the determination result that the arrangement mask opening information matches the conforming mask opening information and the support substrate pad information matches the planned substrate pad information, and then proceeds to the printing process.

10. The printing apparatus according to claim 9, wherein if the control unit obtains the determination result in the determination process that the arrangement mask opening information does not match the conforming mask opening information, or that the support substrate pad information does not match the planned substrate pad information, it outputs determination error information and stops the transition to the printing process.

11. The control unit is In the determination process, if the determination result is obtained that the placement mask aperture information does not match the conforming mask aperture information, the substrate data is updated by changing the conforming mask aperture information set in the substrate data to the placement mask aperture information. In the determination process, if the determination result is obtained that the support substrate pad information does not match the planned substrate pad information, the substrate data is updated by changing the planned substrate pad information set in the substrate data to the support substrate pad information. The printing apparatus according to claim 9, wherein in the printing process, the printing unit is instructed to perform the printing operation based on the updated substrate data.

12. A printing apparatus comprising: a support unit for supporting a substrate having pads on its surface; a printing unit disposed at a mask position above the support unit and including a mask having mask openings corresponding to the pads on the substrate; and an imaging unit capable of imaging the mask, wherein a printing method is provided for printing solder paste onto the pads on the substrate supported by the support unit through the mask openings of the mask to be placed at the mask position in accordance with the printing operation of the printing unit, A setting step of setting suitable mask opening information for the mask opening of the suitable mask to substrate data in which information for identifying the substrate to be planned for printing the solder paste and information for identifying the suitable mask to be used on the substrate to be planned are pre-set, A determination step of having the imaging unit capture an image of the mask to be placed, creating placement mask aperture information relating to the mask aperture of the mask to be placed based on the image, and determining whether the placement mask aperture information matches the conforming mask aperture information. A printing method comprising: a printing step of causing the printing unit to perform the printing operation based on the substrate data according to the determination result of the determination step.

Images