Printing apparatus

Abstract

To provide a printing device that can estimate deviations of an amount of movement of a solder transfer sheet for collecting and supplying solder paste with respect to a mask, from a reference amount of movement.SOLUTION: A printing device 1 comprises: a mask 4 arranged above a substrate P; a squeegee 6a that prints solder paste SP on the substrate P by moving the solder paste SP on the mask 4; a solder transfer sheet 52 that performs collection operation which collects the solder paste SP from the top of the mask 4 by circling and moving by a predetermined reference amount of movement SL in a first direction D1 and supplying operation which supplies the collected solder paste SP to the top of the mask 4 by circling and moving by the predetermined reference amount of movement SL in a second direction D2; a detecting part 8a that detects an object to be detected on the solder transfer sheet 52, at a predetermined reference position P1; and a position deviation recognizing part 301 that recognizes an amount of positional deviation of the object to be detected on the solder transfer sheet 52 with respect to the reference position P1, on the basis of a detected result by the detecting part 8a.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a printing apparatus for printing solder paste on a substrate such as a printed circuit board.

Background Art

[0002] Conventionally, a screen printing apparatus is known which prints a solder paste such as cream solder supplied onto a mask onto a substrate such as a printed circuit board overlaid on the mask while moving the solder paste along the mask by a squeegee that moves along the mask.

[0003] As one of this type of screen printing apparatus, for example, Patent Document 1 discloses a printing apparatus provided with a solder lifting and lowering apparatus including a solder transfer sheet for temporarily collecting the solder paste on the mask and supplying the collected solder paste onto the mask after the mask is exchanged when the mask is exchanged due to a change in the type of substrate or the like. In this printing apparatus, the solder transfer sheet is wound around a plurality of rollers, and the solder transfer sheet moves in a circular motion in response to the rotation of the rollers. By moving the solder transfer sheet in a circular motion by a predetermined reference movement amount, the collection of the solder paste from the mask to the sheet and the supply of the solder paste from the sheet to the mask are performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] If the solder transfer sheet used for collecting and supplying solder paste to the mask experiences bending or vibration, the amount of movement of the solder transfer sheet during its circumferential movement may become unstable. In this case, the amount of movement of the solder transfer sheet during the collection and supply of solder paste to the mask may deviate from the reference amount. If the amount of movement of the solder transfer sheet deviates from the reference amount, it becomes difficult to collect the solder paste from the mask to the correct position on the sheet, and it also becomes difficult to supply the collected solder paste to the correct position on the mask.

[0006] The object of the present invention is to provide a printing apparatus capable of estimating the amount of deviation of the movement of a solder transfer sheet relative to a reference movement amount for collecting and supplying solder paste to a mask. [Means for solving the problem]

[0007] A printing apparatus according to one aspect of the present invention is an apparatus for printing solder paste on a substrate. The printing apparatus comprises a mask having a printing opening and being interchangeably disposed above the substrate; a squeegee that moves the solder paste on the mask to print the solder paste on the substrate through the printing opening; a solder transfer sheet that extends in the longitudinal direction and is provided to be circumferentially movable in a first direction along the longitudinal direction and in a second direction opposite to the first direction, and performs a recovery operation to recover the solder paste from the mask by circumferentially moving the sheet in the first direction by a predetermined reference movement amount and a supply operation to supply the recovered solder paste onto the mask by circumferentially moving the sheet in the second direction by the reference movement amount; a detection unit that detects a target to be detected on the solder transfer sheet at a predetermined reference position; and a positional deviation recognition unit that recognizes the amount of positional deviation of the target to be detected on the solder transfer sheet relative to the reference position based on the detection result of the detection unit.

[0008] In this printing apparatus, when the mask is changed due to a change in the type of substrate to be printed with solder paste using a squeegee, the solder transfer sheet performs a retrieval operation and a supply operation. In the retrieval operation, the solder transfer sheet retrieves solder paste from the mask by moving around in a first direction by a predetermined reference movement amount, and in the supply operation, it supplies the retrieved solder paste onto the mask by moving around in a second direction by a reference movement amount. At this time, the positional displacement recognition unit recognizes the amount of positional displacement of the detected object on the solder transfer sheet relative to the reference position, based on the detection result of the detection unit on the solder transfer sheet. Based on this amount of positional displacement of the detected object on the solder transfer sheet, it is possible to estimate the amount of displacement of the circumferential movement of the solder transfer sheet relative to the reference movement amount. Furthermore, by estimating the deviation of the solder transfer sheet's movement relative to a reference movement, it is possible to estimate the deviation of the solder paste collected on the solder transfer sheet relative to the appropriate collection position in accordance with the solder transfer sheet's retrieval operation, and also to estimate the deviation of the solder paste supplied onto the mask relative to the appropriate supply position in accordance with the solder transfer sheet's supply operation.

[0009] In the above-described printing apparatus, the detection unit may detect the object to be detected when the circular movement of the solder transfer sheet is stopped.

[0010] In this embodiment, the detection unit detects the target object when the circumferential movement of the solder transfer sheet is stopped. In this case, the detection unit can detect the target object on the solder transfer sheet while external disturbances such as vibrations associated with the circumferential movement of the solder transfer sheet are eliminated. This improves the detection accuracy of the detection unit.

[0011] In the above-described printing apparatus, the detection unit may include at least one of a camera that detects the object to be detected based on an image, and a laser sensor that detects the object to be detected based on laser light.

[0012] In this embodiment, a camera and a laser sensor can be used as detection units for detecting objects on the solder transfer sheet.

[0013] In the above-described printing apparatus, the object to be detected may be a plurality of markers consisting of a plurality of marks or holes provided at a certain interval in the longitudinal direction on the solder transfer sheet. In this case, the detection unit performs a first marker detection operation to detect the markers at the reference position before the recovery operation by the solder transfer sheet, and a second marker detection operation to detect the markers at the reference position after the recovery operation by the solder transfer sheet and before the supply operation. The position misalignment recognition unit performs a first recognition process to recognize the amount of position misalignment of the first marker as the amount of position misalignment based on the detection result of the first marker detection operation of the detection unit, and a second recognition process to recognize the amount of position misalignment of the second marker as the amount of position misalignment based on the detection result of the second marker detection operation of the detection unit.

[0014] In this embodiment, before the retrieval operation using the solder transfer sheet, the detection unit performs a first mark detection operation to detect a mark on the solder transfer sheet, and the positional deviation recognition unit performs a first recognition process to recognize the amount of first mark positional deviation based on the detection result of the first mark detection operation. In this case, the amount of first mark positional deviation can be determined as the amount of positional deviation of the mark on the solder transfer sheet relative to the reference position before the retrieval operation using the solder transfer sheet. Then, after the retrieval operation using the solder transfer sheet and before the supply operation, the detection unit performs a second mark detection operation to detect a mark on the solder transfer sheet, and the positional deviation recognition unit performs a second recognition process to recognize the amount of second mark positional deviation based on the detection result of the second mark detection operation. In this case, it is possible to estimate the amount of deviation of the circumferential movement in the retrieval operation of the solder transfer sheet relative to the reference movement amount based on the amount of second mark positional deviation. This makes it possible to estimate the amount of retrieval positional deviation of the solder paste retrieved on the solder transfer sheet relative to the appropriate retrieval position in accordance with the retrieval operation of the solder transfer sheet.

[0015] In the above-described printing apparatus, the reference movement amount is set according to the solder roll width, which indicates the width of the solder roll that is a mass of solder paste on the mask, and the spacing between adjacent markings on the solder transfer sheet may be set to a value obtained by adding a predetermined margin to the solder roll width.

[0016] In this embodiment, the reference movement amount in the retrieval and supply operations of the solder transfer sheet is set according to the solder roll width of the solder paste on the mask, and the spacing between multiple markers on the solder transfer sheet is set to a value obtained by adding a predetermined margin to the solder roll width. In this case, both the reference movement amount and the spacing between the markers are set based on the solder roll width. Therefore, the spacing between multiple markers on the solder transfer sheet is set to a value corresponding to the reference movement amount. In this case, after the solder transfer sheet has moved around by the reference movement amount in the retrieval operation, it is possible to position one of the multiple markers on the solder transfer sheet within the detection range of the detection unit. As a result, in the second marker detection operation, which is after the retrieval operation by the solder transfer sheet and before the supply operation, the detection unit can accurately detect one marker on the solder transfer sheet.

[0017] In the above-described printing apparatus, the spacing between adjacent markings on the solder transfer sheet may be set to be the same as the reference movement amount.

[0018] In this embodiment, the spacing between multiple markers on the solder transfer sheet is set to be the same as the reference movement amount. In this case, after the solder transfer sheet has moved around by the reference movement amount during the retrieval operation, it is possible to more reliably position one of the multiple markers on the solder transfer sheet within the detection range of the detection unit. As a result, in the second marker detection operation, which occurs after the retrieval operation by the solder transfer sheet and before the supply operation, the detection unit can more accurately detect one marker on the solder transfer sheet.

[0019] The above-described printing apparatus may further include a control unit that controls the circumferential movement of the solder transfer sheet. In this case, the control unit performs a first position misalignment correction process to correct the position of the mark portion relative to the reference position by moving the solder transfer sheet circumferentially according to the amount of the first mark position misalignment, before the recovery operation by the solder transfer sheet, and a second position misalignment correction process to correct the position of the mark portion relative to the reference position by moving the solder transfer sheet circumferentially according to the amount of the second mark position misalignment, after the recovery operation by the solder transfer sheet and before the supply operation.

[0020] In this embodiment, the control unit performs a first positional misalignment correction process to move the solder transfer sheet around the solder transfer sheet according to the amount of first marker positional misalignment recognized in the first recognition process by the positional misalignment recognition unit, before the retrieval operation using the solder transfer sheet. This allows the position of the marker on the solder transfer sheet relative to the reference position to be corrected before the retrieval operation using the solder transfer sheet. In this case, the retrieval operation using the solder transfer sheet is performed with the position of the marker on the solder transfer sheet corrected. After the retrieval operation using the solder transfer sheet and before the supply operation, the control unit performs a second positional misalignment correction process to move the solder transfer sheet around the solder transfer sheet according to the amount of second marker positional misalignment recognized in the second recognition process by the positional misalignment recognition unit. This allows the position of the marker on the solder transfer sheet relative to the reference position to be corrected after the retrieval operation using the solder transfer sheet and before the supply operation. In this case, the position of the solder paste collected on the solder transfer sheet can be corrected according to the amount of deviation from the reference movement amount of the circumferential movement during the retrieval operation of the solder transfer sheet, which corresponds to the amount of deviation of the second marker position. This makes it possible to position the solder paste collected on the solder transfer sheet at the correct retrieval position in accordance with the retrieval operation of the solder transfer sheet. When the solder paste collected on the solder transfer sheet is in the correct retrieval position in this way, the solder transfer sheet moves circumferentially by the reference movement amount during the supply operation of the solder transfer sheet, making it possible to supply the solder paste on the solder transfer sheet to the correct supply position on the mask.

[0021] In the above-described printing apparatus, the object to be detected may be a recovered solder roll, which is a mass of solder paste recovered onto the solder transfer sheet by the recovery operation. In this case, the detection unit performs a recovered solder detection operation to detect the recovered solder roll at the reference position after the recovery operation by the solder transfer sheet and before the supply operation. The positional displacement recognition unit recognizes the amount of recovered solder displacement as the amount of positional displacement based on the detection result of the recovered solder detection operation of the detection unit.

[0022] In this embodiment, after the retrieval operation by the solder transfer sheet and before the supply operation, the detection unit performs a retrieval solder detection operation to detect a retrieval solder roll, which is a mass of solder paste retrieved onto the solder transfer sheet in accordance with the retrieval operation. The positional displacement recognition unit recognizes the amount of retrieval solder displacement based on the detection result in the retrieval solder detection operation. In this case, based on the amount of retrieval solder displacement, it is possible to estimate the amount of displacement of the circumferential movement of the solder transfer sheet in the retrieval operation relative to the reference movement amount, and it is also possible to estimate the amount of retrieval position displacement of the solder paste retrieved onto the solder transfer sheet in accordance with the retrieval operation relative to the appropriate retrieval position.

[0023] The above-described printing apparatus may further include a control unit that controls the circumferential movement of the solder transfer sheet. In this case, the control unit performs a positional misalignment correction process to correct the position of the recovered solder roll relative to the reference position by moving the solder transfer sheet circumferentially according to the amount of the recovered solder misalignment, after the recovery operation by the solder transfer sheet and before the supply operation.

[0024] In this aspect, after the recovery operation by the solder transfer sheet and before the supply operation, the control unit performs a position deviation correction process of circularly moving the solder transfer sheet according to the amount of recovery solder position deviation recognized by the position deviation recognition unit. Thereby, after the recovery operation by the solder transfer sheet and before the supply operation, the position of the recovery solder roll on the solder transfer sheet with respect to the reference position can be corrected. In this case, according to the amount of recovery solder position deviation, the position of the solder paste recovered on the solder transfer sheet can be corrected. Thereby, the solder paste recovered on the solder transfer sheet according to the recovery operation of the solder transfer sheet can be positioned at an appropriate recovery position. In a state where the solder paste recovered on the solder transfer sheet is positioned at the appropriate recovery position in this way, in the supply operation of the solder transfer sheet, by circularly moving the solder transfer sheet by the reference movement amount, the solder paste on the solder transfer sheet can be supplied to the appropriate supply position on the mask.

[0025] In the above printing apparatus, the detection target may be a solder trace indicating the trace of the solder paste remaining on the solder transfer sheet after the supply operation by the solder transfer sheet. In this case, the detection unit performs a solder trace detection operation of detecting the solder trace at the reference position after the supply operation by the solder transfer sheet. The position deviation recognition unit recognizes the amount of solder trace position deviation as the amount of position deviation based on the detection result in the solder trace detection operation of the detection unit.

[0026] In this aspect, after the supply operation by the solder transfer sheet, the detection unit performs a solder trace detection operation of detecting a solder trace indicating the trace of the solder paste remaining on the solder transfer sheet, and the position deviation recognition unit recognizes the amount of solder trace position deviation based on the detection result in the solder trace detection operation. In this case, based on the amount of solder trace position deviation, it is possible to estimate the deviation amount of the movement amount of the circular movement in the supply operation of the solder transfer sheet with respect to the reference movement amount, and it is possible to estimate the supply position deviation amount with respect to the appropriate supply position of the solder paste supplied from the solder transfer sheet onto the mask according to the supply operation.

[0027] The above-described printing apparatus may further include a solder width measurement unit that measures the width of a solder roll, which is a lump of the solder paste on the mask, on the mask, and a control unit that controls the solder width measurement unit and controls the squeegee. In this case, after the supply operation by the solder transfer sheet, the control unit adjusts the measurement position of the solder width measurement unit based on the amount of displacement of the solder trace position, and adjusts the movement start position when the squeegee moves the solder paste on the mask.

[0028] In this aspect, after the supply operation by the solder transfer sheet, the control unit adjusts the measurement position of the solder width measurement unit that measures the width of a solder roll, which is a lump of the solder paste on the mask, based on the amount of displacement of the solder trace position recognized by the displacement recognition unit, and adjusts the movement start position when the squeegee moves the solder paste on the mask. By adjusting the measurement position of the solder width measurement unit based on the amount of displacement of the solder trace position, the solder width measurement unit can accurately measure the width of the solder roll, which is a lump of the solder paste on the mask. Further, by adjusting the movement start position of the squeegee based on the amount of displacement of the solder trace position, it is possible to suppress the shape of the solder roll, which is a lump of the solder paste on the mask, from being broken by the squeegee when the squeegee is disposed at the movement start position.

Effect of the Invention

[0029] As described above, according to the present invention, it is possible to provide a printing apparatus capable of estimating the amount of deviation of the movement amount of a solder transfer sheet for recovering and supplying a solder paste to a mask from a reference movement amount.

Brief Description of the Drawings

[0030] [Figure 1] It is a side view of a printing apparatus according to a first embodiment of the present invention. [Figure 2] It is a front view of the printing apparatus of FIG. 1. [Figure 3] It is a side view showing a schematic configuration of a solder transfer unit provided in a printing apparatus. [Figure 4]This is a plan view showing the solder transfer sheet provided in the solder transfer unit. [Figure 5] This is a flowchart showing the processing flow of the solder transfer process in the printing apparatus according to the first embodiment. [Figure 6] This diagram illustrates each step of the solder transfer process in a printing apparatus according to the first embodiment, and further illustrates the first mark detection process, the first recognition process, the first positional misalignment correction process, and the solder recovery process. [Figure 7] This diagram illustrates each step of the solder transfer process in a printing apparatus according to the first embodiment, and further illustrates the second mark detection process, the second recognition process, the second positional misalignment correction process, and the solder supply process. [Figure 8] This is a plan view showing the positional relationship between the solder transfer unit and the detection unit in a printing apparatus according to a second embodiment of the present invention. [Figure 9] This is a flowchart showing the processing flow of the solder transfer process in the printing apparatus according to the second embodiment. [Figure 10] This diagram illustrates each step of the solder transfer process in a printing apparatus according to the second embodiment, and further illustrates the solder recovery process, the recovered solder detection process, and the recognition process. [Figure 11] This diagram illustrates each step of the solder transfer process in a printing apparatus according to the second embodiment, and further illustrates the misalignment correction process and the solder supply process. [Figure 12] This is a flowchart showing the processing flow of the solder transfer process in a printing apparatus according to the third embodiment of the present invention. [Figure 13] This diagram illustrates each step of the solder transfer process in a printing apparatus according to the third embodiment, and further illustrates the solder recovery process, solder supply process, solder trace detection process, and recognition process. [Modes for carrying out the invention]

[0031] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0032] (First Embodiment) The printing apparatus 1 according to the first embodiment will be described with reference to Figures 1 to 7. In the following, directional relationships will be explained using XYZ Cartesian coordinates.

[0033] The 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 direction. In the printing apparatus 1, substrates P such as printed circuit boards are transported to the printing stage 3 by the input conveyor 2a, where a printing process to print solder paste is performed, and then the substrate is discharged by the output conveyor 2b.

[0034] A four-axis unit 10 is installed on the printing stage 3. The four-axis unit 10 supports the substrate P and loads the substrate P onto the mask 4 (described later) from below. It horizontally supports the substrate P that has been brought in by the transport conveyor 2a and supports it so that it can be displaced in the X, Y, Z, and R (around the Z axis) directions.

[0035] Specifically, the 4-axis unit 10 is hierarchically comprised of, from bottom to top, a fixed table 11 fixed on a base 1A, an X-axis table 12 that can move in the X direction relative to the fixed table 11, a Y-axis table 13 that can move in the Y direction relative to the X-table 12, an R-axis table 14 that can rotate around the Z-axis relative to the Y-axis table 13, and a lifting table 15 that can move up and down in the Z direction relative to the R-axis table 14. A support unit 16 is mounted on the lifting table 15, and the substrate P is supported by this support unit 16, so that the substrate P moves in the X, Y, Z, and R directions by driving each of the tables 12, 13, 14, and 15.

[0036] The support unit 16 includes a conveyor 19 that supports the substrate P so that it can be transported in the Y direction, a support mechanism 17 for supporting the substrate P, and a clamping mechanism 18 for clamping the substrate P. Specifically, the support unit 16 receives the substrate P from the input conveyor 2a onto the conveyor 19, lifts the substrate P from the conveyor 19 by supporting it from below with the support mechanism 17, and clamps the substrate P from both sides in the X direction with the clamping mechanism 18. This positions and fixes the substrate P in a predetermined position on the lifting table 15.

[0037] A mask 4 is positioned almost horizontally above the printing stage 3. The mask 4 is replaceably positioned above the substrate P on the printing stage 3. The mask 4 is a plate-like member, for example, made of stainless steel, with printing openings formed therein. It is stretched over a predetermined frame and then removably 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. As the printing process progresses, the 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 printing openings. During the printing process, the cleaning device 9 is positioned in a predetermined retracted position outside the mask 4.

[0038] A detection unit 8 is positioned below the mask 4. The detection unit 8 is supported so as to be movable in the X direction and is driven by a servo motor or the like. The detection unit 8 is equipped with a detection section 8a. The detection section 8a detects the mask 4 from below. Based on the detection result of the detection section 8a, the position of the mask 4 is recognized. In the printing apparatus 1, after the relative position of the substrate P with respect to the mask 4 is recognized based on the detection result of the detection section 8a, the relative position of the substrate P 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 10 of the printing stage 3. Then, in the printing apparatus 1, with the relative position of the substrate P with respect to the mask 4 precisely positioned, the substrate P is raised by driving the lifting table 15 in the 4-axis unit 10 and comes into contact with the lower surface of the mask 4.

[0039] Furthermore, the detection unit 8a of the detection unit 8 detects the object to be detected on the solder transfer sheet 52 equipped on the solder transfer unit 5 described later. In this case, the detection unit 8a includes at least one of a camera that detects the object based on an image and a laser sensor that detects the object based on laser light. In this embodiment, the detection unit 8a is a camera that detects the object based on an image.

[0040] A squeegee unit 6 is positioned above the mask 4. The squeegee unit 6 is a unit for printing solder paste, such as solder paste, onto the substrate P through the printing opening of the mask 4 by moving the solder paste along the mask 4.

[0041] The squeegee unit 6 is supported so as to be movable in the X 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 direction, a unit support member 21 extending in the Y direction and supported so as to be movable on each fixed rail 21, 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 direction together with the unit support member 21 by the drive of the servo motor 20A.

[0042] 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 direction relative to the squeegee unit 6. The squeegee 6a spreads the solder paste on the mask 4 and moves along the mask 4, and is made of, for example, a long, narrow rigid urethane or stainless steel plate member in the Y direction. The squeegee 6a is pressed against the mask 4 by descending in the Z direction relative to the squeegee unit 6, and in this state, the squeegee unit 6 moves in the X direction together with the unit support member 21, causing the squeegee 6a to slide along the mask 4. In this way, as the squeegee 6a slides along the mask 4, the solder paste supplied to the mask 4 is moved in the X direction, and the solder paste is printed onto the substrate P through the printing opening of the mask 4.

[0043] The squeegee 6a is pivotably supported relative to the squeegee unit 6. The squeegee 6a can be switched between a state where the solder paste pressing surface faces one side in the X direction and a state where it faces the other side, and the angle between the pressing surface and the mask 4 can be changed. In other words, as the squeegee unit 6 moves back and forth in the X direction, the position of the squeegee 6a is switched so that the pressing surface faces the direction of travel during the forward and reverse movements, respectively, so that printing during the forward movement and printing during the reverse movement of the squeegee unit 6 are performed with a single squeegee 6a.

[0044] The unit support member 21 is equipped with a solder transfer unit 5 in addition to the squeegee unit 6. The solder transfer unit 5 is movable in the X direction integrally with the unit support member 21 by the drive of a servo motor 20A. The solder transfer unit 5 is a unit that collects the solder paste on the mask 4 when the mask 4 is replaced, such as when changing the type of substrate P to which the solder paste is printed by the squeegee 6a, and supplies the collected solder paste onto the replaced mask 4.

[0045] As shown in Figure 3, the solder transfer unit 5 includes a scraper 51 and a solder transfer sheet 52.

[0046] The scraper 51 is a component that serves as the base for collecting and supplying solder paste SP to the mask 4. The scraper 51 is supported by a support member 51a. The support member 51a is connected to a drive mechanism 22 that drives the support member 51a in the X and Z directions using a servo motor 23 shown in Figure 2 as the drive source. As a result, the scraper 51 can move in one direction in the X direction, a first X direction DD1 and the other direction in the X direction, and can move up and down in the Z direction, together with the support member 51a via the drive mechanism 22 driven by the servo motor 23.

[0047] The solder transfer sheet 52 is a sheet that extends longitudinally to cover the scraper 51. The solder transfer sheet 52 is wrapped around the first support roller 53 and the second support roller 55 so that it can move circumferentially in a first direction D1 along the longitudinal direction and in a second direction D2 opposite to the first direction D1, while covering the scraper 51. One end of the solder transfer sheet 52 in the longitudinal direction is connected to a first support shaft 54 ​​that supports a sheet roll 52a, which is the wound body of the solder transfer sheet 52, and the other end in the longitudinal direction is connected to a second support shaft 56 that supports the sheet roll 52a. The first support shaft 54 ​​and the second support shaft 56 are rotationally driven by a drive motor 24 such as a servo motor shown in Figure 2. The solder transfer sheet 52 is pressed by the pressing member 57 so that the portion covering the scraper 51 conforms to the shape of the scraper 51. The first support shaft 54 ​​is rotated by the drive motor 24, causing the sheet to rotate in a first direction D1, and the second support shaft 56 is rotated by the drive motor 24, causing the sheet to rotate in a second direction D2.

[0048] The solder transfer sheet 52 performs both a retrieval and a supply operation while in contact with the mask 4 as the scraper 51 descends. In the retrieval operation, the solder transfer sheet 52 retrieves solder paste SP from the mask 4 by circulating in a first direction D1 with a predetermined reference movement amount SL. When the retrieval operation by the solder transfer sheet 52 is performed, the scraper 51 moves in a first X direction DD1, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51 as it circulates in the first direction D1. This allows the solder paste SP to be retrieved from the mask 4 onto the solder transfer sheet 52 without damaging the shape of the solder roll, which is a mass of solder paste SP formed into a roll shape by mixing the solder paste SP. On the other hand, in the supply operation, the solder transfer sheet 52 supplies the retrieved solder paste SP onto the mask 4 by circulating in a second direction D2 with a predetermined reference movement amount SL. When the solder transfer sheet 52 is used for supply, the scraper 51 moves in the second X direction DD2, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51, which moves in the second direction D2. This allows the solder paste SP on the solder transfer sheet 52 to be supplied onto the mask 4 without distorting the shape of the solder roll, which is a mass of solder paste SP.

[0049] The reference movement amount SL when the solder transfer sheet 52 moves around during the retrieval and supply operations is set according to the solder roll width SW, which indicates the width of the solder roll, a mass of solder paste SP on the mask 4. For example, if the solder roll width SW is about 10mm to 20mm, the reference movement amount SL is set to about 33mm, which is slightly larger than the solder roll width SW.

[0050] When the solder transfer sheet 52 in the solder transfer unit 5 performs collection and supply operations, the detection unit 8a in the detection unit 8 performs a detection operation. The detection unit 8a detects the object to be detected on the solder transfer sheet 52. At this time, the detection unit 8 moves in the X direction so that the detection unit 8a is positioned at a predetermined reference position P1. That is, the detection unit 8a detects the object to be detected on the solder transfer sheet 52 at the predetermined reference position P1. The detection unit 8a detects the object to be detected on the solder transfer sheet 52 while the rotational movement of the solder transfer sheet 52 is stopped. In this case, the detection unit 8a can detect the object to be detected on the solder transfer sheet 52 while external disturbances such as vibrations associated with the rotational movement of the solder transfer sheet 52 are eliminated. This improves the detection accuracy of the detection unit 8a.

[0051] In this embodiment, the detection targets on the solder transfer sheet 52 are multiple marker portions 52M, which consist of multiple marks or holes provided on the solder transfer sheet 52 at a constant interval PT in the longitudinal direction, as shown in Figure 4. Among the multiple marker portions 52M provided on the solder transfer sheet 52, the interval PT between adjacent marker portions 52M is set to a value obtained by adding a predetermined margin value MG to the solder roll width SW, which indicates the width of the solder roll, which is a mass of solder paste SP on the mask 4. For example, if the solder roll width SW is about 10 mm to 20 mm, the margin value MG is set to within about 20 mm. In this case, the interval PT between adjacent marker portions 52M is set to, for example, about 20 mm to 40 mm.

[0052] The reference movement amount SL in the retrieval and supply operations of the solder transfer sheet 52 is set according to the solder roll width SW of the solder paste SP on the mask 4, and the spacing PT between the multiple markers 52M on the solder transfer sheet 52 is set to a value obtained by adding a predetermined margin value MG to the solder roll width SW. In this case, both the reference movement amount SL and the spacing PT between the markers 52M are set based on the solder roll width SW. Therefore, the spacing PT between the multiple markers 52M on the solder transfer sheet 52 is set to a value corresponding to the reference movement amount SL. In this case, after the solder transfer sheet 52 has moved around by the reference movement amount SL in the retrieval and supply operations, it is possible to position one of the multiple markers 52M on the solder transfer sheet 52 within the detection range DR (Figures 6, 7) of the detection unit 8a. As a result, the detection unit 8a can accurately detect one marker 52M on the solder transfer sheet 52.

[0053] Furthermore, it is preferable that the spacing PT between the multiple markers 52M on the solder transfer sheet 52 be set to be the same as the reference movement amount SL during the retrieval and supply operations of the solder transfer sheet 52. In this case, after the solder transfer sheet 52 has moved around by the reference movement amount SL during the retrieval and supply operations, it is possible to more reliably position one of the multiple markers 52M on the solder transfer sheet 52 within the detection range DR of the detection unit 8a. As a result, the detection unit 8a can more accurately detect one marker 52M on the solder transfer sheet 52.

[0054] As shown in Figure 1, the squeegee unit 6 is provided with a solder width measuring unit 6b for measuring the solder roll width SW, which is the width of the solder roll, a mass of solder paste SP on the mask 4.

[0055] As shown in Figure 1, the printing apparatus 1 is equipped with a control unit 30 that comprehensively controls the operation of each unit installed in the printing apparatus 1. The control unit 30 is a personal computer that has a CPU (Central Processing Unit), storage areas such as an HDD (Hard Disk Drive) and flash memory for storing control programs, and RAM (Random Access Memory) used as the CPU's workspace. For example, the control unit 30 executes a solder width measurement process that controls the solder width measuring unit 6b by having the CPU execute a control program stored in the HDD or flash memory, as well as a printing process that controls the squeegee unit 6, and further controls the solder transfer unit 5 and the detection unit 8 to execute a solder transfer process that involves collecting and supplying solder paste SP to the mask 4.

[0056] The control unit 30 performs a solder transfer process when the mask 4 is replaced, such as when the type of substrate P to which solder paste is printed by the squeegee 6a is changed. The control unit 30 includes a position misalignment recognition unit 301 and a control unit 302 as functional components for performing the solder transfer process.

[0057] The control unit 302 controls the operation of the solder transfer unit 5 and the detection unit 8 during the solder transfer process. Specifically, the control unit 302 controls various operations such as the movement of the solder transfer unit 5 in the X direction, the movement of the scraper 51 in the X direction and the raising and lowering movement in the Z direction, the circumferential movement of the solder transfer sheet 52 for collection and supply, the movement of the detection unit 8 in the X direction, and the detection operation of the detection unit 8a. In addition, the control unit 302 controls the measurement operation of the solder width measuring unit 6b during the solder width measurement process, and controls the movement of the squeegee unit 6 in the X direction and the raising and lowering movement of the squeegee 6a in the Z direction during the printing process.

[0058] In the solder transfer process of the control unit 302, the detection unit 8a detects the marker portion 52M, which is the target for detection on the solder transfer sheet 52, at a predetermined reference position P1 (Figures 6 and 7) while the circular movement of the solder transfer sheet 52 is stopped.

[0059] The positional displacement recognition unit 301 recognizes the amount of positional displacement of the target marker portion 52M on the solder transfer sheet 52 relative to the reference position P1, based on the detection result of the detection unit 8a. Based on this amount of positional displacement of the target marker portion 52M on the solder transfer sheet 52, it is possible to estimate the amount of displacement of the circumferential movement of the solder transfer sheet 52 relative to the reference movement amount SL. Furthermore, by estimating the amount of displacement of the movement of the solder transfer sheet 52 relative to the reference movement amount SL, it is possible to estimate the amount of displacement of the collection position of the solder paste SP collected on the solder transfer sheet 52 relative to the appropriate collection position in accordance with the collection operation of the solder transfer sheet 52, and it is possible to estimate the amount of displacement of the supply position of the solder paste SP supplied on the mask 4 relative to the appropriate supply position in accordance with the supply operation of the solder transfer sheet 52.

[0060] The solder transfer process performed by the control unit 30 will be explained in detail with reference to Figures 5 to 7.

[0061] The control unit 30 performs the following processes during the solder transfer process: first marker detection process a1, first recognition process a2, first positional misalignment correction process a3, solder retrieval process a4, second marker detection process a5, second recognition process a6, second positional misalignment correction process a7, and solder supply process a8. In the control unit 30, the first recognition process a2 and the second recognition process a6 are performed by the positional misalignment recognition unit 301, while the other processes are performed by the control unit 302.

[0062] When the control unit 302 executes the first marker detection process a1, the detection unit 8 moves in the X direction so that the detection unit 8a is positioned at the reference position P1. The solder transfer unit 5 also moves in the X direction so that the marker portion 52M on the solder transfer sheet 52 is positioned at the reference position P1. With the solder transfer unit 5 positioned at the reference position P1, the scraper 51 descends in the Z direction to a predetermined position above the detection unit 8a. In this state, the detection unit 8a performs a first marker detection operation to detect the marker portion 52M at the reference position P1 before the retrieval operation by the solder transfer sheet 52.

[0063] In the first recognition process a2 following the first marker detection process a1, the positional displacement recognition unit 301 recognizes the first marker positional displacement amount ML1 as the amount of positional displacement of the marker portion 52M to be detected on the solder transfer sheet 52 relative to the reference position P1, based on the detection result in the first marker detection operation of the detection unit 8a. In this case, the first marker positional displacement amount ML1 can be determined as the amount of positional displacement of the marker portion 52M on the solder transfer sheet 52 relative to the reference position P1, before the retrieval operation by the solder transfer sheet 52.

[0064] In the first positional misalignment correction process a3 following the first recognition process a2, the control unit 302 corrects the position of the marker portion 52M relative to the reference position P1 by moving the solder transfer sheet 52 in a circular motion according to the first marker positional misalignment amount ML1, before the retrieval operation by the solder transfer sheet 52. This allows the position of the marker portion 52M on the solder transfer sheet 52 relative to the reference position P1 to be corrected before the retrieval operation by the solder transfer sheet 52. In this case, the retrieval operation by the solder transfer sheet 52 can be performed with the position of the marker portion 52M on the solder transfer sheet 52 corrected. Once the position of the marker portion 52M on the solder transfer sheet 52 relative to the reference position P1 is corrected, the control unit 302 raises the scraper 51.

[0065] After the first misalignment correction process a3, when the control unit 302 executes the solder recovery process a4, the solder transfer unit 5 moves in the X direction to reach a predetermined recovery position P2. With the solder transfer unit 5 positioned at the recovery position P2, the scraper 51 descends in the Z direction so that the solder transfer sheet 52 contacts the mask 4. In this state, the solder transfer sheet 52 performs a recovery operation to recover solder paste SP from the mask 4 by moving in a circumferential manner in the first direction D1 with a predetermined reference movement amount SL. When the recovery operation by the solder transfer sheet 52 is performed, the scraper 51 moves in the first X direction DD1, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51 as it moves in a circumferential manner in the first direction D1. This makes it possible to recover solder paste SP from the mask 4 onto the solder transfer sheet 52 without distorting the shape of the solder roll, which is a mass of solder paste SP. Once the retrieval operation of the solder transfer sheet 52 is complete, the control unit 302 raises the scraper 51.

[0066] After the solder recovery process a4, when the control unit 302 executes the second marker detection process a5, the detection unit 8 moves in the X direction so that the detection unit 8a is positioned at the reference position P1. The solder transfer unit 5 also moves in the X direction so that the marker portion 52M on the solder transfer sheet 52 is positioned at the reference position P1. With the solder transfer unit 5 positioned at the reference position P1, the scraper 51 descends in the Z direction to a predetermined position above the detection unit 8a. In this state, the detection unit 8a performs a second marker detection operation to detect the marker portion 52M at the reference position P1, after the recovery operation by the solder transfer sheet 52 and before the supply operation.

[0067] In the second recognition process a6 following the second marker detection process a5, the positional displacement recognition unit 301 recognizes the second marker positional displacement amount ML2 as the amount of positional displacement of the marker portion 52M to be detected on the solder transfer sheet 52 with respect to the reference position P1, based on the detection result in the second marker detection operation of the detection unit 8a. In this case, it is possible to estimate the amount of displacement of the circumferential movement in the retrieval operation of the solder transfer sheet 52 with respect to the reference movement amount SL, based on the second marker positional displacement amount ML2. This makes it possible to estimate the amount of retrieval positional displacement of the solder paste SP retrieved on the solder transfer sheet 52 with respect to the appropriate retrieval position in accordance with the retrieval operation of the solder transfer sheet 52.

[0068] In the second positional misalignment correction process a7 following the second recognition process a6, the control unit 302 corrects the position of the marker portion 52M relative to the reference position P1 by moving the solder transfer sheet 52 in a circular motion according to the second marker positional misalignment amount ML2, after the retrieval operation by the solder transfer sheet 52 and before the supply operation. This allows the position of the marker portion 52M on the solder transfer sheet 52 relative to the reference position P1 to be corrected after the retrieval operation by the solder transfer sheet 52 and before the supply operation. In this case, the position of the solder paste SP collected on the solder transfer sheet 52 can be corrected according to the amount of misalignment of the circular motion of the solder transfer sheet 52 in the retrieval operation relative to the reference motion amount SL, which corresponds to the second marker positional misalignment amount ML2. This allows the solder paste SP collected on the solder transfer sheet 52 to be positioned at the appropriate retrieval position according to the retrieval operation of the solder transfer sheet 52. When the solder paste SP collected on the solder transfer sheet 52 is in the correct collection position, the solder transfer sheet 52 rotates around the solder transfer sheet 52 by a reference movement amount SL during the supply operation, thereby enabling the solder paste SP on the solder transfer sheet 52 to be supplied to the correct supply position on the mask 4. When the position of the marker portion 52M on the solder transfer sheet 52 relative to the reference position P1 is corrected, the control unit 302 raises the scraper 51.

[0069] After the second misalignment correction process a7, when the control unit 302 executes the solder supply process a8, the solder transfer unit 5 moves in the X direction to reach a predetermined supply position P3. With the solder transfer unit 5 positioned at the supply position P3, the scraper 51 descends in the Z direction so that the solder transfer sheet 52 contacts the mask 4. In this state, the solder transfer sheet 52 performs a supply operation to supply the collected solder paste SP onto the mask 4 by circulating in the second direction D2 by a predetermined reference movement amount SL. When the supply operation by the solder transfer sheet 52 is performed, the scraper 51 moves in the second X direction DD2, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51 as it circulates in the second direction D2. This makes it possible to supply the solder paste SP on the solder transfer sheet 52 onto the mask 4 without distorting the shape of the solder roll, which is a mass of solder paste SP.

[0070] After the solder supply process a8, the control unit 302 executes a solder width measurement process s1 to control the solder width measuring unit 6b and a printing process s2 to control the squeegee unit 6. When the control unit 302 executes the solder width measurement process s1, the solder width measuring unit 6b measures the solder roll width SW, which indicates the width of the solder roll, a mass of solder paste SP on the mask 4. When the control unit 302 executes the printing process s2, the squeegee 6a of the squeegee unit 6 moves the solder paste SP on the mask 4, thereby printing the solder paste SP onto the substrate P through the printing opening of the mask 4.

[0071] (Second Embodiment) The printing apparatus 1 according to the second embodiment will be described with reference to Figures 8 to 11. The printing apparatus 1 of the second embodiment has the same basic configuration as the printing apparatus 1 of the first embodiment, except that the configuration of the detection unit 8a in the detection unit 8 and the object to be detected on the solder transfer sheet 52 by the detection unit 8a are different.

[0072] In the printing apparatus 1 of the second embodiment, the detection unit 8a is a laser sensor having a light-emitting unit 8a1 that emits laser light and a light-receiving unit 8a2 that receives the laser light. The detection target of the detection unit 8a is the recovered solder roll SPR, which is a mass of solder paste SP recovered on the solder transfer sheet 52 by the recovery operation of the solder transfer sheet 52. The detection unit 8a performs a recovered solder detection operation at a reference position P1 after the recovery operation by the solder transfer sheet 52 and before the supply operation, to detect the recovered solder roll SPR on the solder transfer sheet 52. When the detection unit 8a performs the recovered solder detection operation, the scraper 51 moves in the X direction while the circumferential movement of the solder transfer sheet 52 is stopped. As the scraper 51 moves, while the recovered solder roll SPR on the solder transfer sheet 52 passes the reference position P1, the light received by the light receiving unit 8a2 from the light emitting unit 8a1 is blocked by the recovered solder roll SPR. That is, from the time the tip of the recovered solder roll SPR on the solder transfer sheet 52 passes the reference position P1 until the rear end of the recovered solder roll SPR passes the reference position P1, the light received by the light receiving unit 8a2 from the light emitting unit 8a1 is blocked by the recovered solder roll SPR. The detection unit 8a detects the recovered solder roll SPR on the solder transfer sheet 52 at the reference position P1 based on the switching between ON and OFF of the light receiving unit 8a2 receiving the laser light.

[0073] In the printing apparatus 1 of the second embodiment, the control unit 30 performs solder recovery processing b1, recovered solder detection processing b2, recognition processing b3, positional misalignment correction processing b4, and solder supply processing b5 during the solder transfer process. In the control unit 30, recognition processing b3 is performed by the positional misalignment recognition unit 301, and the other processes are performed by the control unit 302.

[0074] When the control unit 302 executes the solder recovery process b1, the solder transfer unit 5 moves in the X direction to reach a predetermined recovery position P2. With the solder transfer unit 5 positioned at the recovery position P2, the scraper 51 descends in the Z direction so that the solder transfer sheet 52 contacts the mask 4. In this state, the solder transfer sheet 52 performs a recovery operation to recover solder paste SP from the mask 4 by moving in a circumferential manner in the first direction D1 by a predetermined reference movement amount SL. When the recovery operation by the solder transfer sheet 52 is performed, the scraper 51 moves in the first X direction DD1, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51 as it moves in a circumferential manner in the first direction D1. When the recovery operation of the solder transfer sheet 52 is completed, the control unit 302 raises the scraper 51.

[0075] After the solder recovery process b1, when the control unit 302 executes the recovered solder detection process b2, the solder transfer unit 5 moves in the X direction to reach the reference position P1. With the solder transfer unit 5 positioned at the reference position P1, the scraper 51 descends in the Z direction to a predetermined detection position. In this state, the scraper 51 moves in the X direction. The detection unit 8a performs a recovered solder detection operation at the reference position P1 to detect the recovered solder roll SPR on the solder transfer sheet 52 after the recovery operation by the solder transfer sheet 52 and before the supply operation. The detection unit 8a detects the recovered solder roll SPR on the solder transfer sheet 52 at the reference position P1 based on the switching of the laser light reception by the light receiving unit 8a2 between ON and OFF.

[0076] In the recognition process b3 following the recovered solder detection process b2, the positional displacement recognition unit 301 recognizes the recovered solder positional displacement amount SLL as the amount of positional displacement of the recovered solder roll SPR to be detected on the solder transfer sheet 52 relative to the reference position P1, based on the detection result in the recovered solder detection operation of the detection unit 8a. The positional displacement recognition unit 301 calculates the difference between the ideal distance L0, which represents the ideal distance from the tip of the scraper 51 to the rear end of the recovered solder roll SPR, and the actual detected distance L1 based on the detection result of the detection unit 8a, and recognizes this difference as the recovered solder positional displacement amount SLL. In this case, based on the recovered solder positional displacement amount SLL, it is possible to estimate the amount of displacement of the circumferential movement of the solder transfer sheet 52 relative to the reference movement amount SL during the recovery operation, and it is also possible to estimate the amount of recovery positional displacement of the solder paste SP recovered on the solder transfer sheet 52 relative to the appropriate recovery position according to the recovery operation.

[0077] In the positional misalignment correction process b4 following the recognition process b3, the control unit 302 corrects the position of the recovered solder roll SPR relative to the reference position P1 by moving the solder transfer sheet 52 in a circular motion according to the recovered solder misalignment amount SLL, after the recovery operation by the solder transfer sheet 52 and before the supply operation. This makes it possible to correct the position of the recovered solder roll SPR relative to the reference position P1 on the solder transfer sheet 52 after the recovery operation by the solder transfer sheet 52 and before the supply operation. In this case, the position of the recovered solder paste SP on the solder transfer sheet 52 can be corrected according to the recovered solder misalignment amount SLL. This makes it possible to position the recovered solder paste SP on the solder transfer sheet 52 at the appropriate recovery position according to the recovery operation of the solder transfer sheet 52. When the solder paste SP collected on the solder transfer sheet 52 is in the correct collection position, the solder transfer sheet 52 rotates around the solder transfer sheet 52 by a reference movement amount SL during the supply operation, thereby enabling the solder paste SP on the solder transfer sheet 52 to be supplied to the correct supply position on the mask 4. When the position of the collected solder roll SPR on the solder transfer sheet 52 relative to the reference position P1 is corrected, the control unit 302 raises the scraper 51.

[0078] After the misalignment correction process b4, when the control unit 302 executes the solder supply process b5, the solder transfer unit 5 moves in the X direction to reach a predetermined supply position P3. With the solder transfer unit 5 positioned at the supply position P3, the scraper 51 descends in the Z direction so that the solder transfer sheet 52 contacts the mask 4. In this state, the solder transfer sheet 52 performs a supply operation by circling in the second direction D2 with a predetermined reference movement amount SL, thereby supplying the collected solder paste SP onto the mask 4. When the supply operation by the solder transfer sheet 52 is performed, the scraper 51 moves in the second X direction DD2, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51 as it circulates in the second direction D2.

[0079] After the solder supply process b5, the control unit 302 performs a solder width measurement process s1 to control the solder width measuring unit 6b and a printing process s2 to control the squeegee unit 6. When the control unit 302 performs the solder width measurement process s1, the solder width measuring unit 6b measures the solder roll width SW, which indicates the width of the solder roll, a mass of solder paste SP on the mask 4. When the control unit 302 performs the printing process s2, the squeegee 6a of the squeegee unit 6 moves the solder paste SP on the mask 4, thereby printing the solder paste SP onto the substrate P through the printing opening of the mask 4.

[0080] (Third embodiment) The printing apparatus 1 according to the third embodiment will be described with reference to Figures 12 and 13. The printing apparatus 1 of the third embodiment has the same basic configuration as the printing apparatus 1 of the first embodiment, except that the object to be detected on the solder transfer sheet 52 by the detection unit 8a is different.

[0081] In the printing apparatus 1 of the third embodiment, the detection target of the detection unit 8a is the solder trace SPT, which indicates the trace of solder paste SP remaining on the solder transfer sheet 52 after the supply operation by the solder transfer sheet 52. After the supply operation by the solder transfer sheet 52, the detection unit 8a performs a solder trace detection operation to detect the solder trace SPT on the solder transfer sheet 52 at a reference position P1. The detection unit 8a detects the solder trace SPT on the solder transfer sheet 52 when the rotational movement of the solder transfer sheet 52 has stopped.

[0082] In the printing apparatus 1 of the third embodiment, the control unit 30 performs solder recovery processing c1, solder supply processing c2, solder trace detection processing c3, ​​recognition processing c4, solder width measurement position adjustment processing c5, and squeegee position adjustment processing c6 during the solder transfer process. In the control unit 30, the recognition processing c4 is performed by the position misalignment recognition unit 301, and the other processes are performed by the control unit 302.

[0083] When the control unit 302 executes the solder recovery process c1, the solder transfer unit 5 moves in the X direction to reach a predetermined recovery position P2. With the solder transfer unit 5 positioned at the recovery position P2, the scraper 51 descends in the Z direction so that the solder transfer sheet 52 contacts the mask 4. In this state, the solder transfer sheet 52 performs a recovery operation to recover solder paste SP from the mask 4 by moving in a circumferential manner in a first direction D1 by a predetermined reference movement amount SL. When the recovery operation by the solder transfer sheet 52 is performed, the scraper 51 moves in a first X direction DD1, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51 as it moves in a circumferential manner in the first direction D1. When the recovery operation of the solder transfer sheet 52 is completed, the control unit 302 raises the scraper 51.

[0084] After the solder recovery process c1, when the control unit 302 executes the solder supply process c2, the solder transfer unit 5 moves in the X direction to reach a predetermined supply position P3. With the solder transfer unit 5 positioned at the supply position P3, the scraper 51 descends in the Z direction so that the solder transfer sheet 52 contacts the mask 4. In this state, the solder transfer sheet 52 performs a supply operation by circulating in the second direction D2 with a predetermined reference movement amount SL, thereby supplying the recovered solder paste SP onto the mask 4. When the supply operation by the solder transfer sheet 52 is performed, the scraper 51 moves in the second X direction DD2, which is opposite to the direction in which the upper part of the solder transfer sheet 52 moves relative to the scraper 51 as it circulates in the second direction D2.

[0085] After the solder supply process c2, when the control unit 302 executes the solder trace detection process c3, the solder transfer unit 5 moves in the X direction to reach the reference position P1. With the solder transfer unit 5 positioned at the reference position P1, the scraper 51 descends in the Z direction to a predetermined detection position. In this state, the detection unit 8a performs a solder trace detection operation at the reference position P1 to detect the solder trace SPT on the solder transfer sheet 52 after the supply operation by the solder transfer sheet 52.

[0086] In the recognition process c4 following the solder trace detection process c3, the positional displacement recognition unit 301 recognizes the solder trace positional displacement amount STL as the amount of positional displacement of the solder trace SPT to be detected on the solder transfer sheet 52 relative to the reference position P1, based on the detection result in the solder trace detection operation of the detection unit 8a. In this case, based on the solder trace positional displacement amount STL, it is possible to estimate the amount of displacement of the circumferential movement of the solder transfer sheet 52 relative to the reference movement amount SL during the supply operation, and it is also possible to estimate the amount of supply positional displacement of the solder paste SP supplied from the solder transfer sheet 52 onto the mask 4 relative to the appropriate supply position according to the supply operation.

[0087] In the solder width measurement position adjustment process c5 following the recognition process c4, the control unit 302 adjusts the measurement position of the solder width measurement unit 6b based on the solder trace position displacement amount STL after the supply operation by the solder transfer sheet 52. By adjusting the measurement position of the solder width measurement unit 6b based on the solder trace position displacement amount STL, the solder width measurement unit 6b can accurately measure the width of the solder roll, which is a mass of solder paste SP on the mask 4. Furthermore, in the squeegee position adjustment process c6 following the recognition process c4, the control unit 302 adjusts the starting position of the squeegee 6a when it moves the solder paste SP on the mask 4 based on the solder trace position displacement amount STL after the supply operation by the solder transfer sheet 52. By adjusting the starting position of the squeegee 6a based on the solder trace position displacement amount STL, it is possible to suppress the deformation of the solder roll, which is a mass of solder paste SP on the mask 4, by the squeegee 6a when the squeegee 6a is positioned at the starting position. [Explanation of symbols]

[0088] 1 Printing device 4 Masks 5. Solder Transfer Unit 52 Solder Transfer Sheet 6 Squeegee Units 6a Squeegee 6b Solder width measuring section 8 detection units 8a Detection unit 30 Control Units 301 Position deviation recognition unit 302 Control Unit

Claims

1. A printing apparatus for printing solder paste onto a circuit board, A mask having a printing opening and being replaceably positioned above the substrate, A squeegee that moves the solder paste on the mask to print the solder paste onto the substrate through the printing opening, A solder transfer sheet, which is a sheet extending in the longitudinal direction, is provided so as to be able to move circumferentially in a first direction along the longitudinal direction and in a second direction opposite to the first direction, and performs a collection operation in which the sheet collects the solder paste from the mask by moving circumferentially in the first direction by a predetermined reference movement amount, and a supply operation in which the sheet collects the solder paste and supplies it onto the mask by moving circumferentially in the second direction by the reference movement amount, A detection unit that detects the object to be detected on the solder transfer sheet at a predetermined reference position, A printing apparatus comprising: a positional displacement recognition unit that recognizes the amount of positional displacement of the detected object on the solder transfer sheet relative to the reference position based on the detection result of the detection unit.

2. The printing apparatus according to claim 1, wherein the detection unit detects the object to be detected when the circumferential movement of the solder transfer sheet is stopped.

3. The printing apparatus according to claim 1, wherein the detection unit includes at least one camera that detects the target based on an image, and a laser sensor that detects the target based on laser light.

4. The object to be detected is a plurality of markers consisting of a plurality of marks or holes provided at regular intervals in the longitudinal direction on the solder transfer sheet. The detection unit performs a first mark detection operation to detect the mark at the reference position before the recovery operation by the solder transfer sheet, and a second mark detection operation to detect the mark at the reference position after the recovery operation by the solder transfer sheet and before the supply operation. The printing apparatus according to claim 1, wherein the position misalignment recognition unit performs a first recognition process that recognizes the first marker position misalignment amount as the position misalignment amount based on the detection result of the first marker detection operation of the detection unit, and a second recognition process that recognizes the second marker position misalignment amount as the position misalignment amount based on the detection result of the second marker detection operation of the detection unit.

5. The reference displacement is set according to the solder roll width, which indicates the width of the solder roll, which is a mass of solder paste on the mask. The printing apparatus according to claim 4, wherein, in the plurality of marking portions provided on the solder transfer sheet, the distance between adjacent marking portions is set to a value obtained by adding a predetermined margin to the width of the solder roll.

6. The printing apparatus according to claim 4, wherein, in the plurality of marking portions provided on the solder transfer sheet, the distance between adjacent marking portions is set to be the same as the reference movement amount.

7. The system further includes a control unit that controls the circumferential movement of the solder transfer sheet, The control unit, Prior to the recovery operation using the solder transfer sheet, a first positional misalignment correction process is performed to correct the position of the marker portion relative to the reference position by moving the solder transfer sheet in a circular motion according to the amount of misalignment of the first marker. The printing apparatus according to claim 4, wherein, after the recovery operation using the solder transfer sheet and before the supply operation, a second positional misalignment correction process is performed to correct the position of the mark portion with respect to the reference position by moving the solder transfer sheet in a circular motion according to the amount of misalignment of the second mark.

8. The object to be detected is a recovered solder roll, which is a mass of solder paste recovered onto the solder transfer sheet by the recovery operation. The detection unit performs a recovered solder detection operation to detect the recovered solder roll at the reference position after the recovery operation by the solder transfer sheet and before the supply operation. The printing apparatus according to claim 1, wherein the positional misalignment recognition unit recognizes the amount of recovered solder misalignment as the amount of positional misalignment based on the detection result in the recovered solder detection operation of the detection unit.

9. The system further includes a control unit that controls the circumferential movement of the solder transfer sheet, The printing apparatus according to claim 8, wherein the control unit performs a positional misalignment correction process to correct the position of the recovered solder roll relative to the reference position by moving the solder transfer sheet in a circular motion according to the amount of misalignment of the recovered solder, after the recovery operation by the solder transfer sheet and before the supply operation.

10. The object to be detected is a solder trace that shows the trace of the solder paste remaining on the solder transfer sheet after the supply operation by the solder transfer sheet. The detection unit performs a solder trace detection operation to detect the solder trace at the reference position after the supply operation by the solder transfer sheet. The printing apparatus according to claim 1, wherein the positional misalignment recognition unit recognizes the amount of solder trace misalignment as the amount of positional misalignment based on the detection result in the solder trace detection operation of the detection unit.

11. A solder width measuring unit for measuring the width of the solder roll on the mask, which is a mass of solder paste on the mask, The system further comprises a control unit that controls the solder width measuring unit and the squeegee, The printing apparatus according to claim 10, wherein the control unit adjusts the measurement position of the solder width measuring unit based on the amount of solder trace displacement after the supply operation by the solder transfer sheet, and also adjusts the starting position of the movement when the squeegee moves the solder paste on the mask.

Images