JP5476139B2 - Printing apparatus and printing method - Google Patents

Description

  The present invention relates to a technique for providing a plurality of substrate conveying means for conveying a substrate and printing a paste such as a solder paste or a conductive paste on the substrate conveyed by each substrate conveying means.

  In order to enhance the work efficiency of paste printing on a substrate, a printing apparatus provided with a plurality of substrate conveying means for conveying a substrate has been conventionally proposed. For example, the screen printing apparatus described in Patent Literature 1 includes two screen printing machines that include a substrate carry-in unit, a print execution unit, a substrate carry-out unit, and a substrate moving stage, and perform paste printing. In each screen printing machine, the substrate carried in by the substrate carry-in section is clamped by the substrate moving stage and aligned at a predetermined position directly below the mask plate, and then paste printing is performed on the substrate. As described above, since the alignment and paste printing can be independently performed on the two substrates, the apparatus is excellent in terms of printing accuracy and cycle time.

Japanese Patent Laying-Open No. 2009-70867 (FIG. 6)

  In the screen printing apparatus described in Patent Document 1, two screen printing machines are provided on one base, and two screen printing apparatuses that operate independently as a whole are arranged in parallel. Will also be compact. However, since it is necessary to provide two mechanisms (substrate loading unit, printing execution unit, substrate unloading unit, and substrate moving stage) that constitute the screen printing machine, the apparatus configuration is complicated and the cost is high. was there.

  The present invention has been made in view of the above problems, and provides a printing apparatus and a printing method capable of printing paste on a plurality of substrates with a simple configuration with high accuracy and at low cost. For the purpose.

  In order to achieve the above object, a printing apparatus according to the present invention includes a first substrate transport unit that transports a first substrate having a first print pattern in a first direction, and a second substrate having a second print pattern. A second stage carrying means for carrying in the first direction; a printing stage for holding a first substrate carried by the first board carrying means; a second substrate carried by the second substrate carrying means; A mask holding means for holding a mask having a first opening pattern corresponding to the printing pattern and a second opening pattern corresponding to the second printing pattern above the first substrate and the second substrate held on the printing stage; Printing means for printing the paste on the first printed pattern of the first substrate through the first opening pattern and printing the paste on the second printed pattern of the second substrate through the second opening pattern; substrate When the relative difference between the positional deviation of the first printed pattern and the positional deviation of the second printed pattern with respect to the second substrate is within the first allowable range, the printing means applies the paste to the first substrate and the second substrate. And a control unit that prints the paste on the second substrate after the printing unit prints the paste on the first substrate when the first allowable range is exceeded. Yes.

  In order to achieve the above object, the printing method according to the present invention transports a first substrate having a first print pattern to a printing stage by a first substrate transport means, and a second substrate having a second print pattern. A second substrate transporting means for transporting the first substrate and the second substrate on the printing stage, and a first opening pattern corresponding to the first printed pattern and a second printed pattern A mask having a second opening pattern to be disposed above the printing stage, a positional deviation of the first printed pattern with respect to the first substrate, and a positional deviation of the second printed pattern with respect to the second substrate The step of obtaining the difference, and when the relative difference is within the first allowable range, printing of the paste on the first print pattern via the first opening pattern and the second print via the second opening pattern While the paste is printed on the turn in a lump, when the first allowable range is exceeded, the paste is printed on the first printing pattern via the first opening pattern and then the second printing pattern via the second opening pattern. And a step of printing a paste.

  In the invention thus configured (printing apparatus and printing method), the first substrate transport means and the second substrate transport means are provided so that the substrates can be transported independently of each other, and so-called dual lane structure is adopted. Has been. Then, the substrate is carried into the printing stage by each substrate conveying means, and the paste is printed. Here, when the relative difference (relative accuracy difference) between the positional deviation of the first printed pattern with respect to the first substrate and the positional deviation of the second printed pattern with respect to the second substrate is within the first allowable range, the plurality of substrates. The paste is batch printed. That is, the first substrate and the second substrate are held with respect to the printing stage, and the printing of the paste on the first printed pattern of the first substrate and the printing of the paste on the second printed pattern of the second substrate are collectively performed. Are executed at the same time. In this way, batch printing can be performed on a plurality of substrates in one printing stage, and high-precision and efficient printing can be performed with a simple configuration compared to the apparatus described in Patent Document 1. . When the relative difference exceeds the first allowable range, paste printing on the first printed pattern of the first substrate and paste printing on the second printed pattern of the second substrate are sequentially performed, High-precision printing is guaranteed.

  Here, if a displacement information image indicating the displacement is attached to each substrate, the displacement of the pattern to be printed with respect to the substrate can be obtained from the displacement information image for each substrate. Therefore, after the displacement information image attached to each of the first substrate and the second substrate is imaged by the first imaging means, and the positional displacement is obtained for each substrate based on the imaging result, the relative difference (relative accuracy difference) is obtained. You may comprise as follows.

  In addition, misalignment may occur with respect to the first substrate and the second substrate held on the printing stage, and batch printing becomes difficult when the relative difference between them (relative misalignment amount) increases. Accordingly, there is further provided a second imaging means for imaging the mark attached to each of the first substrate and the second substrate held on the printing stage, and the relative difference between the positional deviation of the first substrate and the positional deviation of the second substrate. Exceeds the second allowable range, even if the relative accuracy difference is within the first allowable range, the paste is printed on the first substrate by the printing means, and then the paste is printed on the second substrate. Is desirable. By configuring in this way, high-precision printing is ensured.

  The printing stage includes a movable portion, a first conveyance portion that conveys the first substrate carried on the movable portion by the first substrate conveyance means in the first direction, and a second substrate conveyance means that is carried on the movable portion. A second transport unit that transports the second substrate in the first direction, and a positioning mechanism unit that drives the movable unit to position the first substrate and the second substrate with respect to the mask. Good. By adopting such a configuration, the structure is simplified compared to the case where a positioning mechanism is provided for each transport unit as in the device described in Patent Document 1, and the cost and size of the device are reduced. It becomes possible.

  Further, while the first substrate is positioned and fixed to the first transfer jig and the second substrate is positioned and fixed to the second transfer jig, the first transfer jig and the second transfer jig are held by the printing means while the first transfer jig is held. The paste may be printed on the first substrate and the second substrate. When each substrate is positioned and fixed by the transport jig in this way, even if the outer shape and dimensions vary from one substrate to another, the substrate can be transported or held with the precision of the transport jig, and high accuracy can be achieved. Printing is possible.

  As described above, the first substrate and the second substrate are held and fixed with respect to one printing stage. When the relative difference between the positional deviation of the first printed pattern relative to the first substrate and the positional deviation of the second printed pattern relative to the second substrate is within the first allowable range, batch printing is performed on these substrates. Is executed. Therefore, it is possible to perform printing with high accuracy and efficiency with a simple configuration as compared with the apparatus described in Patent Document 1.

It is a top view which shows one Embodiment of the printing apparatus concerning this invention. It is a side view which shows schematic structure of the printing apparatus in the state which installed the mask. It is a perspective view which shows typically the positional relationship of a board | substrate, a mask, and a squeegee. FIG. 2 is a block diagram illustrating a main electrical configuration of the printing apparatus. 2 is a flowchart illustrating an operation of the printing apparatus in FIG. 1. It is a flowchart which shows operation | movement of a 1st alternate printing process. It is a flowchart which shows the operation | movement of a 2nd alternate printing process. It is a flowchart which shows operation | movement of a batch printing process. It is a figure which shows the 1st alternate printing process typically. It is a figure which shows the 2nd alternate printing process typically. It is a figure which shows the 2nd alternate printing process typically. It is a figure which shows a batch printing process typically. It is a schematic diagram which shows the relationship between the manufacture aspect of the board | substrate used as printing object, and the position shift aspect of a to-be-printed pattern. It is a perspective view which shows the conveyance jig used with another embodiment of the printing apparatus concerning this invention.

  FIG. 1 is a plan view showing an embodiment of a printing apparatus according to the present invention, and shows a schematic configuration of the printing apparatus in a state where no mask is installed. FIG. 2 is a side view showing a schematic configuration of the printing apparatus with a mask installed. FIG. 3 is a perspective view schematically showing the positional relationship between the substrate, the mask, and the squeegee. FIG. 4 is a block diagram showing the main electrical configuration of the printing apparatus. In this printing apparatus, a printing stage 20 is provided on the base 10. The printing stage 20 has a pair of transport units 21A and 21A that transport the substrate 1A from the lower right side to the lower left side in FIG. Then, the transport unit 21A is operated in accordance with a drive command from the printing stage control unit 43 of the control unit 40 to transport the substrate 1A from the right side to the left side in the X-axis direction (first direction), and the substrate 1A is moved to the front side in the Y-axis direction. Positioning is stopped by a stopper (not shown) at a fixed position (position of the lower center side substrate 1A in FIG. 1). In the printing stage 20, a pair of transport units 21B and 21B are arranged side by side on the rear side (−Y side) of the transport unit 21A in the Y-axis direction. When the transport unit 21B operates in response to a drive command from the printing stage control unit 43 of the control unit 40, the substrate 1B is transported from the upper right side to the upper left side in FIG. Positioning is stopped by a stopper (not shown) at the side fixing position (the position of the upper central substrate 1B in FIG. 1). The substrates 1A and 1B are fixed and held by the holding mechanism unit (not shown) of the printing stage 20 at each fixing position.

  In the present embodiment, the carry-in conveyors 31A and 31B are provided on the right side surface portion of the apparatus, and the carry-out conveyors 32A and 32B are provided on the left side surface portion of the apparatus. Among these conveyors, the carry-in conveyors 31A and 31A are provided for carrying in the X-axis direction while supporting the unprocessed substrate 1A on which the paste is to be printed, and carrying it into the printing stage 20, and a carry-out conveyor 32A. Is provided to transport the printed substrate 1A in the X-axis direction while supporting it. In the Y-axis direction, a pair of carry-in conveyors 31B and 31B are arranged in parallel on the rear side (−Y side) of the conveyor 31A, and a pair of carry-out conveyors 32B are arranged in parallel on the rear side (−Y side) of the conveyor 32A. Has been. Then, the carry-in conveyor 31B conveys in the X-axis direction while supporting the unprocessed substrate 1B and carries it into the printing stage 20, and the carry-out conveyor 32B conveys in the X-axis direction while supporting the printed substrate 1B. It is configured. Thus, in the present embodiment, the carry-in conveyors 31A and 31B function as the “first substrate transport unit” and the “second substrate transport unit” of the present invention, respectively.

  When the printing stage 20 moves to a conveyance position described later, the conveyance unit 21A on the printing stage 20 is positioned between the carry-in conveyor 31A and the carry-out conveyor 32A, and the conveyance unit 21B is located between the carry-in conveyor 31B and the carry-out conveyor 32B. Positioned. When the carry-in conveyor 31A is driven in a state where the print stage 20 is positioned at the transport position in this way, the substrate 1A before the printing process is sent to the transport unit 21A provided in the print stage 20. Further, when the carry-in conveyor 31 </ b> B is driven in the same state, the substrate 1 </ b> B before the printing process is sent to the transport unit 21 </ b> B provided in the printing stage 20. As described above, in the present embodiment, a so-called dual lane structure having two transport paths is employed on the right side (substrate carry-in side) in the X-axis direction with respect to the printing stage 20, and the front side and the rear side in the Y-axis direction are employed. Thus, the substrate can be carried into the printing stage 20 independently. In the present embodiment, the dual lane structure is adopted on the left side (substrate unloading side) in the X-axis direction with respect to the printing stage 20 as described later, and the substrates are independently provided on the front side and the rear side in the Y-axis direction. The printing stage 20 can be carried out.

  The printing stage 20 has a movable plate 22 having a rectangular shape in plan view. The movable plate 22 is moved two-dimensionally in the horizontal plane (XY plane) by the drive unit group 23, and is also in the vertical direction Z. And is rotated in the R direction with respect to the vertical axis. Further, on the movable plate 22, the above-described transport units 21 </ b> A and 21 </ b> B, a stopper, a holding mechanism unit, and a backup unit 24 are provided. As described above, the drive unit group 23 is a positioning mechanism unit that moves and positions the movable plate 22 in the X-axis direction, the Y-axis direction, the Z-axis direction, and the R-axis direction. A general mechanism is used. The same applies to the stopper and the holding mechanism. Therefore, the description about the concrete structure of these drive unit groups (positioning mechanism part) 23, a stopper, and a holding mechanism part is abbreviate | omitted.

  The backup unit 24 is disposed on the movable plate 22. The backup unit 24 includes a backup plate 241, a plurality of backup pins 242, and an elevating mechanism (not shown) that is disposed between the backup plate 241 and the movable plate 22 and drives the backup plate 241 to move up and down. The backup pins 242 are erected upward from the backup plate 241, and the lower surfaces of the substrates 1 </ b> A and 1 </ b> B can be supported from below by the tip portions of the backup pins 242. Then, by operating the lifting mechanism by the printing stage controller 43, the backup plate 241 is moved upward to position the substrates 1A, 1B from the transporting portions 21A, 21B. On the other hand, when the backup plate 241 is lowered, the substrates 1A and 1B are returned from the backup pin 242 to the conveying units 21A and 21B, and the backup pin 242 is further retracted below the substrates 1A and 1B.

  In the printing stage 20, the movable plate 22 is moved in the X axis direction, the Y axis direction, and the R axis direction (direction rotating around the vertical axis) by the printing stage control unit 43 of the control unit 40 as described above. The substrates 1A and 1B held by the holding mechanism while being backed up by the backup pins 242 are moved to the printing position and positioned with respect to the mask 51. This mask 51 has a thin plate-like stencil attached to the lower surface side of a mask frame (mask frame) 52. The mask 51 has an opening pattern 53a (FIG. 3) corresponding to the printed pattern on the substrate 1A and the printed pattern on the substrate 1B. A corresponding opening pattern 53b (FIG. 3) is provided in advance. The mask 51 thus configured is fixedly arranged above the printing stage 20 by holding the mask frame 52 by the mask clamp unit 50. Then, the solder paste supplied onto the mask 51 from a solder supply unit (not shown) is spread on the mask 51 by reciprocating the squeegee 71 of the squeegee unit 70 in the Y-axis direction. At this time, solder paste is printed on the upper surfaces of the substrates 1A and 1B through the opening patterns 53A and 53B provided in the mask 51, respectively. Therefore, by controlling the moving range of the squeegee 71 as described later, it is possible to print the solder paste on the substrates 1A and 1B at once or alternately print the substrates 1A and 1B. As described above, in this embodiment, the mask clamp unit 50 functions as the “mask holding unit” of the present invention, and the squeegee unit 70 functions as the “printing unit” of the present invention.

  When the paste printing on the substrates 1A and 1B is completed in this way, in the printing stage 20, the drive unit group 23 positions the movable plate 22 at the transport position in accordance with the drive command from the print stage control unit 43. At this transfer position, the transfer unit 21A is positioned between the carry-in conveyor 31A and the carry-out conveyor 32A and at the same height as the conveyors 31A and 32A, and the transfer unit 21B is positioned between the carry-in conveyor 31B and the carry-out conveyor 32B, and It is positioned at the same height as the conveyors 31B and 32B. When the carry-out conveyor 32A is driven in this positioning state and the transport unit 21A is driven, the transport unit 21A transports the processed substrate 1A that has undergone the printing process to the carry-out conveyor 32A as described later. In the same state, when the carry-out conveyor 32B is driven and the transport unit 21B is driven, the transport unit 21B transports the processed substrate 1B subjected to the printing process to the carry-out conveyor 32B as described later. As described above, the substrates 1A and 1B can be carried out from the printing stage 20 simultaneously or at different timings.

  In this embodiment, as shown in FIGS. 3 and 4, a fiducial camera 60 is provided between the printing stage 20 and the mask 51 so as to be movable in the XY directions by a fiducial camera driving mechanism 63. The fiducial camera 60 includes a substrate camera unit 61 that captures fiducial marks FM1 and FM2 attached to the upper surfaces of the substrates 1A and 1B held on the printing stage 20, and a fiducial camera attached to the lower surface of the mask 51. And a mask camera unit 62 for imaging a dual mark (not shown). Then, the fiducial camera drive mechanism 63 moves the fiducial camera 60 in the X-axis direction and the Y-axis direction in response to a drive command from the camera control unit 44 of the control unit 40. During this movement, the substrate camera unit 61 images the fiducial marks FM1 and FM2 of the substrates 1A and 1B held on the printing stage 20, and the mask camera unit 62 images the fiducial mark of the mask 51, Those image data are output to the camera control unit 44. Thus, in the present embodiment, the board camera unit 61 corresponds to the “second imaging unit” of the present invention.

  The camera control unit 44 performs various image processing on the image data and outputs the processed image data to the arithmetic processing unit 41. The arithmetic processing unit 41 includes a CPU, a memory, and the like. Based on image information from the camera control unit 44, the fixed positions of the substrates 1A and 1B, their relative positional shift amounts, the fixed position of the mask 51, and the like. And a printing process to be described later is executed.

  Further, in this embodiment, the front standby position camera 64A is disposed above the carry-in conveyor 31A, and the unprocessed substrate 1A that is stopped by waiting by a stopper (not shown) provided on the carry-in conveyor 31A. Can be imaged. On the carry-in conveyor 31B side, similarly to the carry-in conveyor 31A side, a rear standby position camera 64B is arranged above the carry-in conveyor 31B so that the unprocessed substrate 1B on standby can be imaged. These standby position cameras 64 </ b> A and 64 </ b> B capture an image MI (hereinafter referred to as “deviation information image”) MI indicating the deviation information of the board, and output the captured deviation information image MI to the camera control unit 44. As described above, the standby position cameras 64A and 64B correspond to the “first imaging unit” of the present invention. However, a configuration may be adopted in which the displacement information image MI of the substrates 1A and 1B is captured by one camera. . The “substrate misalignment information” means information indicating how much the pattern to be printed formed on the upper surface of the substrate, that is, the pattern on which the solder paste is to be printed, deviates from a preset pattern position. In this embodiment, each substrate is measured in advance as follows, and the measurement result is imaged with a two-dimensional code such as a QR code (registered trademark of DENSO WAVE INCORPORATED).

The printed pattern on the substrates 1A and 1B is created based on CAD (Computer Aided Design) data, but the position of the printed pattern formed on the substrate may deviate from the position of the printed pattern on the CAD data. . Therefore, in this embodiment, the formation position of the printed pattern on the substrate 1A is measured, and the overall positional deviation of the printed pattern with respect to the outer shape of the substrate 1A is the X displacement amount XA and Y displacement amount YA in the XY plane. The rotation amount θA is obtained. In order to improve the measurement accuracy of the positional deviation, the deviation amounts are measured at a plurality of points over the entire substrate 1A, and the average values thereof are set as the X deviation amount XA, the Y deviation amount YA, and the rotation amount θA, respectively. Is desirable. For the substrate 1B as well, as in the case of the substrate 1A, the overall positional deviation amount (XB, YB, θB) of the pattern to be printed with respect to the outer shape of the substrate 1B is obtained. Accordingly, it is possible to accurately read the displacement information of each of the substrates 1A and 1B by capturing the displacement information image MI indicating such a displacement amount and analyzing the displacement information image MI. That is, in the present embodiment, the deviation information image MI captured by the standby position cameras 64A and 64B is output to the camera control unit 44, and after appropriate image processing is added by the camera control unit 44, it is output to the arithmetic processing unit 41. Is done. Then, the arithmetic processing unit 41 uses the positional shift amounts (XA, YA, θA) of the substrate 1A and the positional shift amounts (XB, YB, θB) of the substrate 1B to obtain relative shift information dX, dY, dθ is expressed by the following equation: dX = XA−XB
dY = YA-YB
dθ = θA−θB
Calculate according to In addition, since the result calculated in this manner accurately indicates the relative shift of the pattern to be printed formed on the substrates 1A and 1B, it can be used as a criterion for determining whether or not to perform batch printing as will be described later.

Here, when there is a local area where printing accuracy is particularly required in the pattern to be printed, the position of the pattern in the local area for each of the substrates 1A and 1B instead of the overall positional deviation of the pattern to be printed. The deviation amounts (X2A, Y2A, θ2A), (X2B, Y2B, θ2B) may be obtained and used as the positional deviation amounts (XA, YA, θA), (XB, YB, θB) of the substrates 1A, 1B. In this case as well, it is desirable to measure each shift amount at a plurality of points in the local area and set the average values thereof as X shift amounts X2A, X2B, Y shift amounts Y2A, Y2B, and rotation amounts θ2A, θ2B, respectively. Further, the positional deviation amounts (XA, YA, θA), (XB, YB, θB) of the respective substrates 1A, 1B may be combined by combining the overall positional deviation amount of the pattern to be printed and the positional deviation amount of the local area. . For example, when the total positional deviation amount of the printed pattern of each substrate 1A, 1B is (X1A, Y1A, θ1A), (X1B, Y1B, θ1B), the positional deviation amount (XA, YA) of each substrate 1A, 1B. , ΘA), (XB, YB, θB) is expressed by the following formula: XA = X1A + X2A
YA = Y1A + Y2A
θA = θ1A + θ2A
XB = X1B + X2B
YB = Y1B + Y2B
θB = θ1B + θ2B
Can be set to

  As shown in FIG. 4, the printing apparatus configured as described above is provided with a control unit 40 that controls the entire printing apparatus. The control unit 40 includes an arithmetic processing unit 41, a program storage unit 42, a printing stage control unit 43, and a camera control unit 44. The arithmetic processing unit 41 repeatedly performs printing processes (first alternating printing process, second alternating printing process, and batch printing process) by controlling each part of the printing apparatus according to a printing program stored in advance in the program storage unit 42. . Further, the printing stage control unit 43 controls actuators such as various motors and air cylinders incorporated in the printing stage 20 to carry in and carry out the substrates 1A and 1B by the conveying units 21A and 21B, and to move the substrates 1A and 1B to the mask 51. Perform positioning and so on. Further, as described above, the camera control unit 44 performs predetermined image processing on the image data picked up by the standby position cameras 64A and 64B, the substrate camera 61, and the mask camera unit 62 to acquire deviation information, Position information about 1A and 1B is obtained, and position information about the mask 51 is obtained. Reference numeral 45 in the figure is a display / operation unit for displaying a printing program, an error message, and the like, and for inputting information such as various data and commands to the control unit 40 by an operator.

  Next, the operation of the printing apparatus configured as described above will be described with reference to FIGS. 5 to 8 are flowcharts showing the operation of the printing apparatus of FIG. FIG. 9 is a diagram schematically showing the first alternating printing process, FIGS. 10 and 11 are diagrams schematically showing the second alternating printing process, and FIG. 12 schematically shows the batch printing process. FIG. In this printing apparatus, two carry-in conveyors 31A and 31B are provided, and the front end portions (the left end portion in FIG. 1) of unprocessed substrates 1A and 1B before printing abut each other by a stopper (not shown). Waiting. Then, the control unit 40 controls each part of the printing apparatus according to the printing program, and carries in, prints and carries out the unprocessed substrate as follows.

  While waiting for the unprocessed substrates 1A and 1B, the front standby position camera 64A captures the misalignment information image MI attached to the unprocessed substrate 1A that is waiting by the carry-in conveyor 31A, and the rear standby position camera 64B is the carry-in conveyor. The deviation information image MI attached to the unprocessed substrate 1B on standby at 31B is imaged (step S1). Based on the deviation information images MI of the substrates 1A and 1B thus imaged, the arithmetic processing unit 41 acquires the deviation information of the substrates 1A and 1B, respectively, and calculates the relative accuracy difference between the substrates 1A and 1B (step S2). More specifically, the arithmetic processing unit 41 obtains the relative deviation information dX (= XA−XB), dY (= YA−YB), dθ (= θA−θB) of the substrates 1A and 1B as described above. The deviation information dX, dY, dθ is stored in the memory as a relative accuracy difference. When the relative accuracy difference is large, when the substrates 1A and 1B are held on the printing stage 20 as will be described later, the print patterns on the substrates 1A and 1B are greatly shifted from each other. Therefore, for example, when the printing pattern attached to the substrate 1A is positioned with respect to the opening pattern 53a of the mask 51, the printing pattern of the substrate 1B is largely shifted from the opening pattern 53b of the mask 51. Therefore, in the present embodiment, prior to the printing of the solder paste on the printing stage 20, it is determined whether or not the relative accuracy differences dX, dY, dθ are equal to or less than the allowable values X0, Y0, θ0 (step S3). ). If the determination result is “NO”, that is, if the relative accuracy differences dX, dY, dθ exceed the allowable range, a first alternating printing process (step S4) described later is executed to solder the substrates 1A, 1B. The paste is printed alternately.

  On the other hand, if it is determined in step S3 that the relative accuracy differences dX, dY, dθ are within the allowable range, the substrates 1A, 1B are transferred from the carry-in conveyors 31A, 31B to the transfer units 21A, 21B of the printing stage 20, respectively. . At this time, the printing stage 20 is positioned at the transport position, and the stoppers provided in the transport portions 21A and 21B are positioned so as to protrude upward from the transport path of the substrate. The substrates 1A and 1B conveyed by the conveyance units 21A and 21B are locked by stoppers and stopped at the fixed position, and then fixed by the holding mechanism unit of the printing stage 20 (step S5).

In the next step S6, the fiducial camera 60 is moved in the X-axis direction and the Y-axis direction by the fiducial camera drive mechanism 63, and the substrate camera unit 61 moves the fiducials of the substrates 1A and 1B during this movement. The marks FM1 and FM2 are imaged. Based on the fiducial marks FM1 and FM2 thus imaged, the arithmetic processing unit 41 obtains a fixed position of the substrates 1A and 1B, and a positional deviation amount (fixed positional deviation amount) from a preset fixed position in the horizontal plane. And the relative positional deviation amount (relative positional deviation amount) is calculated (step S7). For example, when the fixed position deviation amounts XSA, YSA, θSA of the substrate 1A and the fixed position deviation amounts XSB, YSB, θSB of the substrate 1B are obtained from the fiducial marks FM1, FM2, the following formula is given: dXS = XSA−XSB
dYS = YSA-YSB
dθS = θSA−θSB
The relative positional deviation amount is calculated according to

  Here, when the substrates 1 </ b> A and 1 </ b> B held and fixed to the printing stage 20 are greatly displaced from each other, for example, if the substrate 1 </ b> A is positioned with respect to the mask 51, the substrate 1 </ b> B is greatly displaced from the mask 51. Therefore, in this embodiment, prior to the printing of the solder paste on the printing stage 20, the relative positional deviation amounts dXS (= XSA-XSB), dYS (= YSA-YSB), and dθS (= θSA-θSB) are allowed. It is determined whether or not the values are less than or equal to XS0, YS0, and θS0 (step S8). If the determination result is “NO”, that is, if the relative positional deviation exceeds the allowable value, a second alternating printing process (step S9) described later is executed to mount the substrates 1A and 1B on the printing stage 20. The solder paste is printed on the substrates 1A and 1B alternately.

  On the other hand, if it is determined in step S8 that the relative positional deviation amount is equal to or less than the allowable value, the solder paste is collectively printed on the substrates 1A and 1B held and fixed on the printing stage 20 (step S10: Batch printing process).

  Next, each of the “first alternating printing process”, “second alternating printing process”, and “batch printing process” will be described in detail.

<First alternate printing process>
FIG. 6 is a flowchart showing the operation of the first alternate printing process. In this first alternate printing process, as shown in FIGS. 6 and 9, the stopper of the carry-in conveyor 31A among the stoppers provided on the carry-in conveyors 31A and 31B is retracted below the conveyance path of the substrate 1A by the carry-in conveyor 31A. Thus, only the substrate 1A is transferred to the transfer unit 21A of the printing stage 20. In the printing stage 20, after the substrate 1A conveyed by the conveying unit 21A is locked by the stopper of the conveying unit 21A and stopped at the fixed position, as shown in the lower part of FIG. It is fixed by the holding mechanism (step S401).

  The fiducial camera 60 is moved in the X-axis direction and the Y-axis direction by the fiducial camera drive mechanism 63, and the substrate camera unit 61 images the fiducial marks FM1 and FM2 on the substrate 1A during this movement. At the same time, the fiducial mark (not shown) of the mask 51 is imaged (step S402). Based on the fiducial marks FM1 and FM2 thus imaged, the arithmetic processing unit 41 calculates the relative positional relationship between the substrate 1A and the mask 51 in the horizontal plane. Based on the calculation result, the printing stage 20 is moved in the X axis direction, the Y axis direction, and the R axis direction so that the fiducial marks on the lower surface of the mask 51 coincide with the fiducial marks FM1 and FM2 of the substrate 1A. The position of the substrate 1A with respect to the mask 51 in the horizontal plane is corrected. Simultaneously with the start of positioning of the substrate 1A with respect to the mask 51, the movable plate 22 is raised to raise the substrate 1A toward the printing position, and the positioning of the substrate 1A with respect to the mask 51 is completed. (Step S403). Thereafter, paste P such as cream solder is supplied to the upper surface of the mask 51, and the movement of the squeegee 71 to the rear side in the Y-axis direction is started while controlling the printing load and moving speed (step S404). 9B, when the squeegee 71 passes through the opening pattern 53a of the mask 51 and the paste P is printed on the printed pattern on the upper surface of the substrate 1A (step S405), the squeegee 71 is moved. Stop (step S406). At this time, the paste P on the upper surface of the squeegee 71 and the mask 51 is located between the opening patterns 53a and 53b.

  When the paste printing on the substrate 1A is completed in this way, the movable plate 22 is moved downward by the printing stage control unit 43, and returned to the original position by moving the movable plate 22 for positioning the substrate 1A with respect to the mask 51. Return the movable plate 22 to. Then, the printing stage 20 is moved to the transport position (step S407). Thereafter, as shown in the lower part of FIG. 9C, after releasing the holding of the substrate 1A by the holding mechanism unit, the backup plate 241 is lowered to transfer the substrate 1A from the backup pin 242 to the transport unit 21A. Further, the backup pin 242 is retracted below the substrate 1A. The printed substrate 1A returned to the transport unit 21A in this way is transported to the carry-out conveyor 32A by the transport unit 21A (step S408).

  When the substrate 1A is unloaded from the printing stage 20, the substrate 1B is loaded into the printing stage 20 and pasted in the same manner as the substrate 1A, and then unloaded to the unloading conveyor 32B (steps S409 to S416). The carry-in, paste printing, and carry-out processes for the substrate 1B are the same as the series of processes for the substrate 1A, except that the substrate transfer lanes are different.

  As described above, according to the first alternate printing process (step S4), even if the relative accuracy differences dX, dY, dθ exceed the allowable range and the printed patterns on the substrates 1A, 1B are greatly shifted from each other, The paste P can be printed on the printing pattern with high accuracy for 1A and 1B.

<Second alternate printing process>
FIG. 7 is a flowchart showing the operation of the second alternate printing process. At the time of starting the second alternate printing process (step S9), as shown in FIG. 10A, the two substrates 1A and 1B are fixed at the fixed positions on the printing stage 20, respectively. As described above, a large positional deviation occurs between the substrates 1A and 1B. Therefore, each part of the apparatus is controlled by the operation flow shown in FIG. First, after the fixing of the substrate 1B by the holding mechanism unit is released (step S901), the fiducial mark on the lower surface of the mask 51 and the fiducial mark FM1 of the substrate 1A acquired when the steps S6 and S7 are already executed, The printing stage 20 is moved in the X-axis direction, the Y-axis direction, and the R-axis direction based on the positional information regarding FM2, so that the fiducial marks on the lower surface of the mask 51 coincide with the fiducial marks FM1 and FM2 on the substrate 1A. The position of the substrate 1A with respect to the mask 51 in the horizontal plane is corrected. Simultaneously with the start of positioning of the substrate 1A with respect to the mask 51, the movable plate 22 is raised to raise the substrate 1A toward the printing position, and the positioning of the substrate 1A with respect to the mask 51 is completed. (Step S902). Thereafter, paste printing on the substrate 1A and unloading of the substrate 1A are performed in the same manner as in steps S404 to S408 in the first alternate printing process (steps S903 to S907: FIGS. 10B and 10C).

  When the substrate 1A is unloaded from the printing stage 20, the unprocessed substrate 1B remaining on the printing stage 20 is fixed again by the holding mechanism unit of the printing stage 20 as shown in FIG. 11A (step S908). ). As described above, since the substrate 1B is re-fixed, the position of the substrate 1B may move at that time. Therefore, in the present embodiment, the fiducial camera 60 is moved in the X-axis direction and the Y-axis direction by the fiducial camera drive mechanism 63, and the substrate camera unit 61 moves the fiducial mark on the substrate 1B during this movement. FM1 and FM2 are imaged (step S909). Based on the fiducial marks FM1 and FM2 thus imaged, the arithmetic processing unit 41 calculates the relative positional relationship between the substrate 1B and the mask 51 in the horizontal plane. Based on the calculation result, the printing stage 20 is moved in the X axis direction, the Y axis direction, and the R axis direction so that the fiducial marks on the lower surface of the mask 51 coincide with the fiducial marks FM1 and FM2 of the substrate 1B. The position of the substrate 1B with respect to the mask 51 in the horizontal plane is corrected. Simultaneously with the start of positioning of the substrate 1B with respect to the mask 51, the movable plate 22 is raised to raise the substrate 1B toward the printing position, and the positioning of the substrate 1B with respect to the mask 51 is completed. (Step S910). Thereafter, the squeegee 71 stopped between the opening patterns 53a and 53b is driven again, that is, the squeegee 71 starts to move rearward in the Y-axis direction (step S911). Then, as shown in FIG. 11B, when the squeegee 71 passes through the opening pattern 53b of the mask 51 and the paste P is printed on the printed pattern on the upper surface of the substrate 1B (step S912), the squeegee 71 is moved. Stop (step S913). At this time, the paste P on the upper surface of the squeegee 71 and the mask 51 is located behind the opening pattern 53b in the Y-axis direction.

  When the paste printing on the substrate 1B is completed in this way, it is carried out to the carry-out conveyor 32B in the same manner as the substrate 1A (steps S914 and S915).

  As described above, according to the second alternate printing process (step S9), even if the substrates 1A and 1B are mounted on the printing stage 20 even though they are mounted on the two substrates 1A and 1B, each substrate is shifted greatly. The paste P can be printed on the printing pattern with high accuracy for 1A and 1B.

<Batch printing process>
FIG. 8 is a flowchart showing the operation of the batch printing process. At the time of starting the batch printing process (step S10), the relative positional deviation amount is equal to or less than the allowable value, and the two substrates 1A and 1B are fixed to the printing stage 20 without a large positional deviation. Further, the relative accuracy differences dX, dY, dθ are equal to or less than the allowable values X0, Y0, θ0, respectively. Therefore, the substrates 1A and 1B can be easily and accurately aligned with respect to the mask 51. More specifically, based on various pieces of information that have already been calculated (position information on the fiducial marks on the lower surface of the mask 51 and fiducial marks FM1 and FM2 on the substrates 1A and 1B, relative positional deviation amount, deviation information, etc.). The printing stage 20 is moved in the X-axis direction, the Y-axis direction, and the R-axis direction so that the fiducial marks on the lower surface of the mask 51 coincide with the fiducial marks FM1 and FM2 of the substrates 1A and 1B. The positions of the substrates 1A and 1B with respect to the mask 51 are corrected.

  Simultaneously with the start of positioning of the substrates 1A and 1B with respect to the mask 51, the movable plate 22 is raised to raise the substrates 1A and 1B toward the printing position, and the positioning of the substrate 1A with respect to the mask 51 is performed, that is, the opening pattern 53a. , 53b are brought into close contact with the lower surface of the mask 51 in a state where they are positioned so as to overlap the printed patterns of the substrates 1A and 1B, respectively (step S101).

  Subsequently, the paste P is supplied to the upper surface of the mask 51, and the movement of the squeegee 71 to the rear side in the Y-axis direction is started while controlling the printing load and the moving speed (step S102). Then, as shown in FIG. 12B, when the squeegee 71 passes through the opening patterns 53a and 53b of the mask 51 and the paste P is printed on the printed pattern on the top surfaces of the substrates 1A and 1B (step S103), The movement of 71 is stopped (step S104). At this time, the paste P on the upper surface of the squeegee 71 and the mask 51 is located behind the opening pattern 53b in the Y-axis direction.

  When paste printing on the substrates 1A and 1B is performed at once, the movable plate 22 is moved downward by the printing stage control unit 43 and returned by the amount moved for positioning the substrates 1A and 1B with respect to the mask 51. Return to the original position. Then, the printing stage 20 is moved to the transport position (step S105). Thereafter, as shown in the lower part of FIG. 12C, after releasing the holding of the substrates 1A and 1B by the holding mechanism unit, the backup plate 241 is lowered to transfer the substrate 1A from the backup pin 242 to the transfer units 21A and 21B. 1B are transferred, and the backup pins 242 are retracted below the substrates 1A and 1B. In this way, the printed substrate 1A returned to the transport unit 21A is transported to the carry-out conveyor 32A by the transport unit 21A, and the printed substrate 1B returned to the transport unit 21B is transported by the transport unit 21B. It is conveyed to the carry-out conveyor 32B (step S106).

As described above, according to the present embodiment, two transport lanes different from each other for one printing stage 20 (that is, the transport paths of the conveyors 31A, 21A, and 32A and the transport paths of the conveyors 31B, 21B, and 32B). Is provided, so that the two substrates 1A and 1B can be fixed to the printing stage 20. And two conditions (1) and condition (2)
Condition (1): The relative difference (relative accuracy difference) between the positional deviation of the printed pattern with respect to the substrate 1A and the positional deviation of the printed pattern with respect to the substrate 1B is within an allowable range.
Condition (2): The relative positional deviation amount (relative positional deviation amount) of the substrates 1A and 1B fixed to the printing stage 20 is equal to or less than an allowable value.
When both are satisfied, paste printing on the substrates 1A and 1B is performed collectively by one squeegee movement. Therefore, it is possible to perform printing with high accuracy and efficiency with a simple configuration as compared with the apparatus described in Patent Document 1.

  In the present embodiment, the first alternating printing process (step S4) is executed when the condition (1) is not satisfied, and the second alternating printing is performed when the condition (2) is not satisfied. Since the process (step S9) is executed to perform paste printing on the printed pattern on the substrate 1A and paste printing on the printed pattern on the substrate 1B in order, the above conditions (1) and (2) Even if the case is not satisfied, the paste can be printed on the substrate without reducing the printing accuracy.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, the displacement information is created by measuring the positional displacement amount of the pattern to be printed formed on the substrate. However, the displacement information is not limited to this, and for example, as follows. Deviation information may be created and the condition (1) may be determined (step S3).

When manufacturing the substrates 1A and 1B, as in the case where a plurality of semiconductor chips are formed from a single wafer, for example, as shown in FIG. Are often cut out from the large substrate 100 into the small substrates 1A and 1B. When the substrates 1A and 1B are formed in this way, the following tendency is often recognized in the positional deviation of the printed pattern depending on the position of each small substrate 1A and 1B at the time of substrate formation. For example, when a printed pattern is formed on the rear side (upper side in the figure) from the front side (lower side in the figure) of the large board 100, the distortion amount is small in the small board located on the near side of the large board 100. It is relatively small. On the other hand, the strain amount gradually increases depending on the forming direction, and the strain direction tends to be different in the left-right direction in FIG. Therefore, the amount of misalignment depending on the position of each substrate 1A, 1B at the time of substrate formation is as follows:
A: The amount of distortion is a small rank,
BR: The amount of strain is medium, and the rank is offset in the back right direction with respect to the forming direction.
BC: The amount of distortion is medium, the rank is offset in the depth direction of the formation direction,
BL: The amount of strain is medium, the rank is offset in the back left direction with respect to the formation direction,
CR: A rank that has a large amount of distortion and is offset in the back right direction with respect to the forming direction.
CL: The amount of distortion is large, and the rank is offset to the left back direction with respect to the forming direction.
Can be divided into classes. Therefore, when the substrates 1A and 1B are created, the rank information may be reflected in the displacement information image MI as “substrate displacement information”. In this case, it is possible to accurately read the ranks of the substrates 1A and 1B by capturing the displacement information image MI and analyzing the displacement information image MI, and the rank combination (rank of the substrate 1A, substrate 1B rank), it is possible to accurately obtain the relative displacement of the pattern to be printed formed on the substrates 1A and 1B. For example, in the case of combinations (A, A), (BC, BC), (BR, BR), (CR, CR), etc., the positional deviation of the printed pattern with respect to the substrate 1A and the positional deviation of the printed pattern with respect to the substrate 1B It is possible to determine that the relative difference (relative accuracy difference) is small and within an allowable range. On the other hand, in the case of a combination (CR, CL) or the like, it can be determined that the relative accuracy difference is large and exceeds the allowable range.

  In the above embodiment, the batch printing process is executed when both the condition (1) and the condition (2) are satisfied. However, there is little variation in the shape and dimensions of the board outline due to individual differences between the boards 1A and 1B. If the positional deviation between the substrates 1A and 1B at the fixed position is small, the batch printing process may be executed immediately when only the condition (1) is satisfied.

  On the other hand, due to variations in the shape and dimensions of the outer shape of the substrate due to individual differences between the substrates 1A and 1B, sufficient repetition accuracy cannot be obtained by fixing the substrate with the holding mechanism, making it difficult to perform batch printing stably. There is a case. Therefore, for example, as shown in FIG. 14, a transfer jig 90 corresponding to the substrates 1A and 1B may be used. The accuracy of the shape and dimensions of the outer shape of the conveying jig 90 is guaranteed. In addition, a concave portion 91 that is the same or slightly larger than the substrates 1A and 1B is formed in the central portion of the upper surface of the conveying jig 90, and the substrates 1A and 1B are configured to fit completely into the concave portion 91. . Further, positioning pins 92a and 92b are erected on the inner bottom surface of the recess 91 at positions corresponding to the positioning holes 10a and 10b provided at predetermined positions of the substrates 1A and 1B, respectively. Note that the height of the pins 92a and 92b from the inner bottom surface of the recess 91 is equal to or less than the thickness of the substrates 1A and 1B. For this reason, when the positioning pins 92a and 92b are respectively inserted into the positioning holes 10a and 10b of the substrates 1A and 1B and the substrates 1A and 1B are inserted into the recesses 91, the substrates 1A and 1B are accurately positioned with respect to the conveying jig 90. It is integrated while being done. Therefore, when the substrates 1A and 1B are transported to the printing stage 20 together with the transport jig 90 and fixed by the holding mechanism section, the substrate 1A and 1B can be repeated with sufficient repeatability even if there are variations in the external shape and dimensions. 1A and 1B can be fixed to the printing stage 20. As a result, paste printing on the substrates 1A and 1B can be performed stably.

  In the above embodiment, the present invention is applied to a printing apparatus in which one squeegee 71 moves to execute paste printing. However, printing in which two or more squeegees are moved to execute paste printing is performed. The present invention can also be applied to an apparatus.

  In the above embodiment, the present invention is applied to a dual lane printing apparatus having two transport lanes. However, the present invention is also applied to a printing apparatus having three or more transport lanes. It can be applied, and the same effect as the above embodiment can be obtained. That is, in the printing apparatus provided with three or more transport lanes as described above, high-precision and efficient printing can be performed by performing batch printing in all the transport lanes as in the above-described embodiment. Further, the present invention is not limited to batch printing in all the transport lanes, and is configured to execute batch printing in some of the plurality of transport lanes (two or more transport lanes). May be.

DESCRIPTION OF SYMBOLS 1A, 1B ... Board | substrate 20 ... Printing stage 21A, 21B ... Conveyance part 23 ... Drive unit group (positioning mechanism part)
40. Control unit (control means)
41. Arithmetic processing part (control means)
53a, 53b ... opening pattern 50 ... mask clamp unit (mask holding means)
61 ... Substrate camera section (second imaging means)
64A, 64B ... standby position camera (first imaging means)
70 ... Squeegee unit (printing means)
FM1, FM2 ... Fiducial mark MI ... Displacement information image P ... Paste

Claims (6)

First substrate transport means for transporting a first substrate having a first printed pattern in a first direction;
A second substrate transfer means for transferring a second substrate having a second printed pattern in the first direction;
A printing stage for holding the first substrate carried in by the first substrate carrying means and the second substrate carried in by the second substrate carrying means;
A mask having a first opening pattern corresponding to the first printing pattern and a second opening pattern corresponding to the second printing pattern is formed on the first substrate and the second substrate held on the printing stage. Mask holding means for holding above;
Printing that prints the paste on the first printed pattern of the first substrate through the first opening pattern and prints the paste on the second printed pattern of the second substrate through the second opening pattern Means,
When the relative difference between the positional deviation of the first printed pattern with respect to the first substrate and the positional deviation of the second printed pattern with respect to the second substrate is within a first allowable range, the printing means causes the first While the paste is printed on the substrate and the second substrate at once, the paste on the second substrate is printed after the paste is printed on the first substrate by the printing means when the first allowable range is exceeded. And a control means for performing printing. A first imaging means for imaging a displacement information image indicating the positional displacement, which is attached to each of the first substrate and the second substrate;
The printing apparatus according to claim 1, wherein the control unit obtains the relative difference based on the positional deviation between the first substrate and the second substrate obtained from the deviation information image imaged by the first imaging unit. A second imaging means for imaging a mark attached to each of the first substrate and the second substrate held on the printing stage;
The control means is when the relative difference between the positional deviation of the first printed pattern with respect to the first substrate and the positional deviation of the second printed pattern with respect to the second substrate is within a first allowable range. However, the positional deviation of the first substrate and the positional deviation of the second substrate are obtained from the positional information of the mark imaged by the second imaging means, and the positional deviation of the first substrate and the position of the second substrate are obtained. 3. The printing according to claim 1, wherein when the relative difference from the deviation exceeds a second allowable range, the paste is printed on the second substrate after the printing means performs printing of the paste on the first substrate. apparatus.   The printing stage includes a movable portion, a first transport portion that transports the first substrate carried by the first substrate transport means on the movable portion in the first direction, and the second transport portion on the movable portion. Positioning for positioning the first substrate and the second substrate with respect to the mask by driving the movable portion and a second transport unit for transporting the second substrate carried in by the substrate transport means in the first direction. The printing apparatus according to claim 1, further comprising a mechanism unit. The first substrate is positioned and fixed to the first transport jig, and the second substrate is positioned and fixed to the second transport jig,
The first substrate transport means transports the first transport jig to the printing stage,
The second substrate transport means transports the second transport jig to the printing stage,
The control unit prints the paste on the first substrate and the second substrate by the printing unit while holding the first transport jig and the second transport jig. A printing apparatus according to claim 1. The first substrate having the first print pattern is transferred to the printing stage by the first substrate transfer means, and the second substrate having the second print pattern is transferred to the print stage by the second substrate transfer means to the printing stage. Holding the first substrate and the second substrate;
Disposing a mask having a first opening pattern corresponding to the first printing pattern and a second opening pattern corresponding to the second printing pattern above the printing stage;
Obtaining a relative difference between a positional deviation of the first printed pattern with respect to the first substrate and a positional deviation of the second printed pattern with respect to the second substrate;
When the relative difference is within the first allowable range, printing of the paste on the first printing pattern via the first opening pattern and printing of the paste on the second printing pattern via the second opening pattern are performed. On the other hand, when the first allowable range is exceeded, the paste is printed on the first printed pattern via the first opening pattern and then pasted on the second printed pattern via the second opening pattern. And a printing method.

Images