JP2013146942A - Screen printer, and screen printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printer and a screen printing method which can easily and accurately determine positional shift correction values at any time without interrupting a screen printing operation.SOLUTION: While a correction mark Q is located at a second height H2 lower than a first height H1 which is a height of a lower face of a mask 13, the correction mark Q is imaged from the upper side by a downward imaging camera 14a, so as to calculate coordinates (X2, Y2) of the correction mark Q at the position of the second height H2. While the correction mark Q is located at the first height H1, the correction mark Q is imaged from the lower side by an upward imaging camera 14b, so as to calculate coordinates (X1, Y1) of the correction mark Q at the position of the first height H1. Differences (X2-X1, Y2-Y1) between the coordinates of the correction mark Q at the position of the second height H2 and the coordinates of the correction mark Q at the position of the first height H1 are calculated as positional shift correction values (δx, δy).

Description

  The present invention relates to a screen printing machine and a screen printing method for printing a paste such as solder on a substrate by sliding a squeegee on a mask in contact with the substrate.

  A screen printing machine is a device that prints a paste such as solder on an electrode on a substrate held by a substrate holding unit, and a pattern hole corresponding to the electrode on the substrate is aligned vertically with the electrode and the pattern hole. Then, the substrate holding part is raised and the substrate is brought into contact with the lower surface of the mask, and the squeegee is slid on the mask supplied with the paste to slide the squeegee to the substrate electrode through the mask pattern hole. The paste is transferred.

  In such a screen printing machine, when performing vertical alignment between the mask and the substrate before the substrate is brought into contact with the mask, the lower imaging unit with the imaging field facing downward and the upper imaging unit with the imaging field facing upward The position of the substrate side mark calculated by imaging the substrate side mark provided on the substrate by the lower imaging unit of the camera unit and the mask provided on the mask by the upper imaging unit of the camera unit are used. Based on the position of the mask-side mark calculated by imaging the side mark, the substrate is aligned with the mask so that the substrate-side mark and the mask-side mark coincide vertically (for example, Patent Documents). 1).

  Here, when the optical axis of the lower imaging unit and the optical axis of the upper imaging unit are not deviated or inclined from the optical axes on the corresponding design data, the board-side mark and the upper imaging unit viewed through the lower imaging unit The positional relationship with the mask side mark seen through is equal to the actual positional relationship, and after aligning the substrate so that these marks are aligned vertically, the substrate is raised and brought into contact with the mask. The pattern hole of the mask and the pattern hole of the mask coincide with each other without positional deviation, but at least one of the optical axis of the lower imaging unit and the optical axis of the upper imaging unit is shifted or inclined from the optical axis in the design data In this case, the positional relationship between the substrate-side mark viewed through the lower imaging unit and the mask-side mark viewed through the upper imaging unit is not equal to the actual positional relationship, and the two marks are aligned vertically. It does not match the substrate electrode and the mask pattern holes of even by increasing the substrate is brought into contact with the mask after having aligned the substrate so that, so that the positional displacement occurs. A similar positional shift can also occur when the moving direction of the substrate when the aligned substrate is raised with respect to the mask is inclined from the vertical direction.

  For this reason, conventionally, before performing screen printing, the substrate is aligned so that the substrate side mark viewed through the lower imaging unit and the mask side mark viewed through the upper imaging unit are aligned vertically, and then the substrate When the screen printing test print is actually performed by raising and contacting the mask, and the resulting positional displacement occurs between the electrode on the substrate and the pattern hole in the mask, the amount of positional displacement is misaligned. Obtained as a calibration value, the mask and the substrate are aligned in the vertical direction using this positional deviation calibration value.

JP 2008-36918 A

  However, the above-described conventional method for obtaining the positional deviation calibration value requires a lot of work because trial printing must actually be performed, and if the paste to be trial printed spreads on the substrate, an accurate position is obtained. There was a problem that it was difficult to calculate the deviation calibration value. In addition, since the screen printing operation itself needs to be temporarily interrupted, there is a problem that the substrate productivity is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a screen printing machine and a screen printing method capable of obtaining a misregistration calibration value at any time without interrupting screen printing work simply and accurately.

  The screen printing machine according to claim 1, wherein a substrate holding unit that holds a substrate having an electrode on an upper surface thereof, a mask provided with a pattern hole corresponding to the electrode of the substrate, and a downward imaging with an imaging field of view facing downward Part, an upper imaging unit with the imaging field of view upward, a position of the substrate side mark calculated by imaging the substrate side mark provided on the substrate by the lower imaging unit, and a mask provided on the mask by the upper imaging unit A substrate holding unit that raises and lowers the substrate holding unit based on the position of the mask side mark calculated by imaging the side mark and then raises the substrate holding unit to contact the substrate with the lower surface of the mask A screen printing machine having a movement control unit and a squeegee that slides on a mask in contact with the substrate and prints paste on the electrode of the substrate through the pattern hole of the mask. With A calibration member positioned at a height of the upper surface of the substrate held by the substrate holding unit, and a calibration mark capable of imaging from above by the lower imaging unit and imaging from below by the upper imaging unit, and the calibration The calibration mark is positioned in the lower imaging unit in a state where the vertical position of the substrate holding unit is adjusted so that the mark for use is positioned at a second height lower than the first height which is the height of the lower surface of the mask. By adjusting the position of the substrate holding portion in the vertical direction so that the calibration mark is located at the first height and the coordinates of the position at the second height of the calibration mark calculated by imaging from above are calculated. In this state, the calibration mark is imaged from below by the upper imaging unit, and the difference in the horizontal plane between the coordinates of the position at the first height of the calibration mark is calculated. Position displacement calibration value calculation calculated as a value The substrate holding unit movement control unit performs vertical alignment between the mask and the substrate using the positional deviation calibration value calculated by the positional deviation calibration value calculation unit, and then the substrate holding unit with respect to the mask. The substrate is brought into contact with the lower surface of the mask by raising.

  The screen printing method according to claim 2, wherein a substrate holding portion that holds a substrate having an electrode on an upper surface, a mask provided with a pattern hole corresponding to the electrode on the substrate, and a downward imaging with an imaging field of view facing downward Part, an upper imaging unit with the imaging field of view upward, a position of the substrate side mark calculated by imaging the substrate side mark provided on the substrate by the lower imaging unit, and a mask provided on the mask by the upper imaging unit A substrate holding unit that raises and lowers the substrate holding unit based on the position of the mask side mark calculated by imaging the side mark and then raises the substrate holding unit to contact the substrate with the lower surface of the mask A movement control unit, a squeegee that slides on the mask in contact with the substrate and prints paste on the electrode of the substrate through the pattern hole of the mask, and is attached to the substrate holding unit and is held by the substrate holding unit. A screen printing method using a screen printing machine having a jig member on which a calibration mark capable of being imaged from above by the lower imaging unit and imaged from below by the upper imaging unit is located at the height of the upper surface of the substrate. The calibration mark is adjusted in the vertical direction so that the calibration mark is positioned at a second height lower than the first height which is the height of the lower surface of the mask. And calculating the coordinates of the position of the calibration mark at the second height by the lower imaging unit from above, and the substrate holding unit so that the calibration mark is positioned at the first height. The calibration mark is imaged from below by the upper imaging unit with the vertical position adjusted, and the position coordinates at the first height of the calibration mark are calculated, and the calculated calibration mark The position at the second height of the mark And calculating the difference in the horizontal plane direction between the coordinates of the calibration mark and the coordinates of the position at the first height of the calibration mark as a positional deviation calibration value, and using the calculated positional deviation calibration value, the mask and the substrate The substrate holding part is raised with respect to the mask and the substrate is brought into contact with the lower surface of the mask, and the squeegee is slid on the mask in contact with the substrate to form the pattern hole of the mask. And a step of printing a paste on the electrode of the substrate through the substrate.

  In the present invention, a calibration mark that is located at the height of the upper surface of the substrate when the substrate is held by the substrate holding unit and can be imaged from above by the lower imaging unit and from below by the upper imaging unit is held by the substrate. The calibration mark is calculated by imaging the calibration mark located at the second height lower than the first height, which is the height of the lower surface of the mask, from above by the lower imaging unit. The first coordinate of the calibration mark calculated by imaging the coordinate of the position at the height of 2 and the calibration mark located at the first height which is the height of the lower surface of the mask from below by the upper imaging unit. The difference in the horizontal plane direction from the coordinates of the position at the height is calculated as the position deviation calibration value, so it can be easily and accurately positioned at any time without interrupting the screen printing operation. Obtaining the deviation calibration value It can be.

The side view of the screen printer in one embodiment of the present invention The partial top view of the screen printer in one embodiment of this invention The flowchart which shows the execution procedure of the calculation operation | work of the position offset calibration value by the screen printer in one embodiment of this invention The perspective view of the principal part of the screen printer in one embodiment of this invention The perspective view of the principal part of the screen printer in one embodiment of this invention (A) (b) (c) The figure explaining the procedure which calculates | requires the position shift calibration value of the screen printer in one embodiment of this invention. The figure explaining the procedure which calculates | requires the position shift calibration value of the screen printer in one embodiment of this invention. (A) (b) The figure explaining the procedure which calculates | requires the position shift calibration value of the screen printer in one embodiment of this invention. The flowchart which shows the execution procedure of the screen printing operation by the screen printer in one embodiment of this invention (A) (b) The figure explaining the procedure which performs screen printing with the screen printer in one embodiment of this invention (A) (b) The partial cross section side view which shows the other form of the jig | tool member with which the screen printer in one embodiment of this invention is provided.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, a screen printing machine 1 carries in and positions a substrate 2 having a large number of electrodes 2a on the upper surface, and screen-prints a paste Pt such as solder on each of the electrodes 2a of the substrate 2. A device for performing work, a substrate holding unit moving mechanism 11 provided on the base 10, a substrate holding unit 12 moved by the substrate holding unit moving mechanism 11, a mask 13 provided above the substrate holding unit 12, A camera unit 14 provided movably below the mask 13, a squeegee unit 15 provided movably above the mask 13, and a control device 16 that controls the operation of each part of the screen printer 1.

  In this screen printing machine 1, the mask 13 is made of a metal plate having four sides supported by a rectangular mask frame 13w, and a large number of pattern holes 13h corresponding to the electrodes 2a of the substrate 2 are provided at the center thereof. The mask 13 is held in a horizontal posture with a mask frame 13w supported from below by a mask holder (not shown) installed above the substrate holding unit 12, and the lower surface of the mask 13 from the base 10 has a first height. It is located in the horizontal plane W1 (FIG. 1) of the height H1.

  In FIG. 1, a substrate holding unit 12 functions as a substrate holding unit for holding a substrate 2, and is attached to a base portion 12a and a base portion 12a that can be moved up and down with respect to a base 10, and within a horizontal plane. Of the substrate 2 transported to a predetermined work position by the conveyor 12b, the conveyor 12b transporting the substrate 2 in the X-axis direction (the direction perpendicular to the paper surface in FIG. 1, the left-right direction of the paper surface in FIG. 2). A lower receiving member 12c that supports the lower surface from below, a substrate lifting cylinder 12d that lifts and lowers the lower receiving member 12c, and a substrate 2 pushed up by the substrate lifting cylinder 12d in a horizontal plane direction orthogonal to the transport direction (X-axis direction) of the substrate 2 It has a pair of clamp members 12e that are clamped and held from the Y axis direction. The control device 16 controls the transport operation of the substrate 2 by the conveyor 12b, the lift operation of the substrate 2 by the substrate lift cylinder 12d, and the clamp operation of the substrate 2 by the pair of clamp members 12e. In addition, the board | substrate 2 of the state clamped by the clamp member 12e leaves | separates from the upper surface of the conveyor 12b, and an upper surface becomes the same height as the upper surface of the clamp member 12e (refer FIG. 1).

  The substrate holding unit moving mechanism 11 is composed of an XYZ robot. The operation of the substrate holding unit 11 is controlled by the control device 16 to move the substrate holding unit 12 in a horizontal plane (including rotation), and the upper surface of the clamp member 12e is raised. An “upward position” located in a horizontal plane W1 having a height H1 (the height of the lower surface of the mask 13) and a “lower position” located in a horizontal plane W2 (FIG. 1) having a second height H2 lower than the height H1. In the vertical direction (Z-axis direction).

  1 and 2, the camera unit 14 includes a lower imaging camera 14a as a lower imaging unit with an imaging field of view directed downward, and an upper imaging camera 14b as an upper imaging unit with an imaging field of view directed upward. As shown in FIG. 2, the base 10 has a Y-axis beam 21a provided extending in the Y-axis direction, and an X provided extending in the X-axis direction and movable on the Y-axis beam 21a in the Y-axis direction. A camera unit moving table 21 including a moving stage 21c provided to be movable in the X-axis direction on the axial beam 21b and the X-axis beam 21b is provided, and the camera unit 14 is provided on the moving stage 21c of the camera unit moving table 21. It is attached.

  The camera unit moving mechanism 22 (FIG. 1) whose operation is controlled by the control device 16 moves the X-axis beam 21b in the Y-axis direction relative to the Y-axis beam 21a and moves the moving stage 21c relative to the X-axis beam 21b in the X-axis direction. The camera unit 14 is moved in a horizontal plane W3 (FIG. 1) having a third height H3 between the first height H1 and the second height H2.

  The imaging operation of the lower imaging camera 14a and the imaging operation of the upper imaging camera 14b are controlled by the control device 16, and image data obtained by the imaging operation of the lower imaging camera 14a and image data obtained by the imaging operation of the upper imaging camera 14b. Is sent to the control device 16 and is recognized by the image recognition unit 16a (FIG. 1) of the control device 16.

  In FIG. 1, a squeegee unit 15 is a base portion that is movable in the horizontal plane direction (left and right direction in FIG. 1) above a mask 13 by the operation of a squeegee unit moving mechanism 15M comprising an orthogonal table mechanism (not shown) and its actuator. Each squeegee 15b is provided by a pneumatic cylinder 15c attached to the base portion 15a. The squeegee 15b is provided with two squeegees 15b provided opposite to the moving direction of the base portion 15a. The lower part of the base part 15a is raised and lowered independently. The control device 16 controls the operation of the squeegee unit moving mechanism 15M and the elevation control of the squeegee 15b by the operation of each pneumatic cylinder 15c.

  As shown in FIGS. 1 and 2, one clamp member 12e constituting the substrate holding unit 12 extends in the horizontal direction outside the clamp member 12e (the side opposite to the side that clamps the substrate 2). A jig member 30 made of a transparent material (for example, a glass material) having a calibration mark Q on the lower surface is attached. Since the lower surface of the jig member 30 is the same height as the upper surface of the clamp member 12e, the upper surface of the clamp member 12e, the upper surface of the substrate 2, and the calibration mark Q are the same when the substrate 2 is held by the clamp member 12e. When the substrate holding unit 12 is moved up and down beyond the horizontal plane W3 of the third height H3, which is the moving height of the camera unit 14, by the substrate holding unit moving mechanism 11, the substrate holding unit moving mechanism 11 moves up and down. The calibration mark Q also moves up and down beyond the third height H3. Accordingly, the calibration mark Q can be imaged from above with the lower imaging camera 14a and imaged from below with the upper imaging camera 14b, in combination with the jig member 30 made of a transparent material.

  That is, in the present embodiment, the jig member 30 is attached to the substrate holding unit 12 and is imaged from above by the lower imaging camera 14a and the upper imaging camera at the height of the upper surface of the substrate 2 held by the substrate holding unit 12. A calibration mark Q that can be imaged from below by 14b is positioned.

  In the screen printing machine 1 having such a configuration, before the screen printing operation for screen-printing the paste Pt on the substrate 2, the misalignment calibration value is calculated according to the procedure shown in the flowchart of FIG. The positional deviation calibration value calculated here is used when the substrate 2 is vertically aligned with respect to the mask 13 in the screen printing operation described later. The optical axis J1 of the lower imaging camera 14a and the upper imaging camera 14b are used. When at least one of the optical axes J2 is deviated from or tilted with respect to the optical axes J1 and J2 in the design data, or when the moving track of the substrate holding unit 12 is tilted from the vertical direction (that is, the substrate 2), the electrode 2a of the substrate 2 and the pattern hole 13h of the mask 13 are aligned with each other without misalignment. Is to be able to.

  The control device 16 shows the coordinates (Xcs, Ycs, H3) of the calibration position calculation camera position Cs determined in the horizontal plane W3 of the third height H3 shown in FIG. 4 and the calibration value calculation camera position Cs. The coordinates (Xcs, Ycs, H2) of the lower reference position SL located in the horizontal plane W2 having a height H2 immediately below are stored in the storage unit 16b (FIG. 1). Further, the control device 16 has the coordinates (Xca, Yca, H3) of the first positioning camera position Ca located in the horizontal plane W3 having a height H3 immediately below the first mask side mark Ma shown in FIG. The coordinates (Xcb, Ycb, H3) of the second alignment camera position Cb located in the horizontal plane W3 having a height H3 immediately below the second mask side mark Mb are stored in the storage unit 16b.

  When the controller 16 obtains the position deviation calibration value, first, as shown in FIG. 6A, the control device 16 controls the operation of the substrate holding unit moving mechanism 11 to provide a calibration mark Q provided on the jig member 30. Is adjusted so that is positioned at the lower reference position SL (substrate holding unit position adjusting step of step ST1 shown in FIG. 3). Next, the operation control of the camera unit moving mechanism 22 is performed, and the lower imaging camera 14a is advanced to the camera position Cs when calculating the calibration value, which is an upper position of the lower reference position SL (below step ST2 shown in FIG. 3). Imaging camera advancement process), the calibration mark Q positioned at the lower reference position SL is imaged from above by the lower imaging camera 14a to perform image recognition (imaging and image recognition process from above in step ST3 shown in FIG. 3), The XY coordinates of the position PQ2 at the second height H2 (lower position) of the calibration mark Q are calculated as “calibration mark lower position coordinates (X2, Y2)” (see FIG. 7; step ST4 shown in FIG. 3). Calibration mark lower position coordinate calculation step).

  When the calibration mark Q is captured by the lower imaging camera 14a and when the calibration mark Q is captured by the upper imaging camera 14b, the focal point is always the height of the lower surface of the jig member 30 (that is, the calibration mark Q is provided). The height).

  After calculating the calibration mark lower position coordinates (X2, Y2), the control device 16 controls the operation of the camera unit moving mechanism 22 and calculates the calibration value of the lower imaging camera 14a as shown in FIG. After retracting from the hour camera position Cs (lower imaging camera retracting step of step ST5 shown in FIG. 3), the substrate holding unit moving mechanism 11 is controlled to raise the substrate holding unit 12, and the calibration mark Q is The vertical position adjustment of the substrate holding unit 12 is performed so as to be positioned within the horizontal plane W1 having the height H1 (the substrate holding unit ascending step of step ST6 shown in FIG. 3). Here, if the movement trajectory when the substrate holding unit 12 is moved up and down is not tilted from the vertical direction, the calibration mark Q located in the horizontal plane W2 at the height H2 is the lower reference position SL (Xcs, Ycs). , H2) is located at a position SH (Xcs, Ycs, H1) immediately above (refer to FIGS. 4 and 6A, 6B, 6C).

  When the controller 16 raises the substrate holding unit 12 so that the calibration mark Q is positioned in the horizontal plane W1 having the height H1, the upper imaging camera 14b is moved to the camera position Cs (Xcs, Ycs, H3) is advanced (upward imaging camera advancement step of step ST7 shown in FIG. 3). Then, the upper imaging camera 14b images the calibration mark Q positioned in the horizontal plane W1 having the height H1 from below to perform image recognition (imaging and image recognition process from below in step ST8 shown in FIG. 3), and calibration. The XY coordinates of the position PQ1 at the first height H1 (upper position) of the work mark Q are calculated as “calibration mark upper position coordinates (X1, Y1)” (see FIGS. 6C and 7). (Step 3 of calculating calibration mark upper position coordinates shown in step ST9).

  The calibration mark lower position coordinate (X2, Y2) is calculated based on the image passing through the lower imaging camera 14a, and the calibration mark upper position coordinate (X1, Y1) is the image passing through the upper imaging camera 14b. Therefore, when the optical axis J1 of the lower imaging camera 14a is shifted or inclined from the optical axis J1 on the design data, the optical axis J2 of the upper imaging camera 14b is on the design data. When it is deviated or inclined from the optical axis J2, or when the moving track when the substrate holding unit 12 is moved up and down is inclined from the vertical direction, both coordinates (X2, Y2), (X1, Y1) are shown in the figure. As shown in FIG.

  After calculating the calibration mark lower position coordinates (X2, Y2) and the calibration mark upper position coordinates (X1, Y1) as described above, the control device 16 controls the operation of the camera unit moving mechanism 22 and moves upward. The imaging camera 14b is retracted from the camera position Cs when calculating the calibration value (upper imaging camera retracting step in step ST10 shown in FIG. 3). Then, the difference (X2−X1, difference) between the calculated calibration mark lower position coordinates (X2, Y2) and the calibration mark upper position coordinates (X1, Y1) in the positional deviation calibration value calculation unit 16c (FIG. 1). Y2-Y1) is calculated as a positional deviation calibration value (δx, δy) (see FIG. 7), and the calculated positional deviation calibration value (δx, δy) is stored in the storage unit 16b (position of step ST11 shown in FIG. 3). Deviation calibration value calculation / storage step) This completes the positional deviation calibration value calculation operation by the control device 16.

  Next, a description will be given of a procedure in the case where the screen printing machine 1 that has completed the above-described misregistration calibration value calculation work performs a screen printing work for screen printing the paste Pt on the substrate 2.

  Upon receiving the operation start operation input from the operator, the control device 16 first carries the substrate 2 supplied from the outside of the screen printing machine 1 by the conveyor 12b of the substrate holding unit 12, and clamps the substrate 2 by the clamp member 12e. (Step of loading and holding substrate in step ST21 shown in FIG. 9).

  After holding the substrate 2, the control device 16 determines whether it is necessary to obtain the position coordinates of the mask side marks Ma and Mb for positioning the substrate 2 with respect to the mask 13 (determination in step ST22 shown in FIG. 9). Step) Here, when the screen printing to be performed is the first screen printing after the replacement of the mask 13, the control device 16 satisfies the condition set by the operator of the screen printing machine 1 (for example, the screen printing). When the number of substrates 2 on which printing has been performed reaches a predetermined number, when the actual screen printing time reaches a predetermined time, or when the day of the screen printing operation starts, the mask side mark It is determined that it is necessary to obtain the position coordinates of Ma and Mb.

  When the control device 16 determines in step ST22 that it is necessary to obtain the position coordinates of the mask side marks Ma and Mb, the control device 16 positions the upper imaging camera 14b at the first alignment camera position Ca. Then, the first mask side mark Ma is imaged from the lower side by the upper imaging camera 14b and image recognition is performed, whereby the XY coordinates of the position PMa (at the height H1) of the first mask side mark Ma are set to “first”. 1 mask side mark position coordinates (XMa, YMa) ”(FIG. 8B), the upper imaging camera 14b is positioned at the second alignment camera position Cb, and then the upper imaging camera 14b. The second mask side mark Mb is picked up from below and image recognition is performed, whereby the XY coordinates of the position PMb (at the height H1) of the second mask side mark Mb are expressed as “ 2 of the mask-side mark position coordinates (XMB, YMB) "is calculated as (FIG 8 (b)) (mask side mark position coordinate calculating step of step ST23 shown in FIG. 9). Then, the calculated first mask side mark position coordinates (XMa, YMa) and second mask side mark position coordinates (XMb, YMb) are stored in the storage unit 16b (mask side mark in step ST24 shown in FIG. 9). Position coordinate storage step).

  The control device 16 calculates and stores the first mask side mark position coordinates (XMa, YMa) and the second mask side mark position coordinates (XMb, YMb) (or mask side marks Ma, Mb in step ST22). If it is determined that it is not necessary to obtain the position coordinates of the first substrate, the operation of the substrate holding unit moving mechanism 11 is controlled, and the first substrate provided on the substrate 2 held by the substrate holding unit 12 as shown in FIG. The side mark ma is positioned in a horizontal plane W2 having a height H2 substantially directly below the camera position Ca during the first alignment, and the second substrate side mark mb is approximately immediately below the camera position Cb during the second alignment. It lies within a horizontal plane W2 having a height H2.

  As described above, the control device 16 has the first substrate side mark ma positioned in the horizontal plane W2 having a height H2 almost immediately below the camera position Ca at the time of the first alignment, and the second substrate side mark mb is When it is positioned within the horizontal plane W2 having a height H2 almost immediately below the camera position Cb at the time of the second alignment, the camera unit moving mechanism 22 is controlled so as to capture the lower position at the camera position Ca at the time of the first alignment. The camera 14a is positioned, the first substrate side mark ma is imaged from above by the lower imaging camera 14a, and image recognition is performed, whereby the position Pma at the second height H2 of the first substrate side mark ma is determined. The XY coordinates are calculated as “first board side mark position coordinates (Xma, Yma)” (FIG. 8A), and the lower imaging camera 14a is positioned at the second alignment camera position Cb. The second substrate side mark mb is picked up from above by the imaging camera 14a and image recognition is performed, so that the XY coordinates of the position Pmb at the second height H2 of the second substrate side mark mb can be expressed as “second”. Substrate side mark position coordinates (Xmb, Ymb) ”(FIG. 8A) are calculated (substrate side mark position coordinate calculation step of step ST25 shown in FIG. 9).

  When the control device 16 calculates the first substrate-side mark position coordinates (Xma, Yma) and the second substrate-side mark position coordinates (Xmb, Ymb), the first substrate-side mark position coordinates (Xma, Yma) and The second substrate-side mark position coordinates (Xmb, Ymb) are calibrated using the positional deviation calibration values (δx, δy) stored in the storage unit 16b (calibration step in step ST26 shown in FIG. 9).

  Specifically, the calibration is performed by subtracting δx of the positional deviation calibration value from the X coordinate of the first substrate side mark position coordinate (Xma, Yma) and the first substrate side mark position coordinate (Xma, Yma). The first substrate-side mark position coordinate (Xma, Yma) is calibrated as (Xma-δx, Yma-δy) by subtracting the displacement calibration value δy from the Y coordinate, and the second substrate-side mark position coordinate (Xmb). , Ymb), the second substrate side mark by subtracting the displacement calibration value δx from the X coordinate, and by subtracting the displacement calibration value δy from the Y coordinate of the first substrate side mark position coordinate (Xmb, Ymb). The position coordinates (Xmb, Ymb) are calibrated as (Xmb−δx, Ymb−δy) (FIG. 8A).

  When the controller 16 obtains the first substrate-side mark position coordinates after calibration (Xma-δx, Yma-δy) and the second substrate-side mark position coordinates after calibration (Xmb-δx, Ymb-δy), The first substrate side mark position coordinates after calibration (Xma-δx, Yma-δy) and the second substrate side mark position coordinates after calibration (Xmb-δx, Ymb-δy) are obtained in step ST23 ( Alternatively, from the first mask side mark position coordinates (XMa, YMa) and the second mask side mark position coordinates (XMb, YMb) (stored in the storage unit 16b), the first substrate side mark ma is the first mask. The amount of movement (X-axis direction) of the substrate holding unit moving mechanism 11 required to position the second substrate side mark mb directly below the side mark Ma and to position the second substrate side mark mb directly below the second mask side mark Mb. The amount of travel to The amount of movement in the Y-axis direction and the amount of rotation about the Z-axis) are calculated. Then, the substrate holding unit moving mechanism 11 is operated so that the substrate holding unit 12 moves by the calculated movement amount, and the mask 13 and the substrate 2 are vertically aligned (alignment of step ST27 shown in FIG. 9). Process).

  When the controller 16 aligns the substrate 2 with respect to the mask 13 as described above, the control device 16 controls the operation of the substrate holding unit moving mechanism 11 so that the substrate holding unit 12 holding the substrate 2 is moved with respect to the mask 13. As a result, the substrate 2 is brought into contact with the lower surface of the mask 13 (contact process in step ST28 shown in FIG. 9). As a result, the electrode 2a of the substrate 2 and the pattern hole 13h of the mask 13 are brought into agreement.

  As described above, in the present embodiment, the control device 16 uses the lower imaging camera 14a to image both the board-side marks ma and mb provided on the board 2 and calculates the positions of the both board-side marks ma and mb (first number). The first substrate side mark position coordinates (Xma, Yma) and the second substrate side mark position coordinates (Xmb, Ymb)) and both mask side marks Ma, Mb provided on the mask 13 are imaged by the upper imaging camera 14b. (The first mask side mark position coordinates (XMa, YMa) and the second mask side mark position coordinates (XMb, YMb)) calculated in detail ( After the mask 13 and the substrate 2 are vertically aligned, the substrate holding unit 12 is moved upward to add the substrate 2 to the lower surface of the mask 13 (with calibration using displacement calibration values (δx, δy)). It functions as a substrate holding unit movement control unit that is brought into contact with the substrate.

  When the control device 16 brings the substrate 2 into contact with the mask 13, the controller 16 performs squeegeeing with the squeegee 15b to transfer the paste Pt previously supplied onto the mask 13 to the electrode 2a of the substrate 2 (step ST29 shown in FIG. 9). Fig. 10 (a)).

  Specifically, this squeezing is performed by lowering one of the two squeegees 15b included in the squeegee unit 15 and moving the base portion 15a in the horizontal direction while maintaining the state in contact with the upper surface of the mask 13 (FIG. 10). (A) It moves by moving to the arrow A) shown in the inside. As a result, the squeegee 15b slides on the mask 13, and the paste Pt on the mask 13 is scraped by the squeegee 15b and pushed into the pattern holes 13h of the mask 13, and transferred onto the electrodes 2a of each substrate 2.

  Thus, in this embodiment, the squeegee 15b slides on the mask 13 in contact with the substrate 2 and prints the paste on the electrode of the substrate through the pattern hole of the mask.

  After squeezing and transferring the paste Pt to the electrode 2 a of the substrate 2, the control device 16 operates the substrate holding unit moving mechanism 11 to lower the substrate holding unit 12 and separate the substrate 2 from the mask 13. (Arrow B shown in FIG. 10B), plate separation is performed (the plate separation step of step ST30 shown in FIG. 9). As a result, the paste Pt remains on the electrode 2a of the substrate 2, and the paste Pt is printed on the substrate 2 (FIG. 10B).

  After releasing the plate, the control device 16 releases the holding of the substrate 2 by the pair of clamp members 12e (substrate holding releasing process in step ST31 shown in FIG. 9), and lowers the substrate 2 by the substrate lifting cylinder 12d. The substrate 2 is lowered onto the conveyor 12b, and the substrate 2 is carried out of the screen printer 1 by the conveyor 12b to complete the screen printing operation for one substrate 2 (substrate carrying-out process of step ST32 shown in FIG. 9).

  As described above, the screen printing machine 1 according to the present embodiment is attached to the substrate holding unit 12 and images from above with the lower imaging camera 14 a at the height of the upper surface of the substrate 2 held by the substrate holding unit 12. The jig member 30 on which the calibration mark Q that can be imaged from below by the upper imaging camera 14b is positioned, and the calibration mark Q is lower than the first height H1 that is the height of the lower surface of the mask 13. The calibration mark Q is calculated by being imaged from above by the lower imaging camera 14a with the vertical position adjustment of the substrate holding unit 12 performed so as to be positioned at the height H2. The vertical position adjustment of the substrate holding unit 12 is performed so that the coordinates (X2, Y2) of the position PQ2 at the height H2 of 2 and the calibration mark Q are positioned at the first height H1. In this state, the difference (horizontal plane) between the calibration mark Q and the coordinates (X1, Y1) of the position PQ1 at the first height H1 of the calibration mark calculated by being imaged from below by the upper imaging camera 14b. The controller 16 serving as the substrate holding unit movement control unit includes a positional deviation calibration value calculation unit 16c of the control device 16 that calculates the inward difference) as the positional deviation calibration values (δx, δy). Using the positional deviation calibration values (δx, δy) calculated by the value calculation unit 16c, the mask 13 and the substrate 2 are vertically aligned, and then the substrate holding unit 12 is lifted with respect to the mask 13 to mask 13 The substrate 2 is brought into contact with the lower surface of the substrate.

  Further, the screen printing method by the screen printer 1 in the present embodiment is the screen printing method by the screen printer 1, and the first height H1 in which the calibration mark Q is the height of the lower surface of the mask 13. The calibration mark Q is imaged from above by the lower imaging camera 14a while the vertical position of the substrate holding unit 12 is adjusted so as to be positioned at the lower second height H2, and the second calibration mark Q is imaged. The step of calculating the coordinates (X2, Y2) of the position PQ2 at the height H2 (calibration mark lower position coordinate calculation step of step ST4), the substrate so that the calibration mark Q is positioned at the first height H1. The calibration mark Q is imaged from below by the upper imaging camera 14b with the vertical position adjustment of the holding unit 12, and the position P of the calibration mark Q at the first height H1 is obtained. The process of calculating the coordinates (X1, Y1) of 1 (calibration mark upper position coordinate calculation process of step ST9), the coordinates of the calculated position PQ2 at the second height H2 of the calibration mark Q and the calibration mark Q A step of calculating a difference in the horizontal plane direction from the coordinates of the position PQ1 at the first height H1 as a positional deviation calibration value (δx, δy) (a positional deviation calibration value calculation / storage step in step ST11), Using the calculated displacement calibration values (δx, δy), the mask 13 and the substrate 2 are vertically aligned, and then the substrate holding unit 12 is raised with respect to the mask 13 so that the substrate 2 contacts the lower surface of the mask 13. And the squeegee 15b is slid on the mask 13 brought into contact with the substrate 2 and the pace is formed on the electrode 2a of the substrate 2 through the pattern hole 13h of the mask 13. This includes a step (squeezing step) of printing the toner Pt.

  In the screen printing machine 1 and the screen printing method according to the present embodiment, imaging from above and imaging by the lower imaging camera 14a located at the height of the upper surface of the substrate 2 when the substrate 2 is held by the substrate holding unit 12. The calibration mark Q that can be imaged from below by the camera 14b is moved up and down together with the substrate holding unit 12, and is positioned at a second height H2 that is lower than the first height H1 that is the height of the lower surface of the mask 13. The coordinates (X2, Y2) of the position PQ2 at the second height H2 of the calibration mark Q calculated by imaging the calibration mark Q from above with the lower imaging camera 14a and the height of the lower surface of the mask 13 The position PQ at the first height H1 of the calibration mark Q calculated by imaging the calibration mark Q positioned at the first height H1 from below with the upper imaging camera 14b. Since the difference in the horizontal plane direction from the coordinate (X1, Y1) of the current position is calculated as the positional deviation calibration value (δx, δy), it is simple and accurate and without interrupting the screen printing operation. A misalignment calibration value can be obtained at any time.

  In the above-described embodiment, the jig member 30 is made of a transparent material attached to the upper surface of the clamp member 12e and provided with the calibration mark Q on the lower surface. A calibration mark is provided at the height of the upper surface of the substrate 2 when the substrate 2 is held by the unit 12 and can be imaged from above by the lower imaging camera 14a and imaged from below by the upper imaging camera 14b. That's fine. Therefore, on the assumption that the jig member 30 is made of a transparent material, the jig member 30 is attached to the clamp member 12e so that the upper surface is the same height as the upper surface of the clamp member 12e, and the calibration mark Q is provided on the upper surface. It may be a thing.

  Alternatively, as shown in FIGS. 11A and 11B, the jig member 30 has a tapered hole 40 penetrating in the thickness direction (the material is preferably not transparent). Of the upper and lower opening edges (opening edges formed on the upper surface and the lower surface of the jig member 30, respectively, although a circular shape is preferable but not limited to a circular shape), an opening edge 40a having a relatively small size is formed. The surface may be attached to the clamp member 12e so as to be positioned at the height of the upper surface of the substrate 2 when the substrate 2 is held by the substrate holding unit 12 (the upper surface of the clamp member 12e). In this case, the opening edge 40a on the smaller dimension side corresponds to the calibration mark Q, and the focus is the dimension when the calibration mark Q is imaged by the lower imaging camera 14a and when the calibration mark Q is imaged by the upper imaging camera 14b. Is adjusted to the height of the surface of the jig member 30 on which the small opening edge 40a is formed (the lower surface 30a of the jig member 30 in FIG. 11A and the upper surface 30b of the jig member 30 in FIG. 11B). Like that.

  Provided is a screen printing machine and a screen printing method capable of obtaining a positional deviation calibration value easily and accurately at any time without interrupting the screen printing operation.

1 Screen Printer 2 Substrate 2a Electrode 12 Substrate Holding Unit (Substrate Holding Unit)
13 Mask 13h Pattern hole 14a Lower imaging camera (lower imaging part)
14b Upper imaging camera (upper imaging unit)
15b Squeegee 16 control device (substrate holding unit movement control unit)
16c Position shift calibration value calculation unit 30 Jig member Q Calibration mark Ma First mask side mark (mask side mark)
Mb Second mask side mark (mask side mark)
H1 1st height H2 2nd height (delta) x, (delta) y Position shift calibration value ma 1st board | substrate side mark (board | substrate side mark)
mb Second substrate side mark (substrate side mark)
Pt paste

Claims (2)

A substrate holding unit for holding a substrate having an electrode on the upper surface, a mask provided with a pattern hole corresponding to the electrode of the substrate, a lower imaging unit with the imaging field facing downward, and an upper with the imaging field facing upward The imaging side and the position of the substrate side mark calculated by imaging the substrate side mark provided on the substrate by the lower imaging unit and the mask side calculated by imaging the mask side mark provided on the mask by the upper imaging unit A substrate holding unit movement control unit that raises and lowers the substrate holding unit based on the mark position and then raises the substrate holding unit to contact the lower surface of the mask, and the mask that is in contact with the substrate. A screen printing machine provided with a squeegee that slides on and prints a paste on an electrode of a substrate through a pattern hole of a mask,
A jig that is attached to the substrate holding unit and has a calibration mark positioned at the height of the upper surface of the substrate held by the substrate holding unit and capable of imaging from above by the lower imaging unit and imaging from below by the upper imaging unit Members,
The calibration mark is positioned downward in a state in which the position of the substrate holding portion is adjusted so that the calibration mark is positioned at a second height lower than the first height which is the height of the lower surface of the mask. The coordinates of the position at the second height of the calibration mark calculated by being imaged from above by the imaging unit and the vertical position of the substrate holder so that the calibration mark is positioned at the first height In a state where the adjustment is performed, the calibration mark is imaged from below by the upper imaging unit, and a difference in the horizontal plane direction from the coordinates of the position at the first height of the calibration mark is determined. A positional deviation calibration value calculation unit for calculating as a deviation calibration value,
The substrate holding unit movement control unit performs vertical alignment of the mask and the substrate using the positional deviation calibration value calculated by the positional deviation calibration value calculation unit, and then raises the substrate holding unit with respect to the mask to mask A screen printing machine characterized in that a substrate is brought into contact with the lower surface of the screen. A substrate holding unit for holding a substrate having an electrode on the upper surface, a mask provided with a pattern hole corresponding to the electrode of the substrate, a lower imaging unit with the imaging field facing downward, and an upper with the imaging field facing upward The imaging side and the position of the substrate side mark calculated by imaging the substrate side mark provided on the substrate by the lower imaging unit and the mask side calculated by imaging the mask side mark provided on the mask by the upper imaging unit A substrate holding unit movement control unit that raises and lowers the substrate holding unit based on the mark position and then raises the substrate holding unit to contact the lower surface of the mask, and the mask that is in contact with the substrate. A squeegee that slides on the substrate and prints paste on the electrode of the substrate through the pattern hole of the mask, and is attached to the substrate holder and is lowered to the height of the upper surface of the substrate held by the substrate holder. A screen printing method by screen printing machine having a jig member which imaging is to position the calibration mark possible from below by imaging and upper imaging unit from the direction,
The image of the calibration mark is imaged downward in a state in which the position of the substrate holder is adjusted in the vertical direction so that the calibration mark is positioned at a second height lower than the first height which is the height of the lower surface of the mask. Imaging from above by the unit to calculate the coordinates of the position at the second height of the calibration mark;
The calibration mark is imaged from below by the upper imaging unit in a state where the vertical position of the substrate holding unit is adjusted so that the calibration mark is positioned at the first height, and the first of the calibration marks is captured. Calculating coordinates of a position at a height of;
A difference in the horizontal plane direction between the calculated coordinate of the position of the calibration mark at the second height and the coordinate of the position of the calibration mark at the first height is calculated as a positional deviation calibration value. Process,
Performing the vertical alignment of the mask and the substrate using the calculated displacement calibration value, and then raising the substrate holding part with respect to the mask and bringing the substrate into contact with the lower surface of the mask;
And a step of sliding a squeegee on a mask in contact with the substrate and printing a paste on an electrode of the substrate through a pattern hole of the mask.

Images