JP2011189672A - Screen printing machine and method of measuring stuck amount of paste in the screen printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen printing machine that can accurately determine a remaining paste amount on a mask and that can prevent paste from being replenished unnecessarily on a mask, and to provide a method of measuring a stuck amount of paste in the screen printing machine. <P>SOLUTION: After paste Pst is transferred onto a substrate 2, a squeegee elevation shaft 61 is elevated with respect to a mask 13. Then, while the squeegee 14 is separated from the mask 13, a load in the axial direction of the squeegee elevation shaft 61 is measured and on the basis of the measured load in the axial direction of the squeegee elevation shaft 61, the amount of paste stuck to the squeegee 14 is computed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a screen printing machine that prints a paste on a substrate through a mask, and a method for measuring the amount of adhered paste in the screen printing machine.

  A screen printer that prints a paste such as solder paste on a board contacts the mask with a pattern hole corresponding to the electrode on the board in contact with the board so that the pattern hole is vertically aligned, and then the paste is supplied By sliding the squeegee on the mask and scraping the paste, the paste is transferred to the electrode through the pattern hole of the mask (for example, Patent Document 1).

  In such a screen printing machine, the amount of paste on the mask decreases as the screen printing operation proceeds, so the squeegee that has finished transferring the paste is raised to its original position (in this state, the squeegee is The operator visually confirms the amount of paste remaining on the mask, and if it is determined that the amount of paste remaining on the mask is insufficient, the operator should manually replenish the mask with additional paste. I was doing.

JP 2000-263754 A

  However, since the paste has a high viscosity and easily adheres to the squeegee, a large amount of paste may remain attached to the squeegee after the paste is transferred. In this case, even though there is actually a sufficient amount of paste, the operator cannot determine the paste attached to the mask, so it is determined that the amount of paste is insufficient, and more paste than necessary is needed. There was a problem in that replenishment could lead to high costs.

  Therefore, the present invention can accurately determine the amount of paste remaining on the mask, and can prevent the paste from being replenished more than necessary on the mask. An object is to provide a quantity measuring method.

  The screen printing machine according to claim 1, wherein the screen is in contact with the mask from above, the mask being in contact with the upper surface of the substrate, the squeegee lifting shaft that is raised and lowered relative to the mask, and the lower end of the squeegee lifting shaft. The squeegee lifting shaft is moved relative to the mask in the horizontal plane direction so that it slides on the mask and the paste supplied on the mask is transferred to the substrate, and the axial load of the squeegee lifting shaft is measured. The load measuring means for performing the measurement and the axial load of the squeegee lifting shaft measured by the load measuring means in a state where the squeegee lifting shaft is lifted with respect to the mask and the squeegee is separated from the mask after the paste is transferred to the substrate. And an attached paste amount calculating means for calculating the amount of paste attached to the squeegee based on it.

  The screen printing machine according to claim 2 is the screen printing machine according to claim 1, wherein the load measuring means includes a load cell attached to an elastic body interposed between the squeegee lifting shaft and the squeegee. Become.

  The method for measuring the amount of paste in the screen printing machine according to claim 3, wherein the mask is brought into contact with the upper surface of the substrate, and the squeegee attached to the lower end of the squeegee lifting shaft that is raised and lowered relative to the mask is used as the mask from above. A step of abutting, and a paste supplied on the mask by sliding the squeegee on the mask by moving the squeegee lifting shaft relative to the mask in a horizontal plane direction with the squeegee abutting on the mask. The step of transferring to the substrate, the step of measuring the axial load of the squeegee lifting shaft with the squeegee lifting shaft raised from the mask and the squeegee separated from the mask after the paste was transferred to the substrate, Calculating the amount of paste adhering to the squeegee based on the axial load of the squeegee lifting shaft.

  The method for measuring the amount of adhered paste in the screen printer according to claim 4 is the method for measuring the amount of adhered paste in the screen printer according to claim 3, wherein the axial load of the squeegee elevating shaft is determined by the squeegee elevating shaft and the squeegee. It measures with the load cell attached to the elastic body interposed between.

  The paste amount measuring method in the screen printing machine according to claim 5 is a method for measuring the amount of adhered paste in the screen printing machine according to claim 3 or 4, wherein the squeegee lifting shaft is moved after the paste is transferred to the substrate. The process of measuring the axial load of the squeegee lifting shaft in a state where the squeegee is lifted with respect to the mask and separated from the mask, the paste is transferred to the substrate, and then the mask is brought into contact with the substrate to be screen printed next. It was executed immediately before the step of bringing the squeegee into contact.

  In the present invention, after the paste is transferred to the substrate, the squeegee lifting shaft is lifted with respect to the mask, and the squeegee is measured based on the axial load (tensile load) of the squeegee lifting shaft measured with the squeegee separated from the mask. The amount of paste attached to the squeegee is calculated (measured). If the amount of paste attached to the squeegee is large, appropriate measures such as peeling off the paste from the squeegee are taken to determine the amount of paste remaining on the mask. Therefore, it is possible to prevent the paste from being replenished more than necessary on the mask.

The top view of the screen printer in one embodiment of the present invention The front view of the screen printer in one embodiment of the present invention The side view of the screen printer in one embodiment of the present invention The top view of the mask installed in the mask holder with which the screen printing machine in one embodiment of this invention is equipped, and the mask holder The perspective view of the vicinity part of the squeegee with which the screen printer in one embodiment of this invention is provided The front view of the vicinity part of the squeegee with which the screen printer in one embodiment of this invention is provided The block diagram which shows the control system of the screen printer in one embodiment of this invention The flowchart of the main routine which shows the procedure of the screen printing operation which the screen printer in one embodiment of this invention performs The flowchart of the subroutine which shows the procedure of the screen printing operation which the screen printer in one embodiment of this invention performs The flowchart of the subroutine which shows the procedure of the screen printing operation which the screen printer in one embodiment of this invention performs (A) (b) (c) Explanatory drawing of the measurement procedure of the tension of the mask in the screen printer in one embodiment of the present invention (A) (b) The front view of the board | substrate holding | maintenance movement unit with which the screen printer in one embodiment of this invention is provided. (A) (b) Side view of the substrate holding and moving unit provided in the screen printer in one embodiment of the present invention. (A) (b) Side view of the substrate holding and moving unit provided in the screen printer in one embodiment of the present invention. (A) (b) (c) Side view of the substrate holding and moving unit provided in the screen printing machine according to the embodiment of the present invention. (A) (b) Explanatory drawing of the procedure of the foreign material detection in the screen printer in one embodiment of this invention (A) (b) Explanatory drawing of the procedure of the foreign material detection in the screen printer in one embodiment of this invention (A) (b) Explanatory drawing of the measuring method of the adhesion paste of the squeegee in the screen printer in one embodiment of this invention. (A) (b) (c) Side view of the substrate holding and moving unit provided in the screen printing machine according to the embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. A screen printing machine 1 shown in FIGS. 1, 2 and 3 is a kind of electronic component mounting apparatus constituting an electronic component mounting line for mounting substrate production. A substrate 2 is carried in and placed on the surface of the substrate 2. After performing screen printing for transferring a paste Pst (see FIG. 3) such as a solder paste or a conductive paste onto the provided electrode 3, the substrate 2 is transferred to an electronic component mounting machine (not shown) on the downstream side. The operation to carry out is executed continuously. Hereinafter, for convenience of explanation, the transport direction of the substrate 2 in the screen printing machine 1 is the X axis direction (left and right direction in FIG. 1), and the horizontal direction perpendicular to the X axis direction is the Y axis direction (up and down direction in FIG. 1). ) And the vertical direction is the Z-axis direction. The Y-axis direction is the front-rear direction of the screen printing machine 1 and the X-axis direction is the horizontal (left-right) direction of the screen printing machine 1. Further, in the front-rear direction, the operator OP (FIG. 1) of the screen printing machine 1 performs the operation on the screen printing machine 1 (below the paper surface in FIG. 1) is the front side of the screen printing machine 1, and the opposite side (see FIG. 1). 1) is the rear side of the screen printer 1.

  1, 2, and 3, the screen printing machine 1 according to the present embodiment includes a substrate holding / moving unit 12 provided on a base 11, and a metal thin plate provided above the substrate holding / moving unit 12. A plate-shaped mask 13 made of a material, a pair of front and rear squeegees 14 and a camera unit 15 are provided.

  2 and 3, the substrate holding / moving unit 12 includes a horizontal moving unit 21, a lifting / lowering unit 22, a conveyor unit 23, and a substrate holding unit 24.

  2 and 3, the horizontal moving unit 21 moves to the Y table 21a that moves in the Y-axis direction with respect to the base 11 by the operation of the Y table drive motor My, and to the Y table 21a by the operation of the X table drive motor Mx. The X table 21b that moves in the X axis direction, the θ table 21c that rotates around the Z axis with respect to the X table 21b, the base table 21d that is fixed to the upper surface of the θ table 21c, and the upper surface of the base table 21d that extends upward It consists of a plurality of lift table guides 21e provided.

  2 and 3, the elevating unit 22 is provided to extend upward from the upper surface of the elevating table 22a and the elevating table 22a which are guided by a plurality of elevating table guides 21e of the horizontal moving unit 21 and elevate with respect to the base table 21d. And a plurality of support unit lifting guides 22b.

  In FIG. 3, the conveyor unit 23 is attached to the upper end of the receiving unit elevating guide 22b and supported by a pair of front and rear belt conveyor supporting members 23a that elevate and lower with respect to the base table 21d together with the elevating table 22a, and each belt conveyor supporting member 23a. The front and rear belt conveyors 23b are moved forward and backward in the X-axis direction, and the front and rear belt conveyors 23b are operated in synchronization, whereby the substrate 2 is transported in the X-axis direction.

  2 and 3, the substrate holding part 24 is a pair of front and rear clamping members 24a (see also FIG. 1) provided on the upper parts of the front and rear belt conveyor support members 23a provided in the conveyor part 23 so as to be movable in the Y-axis direction. ), A lower receiving unit support table 24b which is guided by the lower receiving unit elevating guide 22b and which is moved up and down, and a lower receiving unit 24c provided on the upper surface of the lower receiving unit supporting table 24b. The lower receiving unit 24c supports the substrate 2 on the conveyor unit 23 from below by moving up and down with respect to the lifting table 22a together with the lower receiving unit support table 24b. The front and rear clamp members 24a are clamped by sandwiching both sides in the Y-axis direction of the substrate 2 supported at both ends by the front and rear belt conveyors 23b and supported by the lower receiving unit 24c from the outside of the substrate 2.

  In FIGS. 1 and 2, at the positions on both sides in the X-axis direction (upstream side and downstream side in the conveyance direction of the substrate 2) of the conveyor unit 23 that constitutes the substrate holding and moving unit 12, the screen printing machine 1 (see FIG. 1 and the substrate loading conveyor 25 that conveys (loads) the substrate 2 that has been loaded from the left side of the sheet of FIG. 2 and delivers it to the conveyor unit 23, and the substrate 2 that has been delivered from the conveyor unit 23 to the outside of the screen printer 1 A substrate carry-out conveyor 26 for carrying (carrying out) is provided (on the right side in FIG. 1 and FIG. 2).

  In FIG. 1 and FIG. 2, a pair of portal frames 28 are provided on the base 11 so as to straddle the substrate carry-in conveyor 25 and the substrate carry-out conveyor 26 in the Y-axis direction. The holder 30 is supported. The mask holder 30 has a pair of front and rear guide members 31 that are attached to the portal frame 28 and extend in the X-axis direction above the substrate holding portion 24 provided in the substrate holding and moving unit 12 and a pair of guide members. 31 comprises a pair of left and right mask support rails 32 extending in the Y-axis direction. The mask 13 is held in a horizontal position above the substrate holding and moving unit 12 by being supported at both left and right by left and right mask support rails 32 provided in the mask holder 30 (see also FIG. 4).

  In FIG. 1 and FIG. 4, the mask 13 is supported by a mask frame 13w made of a rectangular frame-like member in plan view, and a rectangular region surrounded by the mask frame 13w has a plurality of areas on the substrate 2. A large number of pattern holes 13 a corresponding to the electrodes 3 are provided. That is, the mask 13 has a large number of pattern holes 13 a formed according to the arrangement of the electrodes 3 on the substrate 2.

  In FIG. 1, two sets of substrate-side positioning marks mk are provided at diagonal positions of the substrate 2. On the other hand, in FIG. 4, the mask 13 is provided with a pair of mask side positioning marks MK arranged corresponding to the substrate side positioning marks mk. When the substrate 2 is brought into contact with the mask 13 with the substrate-side positioning mark mk and the mask-side positioning mark MK aligned vertically, the electrode 3 of the substrate 2 and the pattern hole 13a of the mask 13 are aligned vertically. Become.

  1 and 2, the pair of portal frames 28 support both ends of an X-axis stage 51 extending in the X-axis direction so as to be slidable in the Y-axis direction. A camera support stage 52 is provided on the X-axis stage 51 so as to be movable in the X-axis direction. The camera unit 15 is attached to the camera support stage 52. The camera unit 15 includes a first camera 15a whose imaging field is directed downward and a second camera 15b whose imaging field is directed upward (FIG. 3).

  In FIGS. 1 and 2, both ends of a squeegee base 60 extending in the X-axis direction are supported by the pair of portal frames 28, and the squeegee base 60 reciprocates in the Y-axis direction along the portal frame 28. It is free to move. The squeegee base 60 is provided with the pair of front and rear squeegees 14 opposed to each other in the Y-axis direction.

  5 and 6, a squeegee lifting shaft 61 composed of two ball screws is provided extending in the vertical direction at a position facing the Y-axis direction at the center of the upper surface of the squeegee base 60. Each of these two squeegee lifting shafts 61 includes a squeegee base 60, a cylindrical squeegee lifting shaft holding portion 62 provided on the upper surface of the squeegee base 60, and a bearing 62a (shown in FIG. 6) in the squeegee lifting shaft holding portion 62. As shown in the enlarged view), a cylindrical nut member 63 that is rotatably held around the vertical axis extends in the vertical direction.

  The squeegee raising / lowering shaft 61 and the nut member 63 are screwed together, and the squeegee raising / lowering shaft 61 penetrates a ring-shaped driven pulley 64 fixed to the upper portion of the nut member 63 in the vertical direction (is loosely fitted). It extends.

  The lower end of each squeegee lifting shaft 61 is coupled to the upper surface of a squeegee holder mounting member 65 that extends below the squeegee base 60 in the X-axis direction. 14 is attached.

  A pair of guide rods 66 are provided extending in the vertical direction at a position on the upper surface of the squeegee holder mounting member 65 with the squeegee lifting shaft 61 interposed therebetween. The pair of guide rods 66 extend vertically through a squeegee base 60 and a cylindrical rod guide portion 67 provided on the upper surface of the squeegee base 60.

  Each squeegee 14 has a squeegee holder 70 provided below the squeegee holder attaching member 65 so as to extend parallel to the squeegee holder attaching member 65 (that is, in the X-axis direction), and an upper end portion attached to the squeegee holder 70 so that the X-axis direction is provided. The squeegee main body 71 has a spatula-like shape extending in the direction.

  5 and 6, two squeegee lifting shaft drive motors 72 are provided on the upper surface of the squeegee base 60 at a position sandwiching the two squeegee lifting shaft holding portions 62 in the X-axis direction. These two squeegee lifting shaft drive motors 72 have a drive shaft 72a facing upward, and a drive pulley 73 is attached to each drive shaft 72a. A transmission belt is provided between one of the two driving pulleys 73 and one of the two driven pulleys 64 and between the other of the two driving pulleys 73 and the other of the two driven pulleys 64. 74 is stretched over.

  When the drive pulley 73 is rotated by the rotational drive of the drive shaft 72 a of the squeegee lifting shaft drive motor 72, the driven pulley 64 is rotated around its vertical axis (this axis coincides with the vertical axis of the squeegee lifting shaft 61) via the transmission belt 74. Since the nut member 63 is rotated integrally with the driven pulley 64, the squeegee lifting shaft 61 moves up and down with respect to the nut member 63 (that is, the squeegee base 60). Thereby, the squeegee holder attaching member 65 attached to the lower end of the squeegee raising / lowering shaft 61 is lifted and lowered while being guided by the pair of guide rods 66 and extending in the X-axis direction. The squeegee 14 attached to is also moved up and down with respect to the squeegee base 60 while maintaining the posture extending in the X-axis direction. Since the relative position in the vertical direction of the mask 13 and the squeegee base 60 does not change, the squeegee lifting shaft 61 moves up and down with respect to the mask 13.

  As described above, the lower end of the squeegee lifting shaft 61 is attached to the upper surface of the squeegee holder mounting member 65, but an elastic body 75 as a strain generating body is interposed between the squeegee lifting shaft 61 and the squeegee holder mounting member 65. A strain gauge type load cell 76 is attached to the elastic body 75. For this reason, when an axial load (compression load or tensile load) is applied to the squeegee lifting shaft 61 via the squeegee 14, the strain of the elastic body 75 that is elastically deformed in response to the load is detected by the load cell 76. Is measured as the axial load.

  In the screen printing machine 1 according to the present embodiment, the operations of the substrate carry-in conveyor 25 as the substrate carrying path for carrying the substrate 2, the conveyor unit 23 of the substrate holding and moving unit 12, and the substrate carry-out conveyor 26 are controlled by a control device 80 ( 7) is performed by controlling the operation of the substrate transport path operating mechanism 81 (FIG. 7) including an actuator (not shown), and the clamping operation of the substrate 2 by the clamp member 24a is performed by the controller 80 including an actuator (not shown). This is done by controlling the operation of the clamp member operating mechanism 82 (FIG. 7).

  Movement of the Y table 21a relative to the base 11 in the Y-axis direction, movement of the X table 21b relative to the Y table 21a in the X-axis direction, rotation of the θ table 21c relative to the X table 21b (ie, the base table 21d) around the Z axis The control device 80 operates the Y table drive motor My and the X table as described above for the operations of raising and lowering the lifting table 22a with respect to the base table 21d and raising and lowering the lower support unit support table 24b with respect to the lift table 22a (that is, lower support unit 24c). This is done by controlling the operation of the substrate holding and moving unit operating mechanism 83 (FIG. 7) including an actuator including the drive motor Mx.

  Movement of the camera unit 15 in the horizontal plane, that is, movement of the X-axis stage 51 in the Y-axis direction with respect to the pair of portal frames 28 and movement of the camera support stage 52 in the X-axis direction with respect to the X-axis stage 51 Each control is performed when the control device 80 controls the operation of the camera unit moving mechanism 84 (FIG. 7) including an actuator (not shown).

  The operation control of the squeegee base 60 for reciprocating the front and rear squeegees 14 in the Y-axis direction is performed by the control device 80 controlling a squeegee base moving mechanism 85 (FIG. 7) including an actuator (not shown). Further, the raising / lowering operation of each squeegee 14 with respect to the squeegee base 60 is performed by controlling the operation of the above-described two squeegee raising / lowering shaft drive motors 72 attached to the upper portion of the squeegee base 60.

  The first camera 15a constituting the camera unit 15 is controlled by the control device 80 to take an image of the substrate-side positioning mark mk of the substrate 2 held by the substrate holding unit 24 provided in the substrate holding and moving unit 12, and The two camera 15b is controlled by the control device 80 to image the mask side positioning mark MK provided on the mask 13. Both the image data obtained by the imaging of the first camera 15a and the image data obtained by the imaging of the second camera 15b are input to the control device 80 (FIG. 7). The value of the axial load of the squeegee lifting shaft 61 measured by the two load cells 76 provided corresponding to each squeegee 14 is also input to the control device 80 (FIG. 7).

  Next, the operation procedure of the screen printing machine 1 will be described with reference to the flowcharts of FIGS. 8 to 10 and the explanatory diagrams of FIGS. Here, FIG. 8 is a flowchart of a main routine of the operation of the screen printer 1, and FIGS. 9 and 10 are flowcharts of subroutines in the main routine.

  In the screen printing machine 1 according to the present embodiment, the tension of the mask 13 placed on the mask holder 30 is measured before executing the screen printing operation on the substrate 2 (mask tension measuring process shown in step ST1 of FIG. 8). . In measuring the tension of the mask 13, the control device 80 controls the operation of the squeegee base moving mechanism 85 to position one of the two squeegees 14 substantially above the center of the mask 13 installed in the mask holder 30. (FIG. 11A. Squeegee positioning step shown in step ST21 of FIG. 9), the squeegee lifting shaft driving motor 72 corresponding to the squeegee 14 is operated to lower the squeegee lifting shaft 61 with respect to the mask 13 ( 11A, the lower edge of the squeegee 14 is brought into contact with the central portion of the mask 13 before being brought into contact with the substrate 2 (FIG. 11B) .Squeegee contact shown in step ST22 of FIG. Process).

  When the control device 80 makes contact with the central portion of the mask 13 before the squeegee 14 is brought into contact with the substrate 2 as described above, the control device 80 lowers the squeegee lifting shaft 61 that makes the squeegee 14 contact with the central portion of the mask 13. (Arrow A2 shown in FIG. 11 (c)), the center portion of the mask 13 is pushed down (FIG. 11 (c). Mask pushing step shown in step ST23 of FIG. 9).

  The pressing amount δ (FIG. 11C) of the central portion of the mask 13 in this mask pressing step is set to such a magnitude that the mask 13 is bent slightly downward in the elastic region. By pushing down the central portion of the mask 13, the squeegee lifting shaft 61 receives a reaction force from the mask 13 via the squeegee 14 and the elastic body 75, and the squeegee lifting shaft 61 receives a compressive load F (FIG. 11) as an axial load. (C)) acts.

  When the central portion of the mask 13 is pushed down as described above, the control device 80 measures the axial load (compression load) F of the squeegee lifting shaft 61 with the mask 13 pushed down (step of FIG. 9). The load measurement step shown in ST24), and the tension of the mask 13 is calculated based on the relationship between the measured axial load F of the squeegee lifting shaft 61 and the amount of depression δ at the center of the mask 13 (step of FIG. 9). (Tension calculation step shown in ST25). At this time, the control device 80 lowers the squeegee lifting shaft 61 with which the squeegee 14 is brought into contact with the central portion of the mask 13 before being brought into contact with the substrate 2, and pushes down the mask 13, so that the load cell 76 as a load measuring means is used. It functions as a tension calculator that calculates the tension of the mask 13 based on the relationship between the axial load F of the squeegee lifting shaft 61 to be measured and the amount of depression δ at the center of the mask 13.

  In the storage unit 80a of the control device 80, when the mask 13 has a normal tension, the axis of the squeegee lifting shaft 61 measured when the central portion of the mask 13 is pushed down by a predetermined pushing amount δ0. A reference value F0 of the directional load F is stored, and the control device 80 determines that the axial load value F of the squeegee lifting shaft 61 measured when the mask 13 is actually pushed down by the prescribed depression amount δ0. If it is F0 or more, it is determined that the tension of the mask 13 is normal, and if it is below the reference value F0, it is determined that the tension of the mask 13 is abnormal.

  After calculating the tension of the mask 13 in step ST25, the control device 80 raises the squeegee 14 lowered in step ST23 to the original position (squeegee raising process shown in step ST26 of FIG. 9). Then, in the above manner, it is determined whether or not the tension of the mask 13 calculated in step ST25 is normal (determination step shown in step ST27 in FIG. 9).

  If the control device 80 determines in step ST27 that the calculated tension of the mask 13 is not normal (not normal), the control device 80 is provided on the base 11 after temporarily suspending the operation of the screen printing machine 1. In addition, a notification that the tension of the mask 13 is abnormal is given by image display via the display device 86 (FIG. 7) (notification step shown in step ST28 of FIG. 9). Upon receiving this notification, the operator OP replaces the mask 13 and operates the operation restart button 87 (FIG. 7) provided on the base 11, but the control device 80 receives the operation signal of the operation restart button 87. In determining whether or not the operation resume button 87 has been operated by the operator OP based on the output (determination step shown in step ST29 in FIG. 9), if it is determined that the operation resume button 87 has been operated by the operator OP, step Returning to ST22, the measurement of the tension of the mask 13 is performed again.

  On the other hand, when it is determined in step ST27 that the calculated tension of the mask 13 is normal, the control device 80 notifies the fact that the tension of the mask 13 is normal by image display via the display device 86. Then (notification process shown in step ST30 in FIG. 9), the process returns to the main routine.

  As a result, it is possible to prevent the defective substrate from being produced by performing screen printing while the tension of the mask 13 is in an abnormal state (the downward deflection is large).

  When the mask tension measuring step of step ST1 is completed by the above procedure, the control device 80 detects the substrate carrying conveyor from another device or the like (not shown) installed on the upstream side of the screen printing machine 1 by a detection unit (not shown). 25, when the substrate 2 is detected, the substrate carrying conveyor 25 and the conveyor unit 23 are operated in conjunction to carry the substrate 2 into the screen printer 1 (arrow B shown in FIG. 12A). Furthermore, when the detection means (not shown) detects that the substrate 2 into which the conveyor unit 23 is loaded has reached a predetermined conveyance stop position, the operation of the conveyor unit 23 is stopped and the substrate 2 is stopped (FIG. 12B). 8) A substrate carrying-in process shown in step ST2 of FIG.

  When the loading of the substrate 2 is completed, the control device 80 raises the lower receiving unit 24c (lower receiving unit support table 24b) with respect to the lifting table 22a while keeping the lifting table 22a in the lowered position with respect to the base table 21d. (The arrow C1 shown in FIG. 13 (a)), when the upper end of the lower receiving unit 24c comes into contact with the lower surface of the substrate 2 from below, the raising of the lower receiving unit 24c is stopped (FIG. 13 (a)). Both side portions of the substrate 2 on the conveyor portion 23 are clamped by the front and rear clamping members 24a (FIG. 13 (b), arrow D1 shown in the figure). The lower receiving unit 24c is further raised with respect to the lifting table 22a while the lifting table 22a is positioned at the lowered position with respect to the base table 21d, and the substrate 2 is pushed up by the lower receiving unit 24c (FIG. 14A). Arrow C2) shown in the figure. As a result, the substrate 2 is raised while sliding both ends in the Y-axis direction with respect to the clamp member 24a (the substrate 2 is separated upward from both the belt conveyors 23b of the conveyor unit 23), and the receiving unit 24c is moved to the lifting table 22a. When the upper surface of the substrate 2 is substantially at the same height as the upper surfaces of the clamp members 24a, the controller 80 stops the push-up of the lower receiving unit 24c. As a result, the substrate 2 is held by the substrate holding section 24 (FIG. 14A). The substrate holding step shown in step ST3 of FIG.

  After holding the substrate 2 by the substrate holder 24 as described above, the control device 80 controls the operation of the camera unit moving mechanism 84 (the X-axis stage 51 is moved in the Y-axis direction and the camera support stage is moved). 52 is moved in the X-axis direction), the first camera 15a is positioned immediately above the substrate-side positioning mark mk provided on the substrate 2, and the first camera 15a performs imaging of the substrate-side positioning mark mk. On the other hand, the second camera 15b is positioned immediately below the mask side positioning mark MK provided on the mask 13, and the second camera 15b is caused to image the mask side positioning mark MK. Then, the control device 80 grasps the position of the substrate 2 from the obtained image data of the substrate-side positioning mark mk, and grasps the position of the mask 13 from the obtained image data of the mask-side positioning mark MK. The horizontal movement unit 21 provided in the substrate holding / moving unit 12 is controlled to move the substrate holding unit 24 (and hence the substrate 2) in the horizontal plane direction, and the substrate side positioning mark mk and the mask side positioning mark MK are moved. The substrate 2 is positioned in the horizontal plane direction with respect to the mask 13 so as to face each other vertically (positioning step shown in step ST4 in FIG. 8).

  When the positioning of the substrate 2 and the mask 13 in the horizontal plane direction is finished, the control device 80 raises the lifting table 22a with respect to the base table 21d (arrow E1 shown in FIG. 14B), and the substrate 2 is covered. The mask 13 is brought into relative contact with the upper surface, which is the printing surface (FIG. 14B). The substrate / mask contact process shown in step ST5 of FIG. As a result, the pattern hole 13a of the mask 13 and the electrode 3 on the substrate 2 are aligned in the vertical direction.

  When the control device 80 brings the substrate 2 into contact with the mask 13, the operation of the screen printing machine 1 is temporarily interrupted, and the operator OP is prompted to supply the paste by displaying an image via the display device 86. When the operator OP visually checks the paste remaining on the mask 13, determines whether or not to supply (supplement) the paste based on the amount of the paste, and determines that the paste should be supplied. Then, the paste Pst is supplied onto the mask 13 by a separately prepared paste supply syringe 90 (FIG. 15A). Then, when the supply of the paste Pst is finished, the operation restart button 87 described above is operated. The operator OP operates the operation restart button 87 even when it is determined that the supply of the paste Pst is unnecessary.

  The control device 80 determines whether or not the operation resumption button 87 has been operated by the operator OP after step ST5 based on the output of the operation signal of the operation resumption button 87 (determination shown in step ST6 in FIG. 8). Step) When it is determined that the operation resuming button 87 is operated by the operator OP, the operation interruption of the screen printing machine 1 is canceled, and one of the two squeegees 14 is lowered to lower the lower end of the squeegee 14. Is brought into contact with the mask 13 in contact with the substrate 2 from above (squeegee contact step shown in step ST7 of FIG. 8). At this time, the squeegee 14 brought into contact with the mask 13 is the front squeegee 14 (the squeegee 14 on the left side in FIG. 15) when the squeegee base 60 is positioned above the front clamp member 24a. When 60 is positioned above the rear clamp member 24a, it is the rear squeegee 14 (the squeegee 14 on the right side in FIG. 15).

  When the squeegee 14 is lowered and brought into contact with the mask 13, the control device 80 controls the operation of the squeegee base moving mechanism 85, and the squeegee base 60 is placed in contact with the mask 13 from above ( That is, the squeegee lifting shaft 61 is moved relative to the mask 13 in the Y-axis direction (that is, in the horizontal plane direction) to slide the squeegee 14 on the mask 13, and the squeegee 14 enters the pattern hole 13 a of the mask 13. By filling the paste Pst, the paste Pst is transferred onto the electrode 3 of the substrate 2.

  The control device 80 measures the axial load of the squeegee lifting shaft 61 by the load cell 76 while moving the squeegee 14, and detects foreign matter on the substrate 2 based on the measured axial load of the squeegee lifting shaft 61. I do. That is, the control device 80 slides the squeegee 14 on the mask 13 by moving the squeegee lifting shaft 61 relative to the mask 13 in the Y axis direction (horizontal plane direction) with the squeegee 14 in contact with the mask 13. The axial load of the squeegee lifting shaft 61 is measured while moving the paste Pst on the mask 13 onto the substrate 2, and the foreign matter on the substrate 2 is detected based on the measured axial load of the squeegee lifting shaft 61. (Transfer / foreign matter detection step shown in step ST8 to step ST10 shown in FIG. 8).

  In this process, when the squeegee 14 is slid on the mask 13, the control device 80 detects foreign matter on the substrate 2 based on the axial load of the squeegee lifting shaft 61 measured by the load cell 76 as load measuring means. It functions as a foreign matter detection unit that detects.

  In the screen printing machine 1 according to the present embodiment, as shown in FIG. 14B, both the contact region R1 of the mask 13 with the substrate 2 and both ends of the contact region R1 in the moving direction (Y-axis direction) of the squeegee 13. The area including the non-contact area R2 (area of the upper surface of the clamp member 24a) with the substrate 2 of the mask 13 located in the section is defined as the squeegee movement area R0 on the mask 13, and the control device 80 is configured to control the squeegee movement area R0. The squeegee base 60 is moved so that the squeegee 14 slides in the Y-axis direction. For this reason, the squeegee 14 moves along a route from one non-contact region R2 to the other non-contact region R2 via the contact region R1.

  In the transfer / foreign object detection step, the control device 80 moves the squeegee base 60 rearward with the front squeegee 14 in contact with the upper surface area of the front clamp member 24a. Slides backward on the mask 13 so that the paste Pst is raked behind the mask 13 on the contact region R1 (arrow F1 shown in FIG. 15B). On the other hand, for the rear squeegee 14, the control device 80 moves the squeegee base 60 forward with the rear squeegee 14 in contact with the upper surface area of the rear clamp member 24a, and the squeegee 14 moves over the mask 13. By sliding forward, the paste Pst is scraped to the front of the mask 13 on the contact region R1 (arrow F2 shown in FIG. 15C). As a result, the paste Pst is transferred onto the electrode 3 of the substrate 2 through the pattern hole 13 a of the mask 13.

  While the control device 80 slides the squeegee 14 on the mask 13 as described above, the axial load (compressive load) of the squeegee lifting shaft 61 measured by the load cell 76 is stored in the storage unit 80a. It is determined whether or not the threshold is exceeded (determination step shown in step ST9 in FIG. 8). When the axial load of the squeegee lifting shaft 61 to be measured exceeds the threshold value, foreign matter such as dust (including the upper substrate 2 in the case of flowing two substrates as will be described later) on the substrate 2. In order to protect the screen printing machine 1 and the substrate 2, the screen printing operation by the screen printing machine 1 is stopped (screen printing operation stop process shown in step ST11 of FIG. 8).

  Specifically, as shown in FIG. 16, the control device 80 slides the squeegee 14 on the contact region R1 of the mask 13 with the substrate 2 (arrow G1 shown in FIGS. 16A and 16B). When the measured value of the axial load (compressive load) of the squeegee lifting shaft 61 is P which is equal to or less than the threshold value (FIG. 16A), the measured value of the axial load of the squeegee lifting shaft 61 is P + ΔP. When the value P + ΔP exceeds the threshold value, it is determined that there is a foreign substance Q on the substrate 2 (see FIG. 16B). As a result, the squeegee 14 does not get over the foreign matter Q and travel on the mask 13, and the squeegee 14 is pushed upward by the foreign matter Q, and an excessive pressing force acts on the substrate 2 and the substrate 2 is damaged. Is prevented. Further, since the screen printing is not continued with the foreign substance Q on the substrate 2, the inconvenience that the substrate 2 with poor printing is produced can be prevented.

  In addition, as shown in FIG. 17, the control device 80 has a squeegee in a region from the non-contact region R2 with the substrate 2 to the contact region R1 with the substrate 2 (that is, in a region straddling the end of the substrate 2). When the measured value of the axial load (compression load) of the squeegee lifting shaft 61 when sliding 14 is slid (arrow G2 shown in FIGS. 17A and 17B) is P which is equal to or less than the threshold value ( 17 (a)), when the squeegee 14 tries to enter the contact region R1 of the mask 13 with the substrate 2, it is detected that the squeegee 14 has changed to P + ΔP exceeding the threshold value (FIG. 17 (b)). When a foreign object is detected at the end, it is determined that a plurality of substrates 2 are stacked (a state where two substrates are flown), and the screen printing operation is stopped in step ST11, and the display device 86 is displayed. Through The image display has to inform the user that the state of the flowing two substrates occurs the operator OP. For this reason, it is possible to prevent the situation where the substrate 2 itself is wasted by performing screen printing while the two substrates are being flowed.

  When the control device 80 detects that the squeegee 14 has reached the upper surface region of the other clamp member 24a from the upper surface region of the one clamp member 24a and the transfer of the paste Pst has been completed, the movement of the squeegee 14 (of the squeegee base 60). 8 is stopped (squeegee movement stopping step shown in step ST12 of FIG. 8), and the squeegee lifting shaft 61 is raised with respect to the squeegee base 60 to separate the squeegee 14 from the mask 13 (squeegee separation step shown in step ST13 of FIG. 8). ). Then, with the squeegee 14 separated from the mask 13, the amount of paste Pst adhering to the squeegee 14 (adhering paste amount) is measured based on the axial load of the squeegee lifting shaft 61 measured by the load cell 76. This is performed (attached paste amount measuring step shown in step ST14 of FIG. 8).

  In the adhesion paste amount measuring step in step ST14, the control device 80 first loads the axial loads (two axial squeegee shafts 61) by the load cells 76 corresponding to the two squeegees 14 raised relative to the mask 13, respectively. (Tensile load) is measured (load measurement step shown in step ST31 of FIG. 10). Based on the measured axial load of each squeegee lifting shaft 61, the amount of paste attached to the squeegee 14 is calculated (paste amount calculating step shown in step ST32 of FIG. 10). At this time, after transferring the paste Pst to the substrate 2, the control device 80 raises the squeegee lifting shaft 61 with respect to the mask 13, and the squeegee 14 is separated from the mask 13 and measured by the load cell 76 as a load measuring means. It functions as an attached paste amount calculating means for calculating the amount of paste attached to the squeegee 14 based on the axial load of the squeegee lifting shaft 61.

  When the control device 80 calculates the paste amount attached to the squeegee 14 as described above, the calculated attached paste amount (total amount of attached paste amounts to the two squeegees 14) is stored in the storage unit 80a. It is determined whether it is below the threshold value (determination step shown in step ST33 of FIG. 10). When the control device 80 determines that the amount of the paste paste is not less than the threshold value (exceeds the threshold value), the operation of the screen printing machine 1 is temporarily interrupted, and then the squeegee is displayed by image display via the display device 86. 14 is notified that the paste Pst attached to 14 needs to be peeled off (notification process shown in step ST34 in FIG. 10).

  For example, when the measured value of the axial load (compression load) of the squeegee lifting shaft 61 when the squeegee 14 is separated from the mask 13 is W when the paste Pst is not attached to the squeegee 14 ( 18 (a)), when the paste Pst is attached to the squeegee 14, the measured value of the axial load of the squeegee lifting shaft 61 increases by the weight ΔW of the paste Pst and becomes W + ΔW (FIG. 18 ( b)) When the value W + ΔW exceeds the threshold value, the control device 80 determines that the paste Pst attached to the squeegee 14 needs to be peeled off.

  When the operator OP is notified that the paste Pst attached to the display device 86 needs to be peeled off, the operator OP performs an operation of removing the paste Pst attached to the squeegee 14 and operates the operation restart button 87. The control device 80 determines whether or not the operation restart button 87 has been operated by the operator OP based on the output of the operation signal from the operation restart button 87 (determination step shown in step ST35 in FIG. 10). When it is determined that the operation restart button 87 has been operated, the process returns to step ST31 and the measurement of the amount of attached paste is performed again. As a result, the operator OP can accurately determine the amount of remaining paste on the mask 13, and the paste Pst should be additionally supplied at the time of supplying the paste after step ST5 for the substrate 2 to be screen-printed next. Appropriate judgment can be made.

  On the other hand, if the control device 80 determines in step ST33 that the measured amount of attached paste is less than or equal to the threshold value, it is not necessary to peel off the paste attached to the squeegee 14 by displaying an image via the display device 86. After notifying that there is (notification process shown in step ST36 of FIG. 10), the process returns to the main routine.

  When the control device 80 measures the amount of adhered paste by the above procedure, the control table 80 lowers the elevating table 22a relative to the base table 21d (arrow E2 shown in FIG. 19A), and separates the substrate 2 from the mask 13. (FIG. 19A). As a result, plate separation is performed, and the paste Pst is printed on the electrode 3 of the substrate 2 (plate separation step shown in step ST15 of FIG. 8).

  When the printing of the paste Pst on the substrate 2 is completed, the control device 80 operates the clamp member 24a to release the clamp of the substrate 2 (arrow D2 shown in FIG. 19B), and then the receiving unit 24c. (The receiving unit support table 24b) is lowered with respect to the lifting table 22a (arrow C3 shown in FIG. 19C), and the substrate 2 is lowered onto the conveyor portion 23 (FIG. 19C). Thereby, the holding of the substrate 2 by the substrate holding unit 24 is released (substrate holding releasing step shown in step ST16 of FIG. 8).

  When the holding of the substrate 2 is released, the control device 80 operates the horizontal moving unit 21 provided in the substrate holding and moving unit 12 to adjust the position of the conveyor unit 23 with respect to the substrate carry-out conveyor 26, and then the conveyor unit 23 and the substrate The carry-out conveyor 26 is operated in conjunction, the substrate 2 on the conveyor unit 23 is transferred to the substrate carry-out conveyor 26, and the substrate 2 is directly carried out of the screen printing machine 1 (substrate carry-out process shown in step ST17 in FIG. 8).

  After carrying out the substrate 2, the control device 80 determines whether there is another substrate 2 to be screen printed (determination step shown in step ST18 in FIG. 8). As a result, if there is another substrate 2 to be screen-printed, the process returns to step ST2 to carry in a new substrate 2, and if there is no other substrate 2 to be screen-printed, a series of screen printing operations. Exit.

  As described above, in the screen printing machine 1 (and the attached paste amount measuring method in the screen printing machine 1) according to the present embodiment, after the paste Pst is transferred to the substrate 2, the squeegee lifting shaft 61 is used as the mask 13. On the other hand, the amount of paste adhered to the squeegee 14 is calculated (measured) based on the axial load (tensile load) of the squeegee lifting shaft 61 measured with the squeegee 14 being separated from the mask 13. If the amount of paste adhering to the squeegee 14 is large, appropriate measures such as peeling off the paste Pst from the squeegee 14 can be taken to accurately determine the amount of paste remaining on the mask 13. It is possible to prevent the paste Pst from being supplied more than necessary.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above. For example, in the above-described embodiment, the squeegee lifting shaft 61 is composed of a ball screw that moves up and down with respect to the squeegee base 60, but a piston that can project and retract below an air cylinder attached to the squeegee base 60. It may consist of a rod. In the above-described embodiment, two squeegees 14 are provided. However, two squeegees 14 are not necessarily provided, and only one squeegee 14 may be provided.

  In the above-described embodiment, the strain gauge type attached to the elastic body 75 interposed between the squeegee lifting shaft 61 and the squeegee 14 is used as a load measuring means for measuring the axial load of the squeegee lifting shaft 61. However, the configuration of the load measuring means is not particularly limited. However, when the load measuring means is composed of the load cell 76 attached to the elastic body 75 interposed between the squeegee lifting shaft 61 and the squeegee 14, the axial load of the squeegee lifting shaft 61 is very inexpensive. It is possible to measure with this, and there is an advantage that it can greatly contribute to cost reduction.

  Further, in the above-described embodiment, the attached paste amount measuring step of step ST15 for calculating the amount of paste attached to the squeegee 14 based on the measured axial load of the squeegee lifting shaft 61 raises the squeegee 14 and the mask 13 Step ST15 is performed immediately after the squeegee separation step of step ST14. The adhesion paste amount measurement step of step ST15 is step ST8 for the next loaded substrate 2 after the squeegee separation step of step ST14. This may be performed before the squeegee contact process. Considering that the paste Pst adhering to the squeegee 14 hangs down from the squeegee 14 due to its own weight and returns onto the mask 13, the adhering paste amount measuring step in step ST15 is the next substrate 2 carried in for screen printing. It is performed immediately before the step of bringing the squeegee 14 into contact with the mask 13 brought into contact with the mask (the squeegee contact step of step ST8), and the amount of paste adhered is outside the specified range in steps ST33 to ST34. This is preferable in terms of work efficiency.

  In the above-described embodiment, when the control device 80 determines that the paste Pst adhering to the squeegee 14 exceeds the threshold in the determination step of step ST33, the control device 80 notifies the operator OP of that fact and notifies the operator OP. The operator OP that peeled off the paste Pst from the squeegee 14 detects that the operation resume button 87 has been operated, and re-executes the measurement of the amount of paste. However, instead of such a configuration, the control device 80 that has detected that the paste Pst attached to the squeegee 14 has exceeded the threshold value moves the squeegee 14 up and down or left and right to thereby paste the paste Pst from the squeegee 14. After peeling off and removing for a certain period of time, re-execution of the measurement of the amount of paste is automatically opened. It may be.

  A screen printer capable of accurately determining the amount of paste remaining on the mask and preventing the replenishment of excessive paste on the mask and a method for measuring the amount of paste adhered to the screen printer are provided. To do.

DESCRIPTION OF SYMBOLS 1 Screen printer 2 Board | substrate 13 Mask 14 Squeegee 61 Squeegee raising / lowering shaft 75 Elastic body 76 Load cell (load measuring means)
80 Control device (adhesive paste amount calculating means)
Pst paste

Claims (5)

A mask in contact with the upper surface of the substrate;
A squeegee lifting shaft that is lifted and lowered relative to the mask;
Paste that is attached to the lower end of the squeegee lifting shaft and slides on the mask when the squeegee lifting shaft is moved relative to the mask in the horizontal plane while in contact with the mask from above. A squeegee that transfers the image to the substrate,
Load measuring means for measuring the axial load of the squeegee lifting shaft;
After the paste is transferred to the substrate, the squeegee lifting shaft is lifted with respect to the mask, and the paste attached to the squeegee based on the axial load of the squeegee lifting shaft measured by the load measuring means with the squeegee separated from the mask A screen printing machine comprising an attached paste amount calculating means for calculating the amount.   2. The screen printing machine according to claim 1, wherein the load measuring means includes a load cell attached to an elastic body interposed between a squeegee lifting shaft and a squeegee. Contacting the mask with the top surface of the substrate;
A step of bringing the squeegee attached to the lower end of the squeegee lifting shaft that is raised and lowered relative to the mask into contact with the mask from above;
A process in which the paste supplied on the mask is transferred to the substrate by sliding the squeegee up and down on the mask relative to the mask in a horizontal plane direction with the squeegee in contact with the mask. ,
After transferring the paste to the substrate, measuring the axial load of the squeegee lifting shaft while raising the squeegee lifting shaft with respect to the mask and separating the squeegee from the mask;
And a step of calculating the amount of paste adhering to the squeegee based on the measured axial load of the squeegee lifting shaft.   4. An adhesion paste amount measurement in a screen printing machine according to claim 3, wherein an axial load of the squeegee lifting shaft is measured by a load cell attached to an elastic body interposed between the squeegee lifting shaft and the squeegee. Method.   After transferring the paste to the substrate, the step of measuring the axial load of the squeegee lifting shaft in a state where the squeegee lifting shaft is lifted with respect to the mask and the squeegee is separated from the mask, after the paste is transferred to the substrate, 5. The method for measuring an amount of attached paste in a screen printing machine according to claim 3, wherein the method is performed immediately before the step of bringing a squeegee into contact with a mask that is in contact with a substrate on which screen printing is performed. .

Images