JP5488272B2 - Screen printer and method for detecting foreign matter in screen printer - Google Patents

Description

The present invention relates to a screen printer that prints a paste on a substrate through a mask and a foreign matter detection method in the screen printer.

  A screen printing machine that prints a paste such as a solder paste on a board, after bringing the mask into contact with the substrate so that the pattern hole is vertically aligned with the mask on which the pattern hole corresponding to the electrode of the board is formed, By sliding the squeegee on the mask supplied with the paste 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 squeegee is attached to the lower end of the squeegee lifting shaft that moves up and down with respect to the squeegee base that is moved in the horizontal plane above the mask. When there is a foreign object, the squeegee is pushed up by the foreign object, so that the axial load (compressive load) of the squeegee lifting shaft increases and a large pressing force acts on the substrate, which may damage the substrate. For this reason, conventionally, when a load cell as a load detecting means for detecting the axial load of the squeegee lifting shaft is provided on the elastic body interposed between the squeegee lifting shaft and the squeegee, the squeegee is slid on the mask. There is known a technique in which foreign matter on a substrate is detected based on the amount of change in the axial load of the squeegee lifting shaft detected in (1).

JP 2000-263754 A

  However, the axial load of the squeegee lifting shaft detected by the load detecting means is an elastic body to which the load detecting means is attached when the pressing force (so-called printing pressure) of the squeegee against the mask is too small or too large. There is a problem that foreign matter detection may not be performed with accuracy due to absorption by the elastic force of the lens and the elastic force of the squeegee.

  Accordingly, an object of the present invention is to provide a screen printing machine and a foreign matter detection method in a screen printing machine that can accurately inspect foreign matter on a substrate regardless of the magnitude of printing pressure.

The screen printing machine according to claim 1, a mask that is in contact with the upper surface of the substrate, a squeegee base that is provided above the mask and moves in a horizontal plane, and a squeegee lifting shaft that is lifted and lowered relative to the squeegee base. Attached to the lower end of the squeegee lifting shaft, the squeegee base is moved in the horizontal plane while in contact with the mask from above, and the paste supplied on the mask is transferred to the substrate. A squeegee to be moved, a load detecting means for detecting an axial load of the squeegee lifting shaft, a position detecting means for detecting a vertical position of the squeegee with respect to the squeegee base, and a load when the squeegee is slid on the mask. The variation amount of the axial load of the squeegee lifting shaft is obtained from the axial load of the squeegee lifting shaft detected by the detecting means, or by the position detecting means. And a foreign object detecting means from the vertical position relative to the squeegee base squeegees detected asking the variation of vertical position relative to the squeegee base squeegees to detect a foreign substance on the substrate, the foreign matter detection means, the squeegee sliding When the axial load of the squeegee lifting shaft detected by the load detection means at the start of operation is within the appropriate load range, foreign matter on the substrate is detected based on the amount of variation in the axial load of the squeegee lifting shaft , When the axial load of the squeegee lifting shaft detected by the load detecting means at the start of the sliding operation of the squeegee is not within the appropriate load range, the squeegee on the substrate based on the amount of change in the vertical position relative to the squeegee base. for the detection of foreign matter.

The foreign matter detection method in the screen printing machine according to claim 2 is attached to a lower end of a squeegee lifting shaft that is lifted and lowered with respect to a squeegee base provided above the mask and a step of bringing the mask into contact with the upper surface of the substrate. The process of bringing the squeegee into contact with the mask from above, and moving the squeegee base in the horizontal plane with the squeegee in contact with the mask, sliding the squeegee on the mask and transferring the paste on the mask to the substrate By detecting the axial load of the squeegee lifting shaft or detecting the vertical position of the squeegee with respect to the squeegee base, the amount of variation in the axial load of the squeegee lifting shaft or the vertical position of the squeegee with respect to the squeegee base is detected. and performing detection of foreign matter on the substrate to determine the amount, the load detecting means at the start of the sliding movement of the squeegee And a step of axial load of the squeegee elevating shaft to be detected and determines whether it is within the proper load range I, when axial load detected squeegee elevating shaft were within the appropriate load range performs detection of foreign matter on the substrate based on the variation amount of the axial load of the squeegee elevating shaft when the axial load of the detected squeegee elevating shaft was not within the proper load range, for squeegee base squeegees the detection of foreign matter on the substrate based on the variation amount of the vertical position.

In the present invention, in addition to the load detecting means for detecting an axial load of the squeegee elevating shaft, a position detecting means for detecting a vertical position relative to the squeegee-based squeegee is provided with, at the start of the sliding movement of the squeegee When the axial load of the squeegee lifting shaft detected by the load detection means is within the appropriate load range, foreign matter on the board is detected based on the amount of variation in the axial load of the squeegee lifting shaft, and the squeegee slides When the axial load of the squeegee lifting shaft detected by the load detection means at the start of the operation is not within the appropriate load range, foreign matter on the substrate is detected based on the amount of fluctuation of the vertical position of the squeegee with respect to the squeegee base. Runode have been way, regardless of the size of the printing pressure with respect to the mask of the squeegee, the inspection of foreign substances on the substrate can be performed with high accuracy.

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 (A) (b) Side view of the squeegee with which the screen printing machine in one embodiment of this invention is provided. (A) A graph showing the axial load P of the squeegee lifting axis detected by the load cell included in the screen printing machine according to the embodiment of the present invention on the vertical axis and the time t on the horizontal axis. The graph which expressed the vertical direction position T with respect to the squeegee base of the squeegee detected by the linear scale included in the screen printing machine in the embodiment as the vertical axis and the time t as the horizontal axis. The graph explaining the suitable load range of the screen printer in one embodiment of the present invention The flowchart of the main routine which shows the execution 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 execution procedure of the screen printing operation which the screen printer in one embodiment of this invention performs (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) 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) Side view of the squeegee with which the screen printing machine in one embodiment of this invention is provided. (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 performed 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 FIG. 1 and FIG. 2, both ends of a squeegee base 60 extending in the X-axis direction are supported by a pair of portal frames 28, and the squeegee base 60 can reciprocate in the Y-axis direction along the portal frame 28. It has become. 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, two squeegee lifting shafts 61 made of ball screws are 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 elevating shaft 61 and the nut member 63 are screwed together, and the squeegee elevating shaft 61 extends vertically (through a loose fit) through a ring-shaped driven pulley 64 fixed to the upper portion of the nut member 63. Yes.

  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 aligned with its vertical center axis via the transmission belt 74 (this axis coincides with the vertical center axis of the squeegee lifting shaft 61. ) And the nut member 63 rotates together with the driven pulley 64, so that the squeegee lifting shaft 61 moves up and down with respect to the nut member 63 (that is, with respect to 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 of the mask 13 and the squeegee base 60 in the vertical direction does not change, the squeegee lifting shaft 61 and the squeegee 14 are raised and lowered 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 as a load detecting means 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 measured by the load cell 76. It is detected as an axial load.

  As shown in FIGS. 5 and 6, a linear scale as position detecting means for detecting the vertical position of the squeegee 14 with respect to the squeegee base 60 (and hence with respect to the mask 13) is provided between the squeegee 14 and the squeegee base 60. 77 is provided. The linear scale 77 extends downward from the squeegee base 60, has a large number of lattice scales L (see the enlarged view shown in FIG. 5) arranged at equal intervals in the vertical direction, and a light receiving element (not shown). It has a built-in glass scale part 77a and a light emitting element part 77c that is supported by a frame part 77b attached to the upper surface of the squeegee holder attaching member 65 and faces the glass scale part 77a.

  In this linear scale 77, the vertical position of the moving side member provided with the light emitting element portion 77c with respect to the fixed side member based on the interference fringes generated when the light emitted from the light emitting element portion 77c passes through the lattice scale L. That is, the vertical position of the squeegee 14 with respect to the squeegee base 60 is detected. Then, from the vertical position of the squeegee 14 relative to the squeegee base 60 determined by the linear scale 77, the amount of variation in the vertical position of the squeegee 14 relative to the squeegee base 60 is determined.

  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 image the substrate-side positioning mark mk of the substrate 2 held by the substrate holding unit 24 of the substrate holding and moving unit 12, and the second camera 15a The camera 15 b is controlled by the control device 80 and images 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). Further, the value of the axial load of the squeegee lifting shaft 61 detected by two load cells 76 provided corresponding to each squeegee 14 and the two linear scales 77 provided corresponding to each squeegee 14 are detected. The value of the vertical position of the squeegee 14 relative to the squeegee base 60 is input to the control device 80 (FIG. 7).

  As shown in FIGS. 8A and 8B, when the squeegee 14 is moved (slid) on the mask 13 to transfer the paste Pst to the substrate 2, the axial load P ( The pressing force of the squeegee 14 against the mask 13 is held at a value corresponding to the printing pressure Pm, and an average value corresponding to the printing pressure Pm is obtained from the load cell 76 corresponding to the squeegee 14 in contact with the mask 13. Although output, when the squeegee 14 slides on the mask 13 (arrow A shown in the figure), the squeegee 14 rides on the foreign substance Q such as dust existing on the substrate 2 through the mask 13. Since the squeegee 14 is pushed upward by the foreign matter Q and moves to the squeegee base 60 side, the value of the axial load P of the squeegee lifting shaft 61 detected by the load cell 76 fluctuates (rises).Therefore, the axial load P of the squeegee lifting shaft 61 output from the load cell 76 is monitored, and the fluctuation amount ΔP from the printing pressure Pm of the axial load P of the squeegee lifting shaft 61 obtained thereby (FIG. 8 (b) and FIG. 9A shows a threshold value ΔP1 (hereinafter referred to as “load fluctuation amount corresponding threshold value ΔP1”) that is predetermined as a lower limit value of the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 that can detect the foreign matter Q with high accuracy. It is possible to determine that the foreign matter Q exists on the substrate 2. Here, FIG. 9A is a graph showing the axial load P of the squeegee lifting shaft 61 detected by the load cell 76 as the vertical axis and the time t as the horizontal axis.

  Further, as shown in FIGS. 8A and 8B, when the squeegee 14 is moved (slid) on the mask 13 to transfer the paste Pst to the substrate 2, the squeegee 14 from the squeegee base 60 is transferred. The vertical position T is held at a printing pressure corresponding value Tm corresponding to the printing pressure Pm which is the axial load P (the pressing force of the squeegee 14 against the mask 13) of the squeegee lifting shaft 61 at that time. The printing pressure corresponding value Tm is output on the average, but when the squeegee 14 slides on the mask 13 (arrow A shown in the figure), the squeegee 14 has foreign matter on the substrate 2 through the mask 13. When riding on Q, the squeegee 14 is pushed upward by the foreign matter Q and moves toward the squeegee base 60, so the squeegee base 6 of the squeegee 14 detected by the linear scale 77. The value of vertical position T relative varies (decreases).

  Accordingly, the vertical position T of the squeegee 14 with respect to the squeegee base 60 output from the linear scale 77 is monitored, and the variation ΔT from the printing pressure corresponding value Tm of the vertical position T with respect to the squeegee base 60 of FIG. When b) and FIG. 9B exceed a predetermined threshold value ΔT1 (hereinafter, referred to as “vertical position variation corresponding threshold value ΔT1”), it is determined that the foreign matter Q exists on the substrate 2. Can do. Here, FIG. 9B is a graph showing the vertical position T of the squeegee 14 detected by the linear scale 77 with respect to the squeegee base 60, and the time t as the horizontal axis.

  It should be noted that the above two threshold values ΔP1 and ΔT1 are previously tested to determine what values are obtained when the squeegee 14 rides on the foreign matter Q on the substrate 2 when the squeegee 14 is slid on the mask 13. It is set by checking with etc.

  Here, the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 obtained when the squeegee 14 rides on the (identical) foreign matter Q changes in accordance with the printing pressure Pm of the squeegee 14 at that time, and the printing pressure It has been found that the variation ΔP of the axial load P of the squeegee lifting shaft 61 is small and difficult to detect whether Pm is smaller or larger than a certain range of load. When the printing pressure Pm is too small, a part of the axial load P of the squeegee lifting shaft 61 is absorbed by the elastic force of the elastic body 75 to which the load cell 76 is attached, and the printing pressure Pm is too large. This is considered to be because a part of the axial load P of the squeegee lifting shaft 61 is absorbed by the elastic force of the squeegee 14.

  For this reason, in the screen printing machine 1 according to the present embodiment, the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 when the squeegee 14 is slid on the mask 13 is the elasticity to which the load cell 76 is attached. The load range in which the foreign object Q can be detected accurately without being absorbed by the elastic force of the body 75 and the squeegee 14 is defined as the appropriate load range Rg (FIG. 10). Then, it is determined whether or not the printing pressure Pm detected by the load cell 76 at the start of sliding on the mask 13 of the squeegee 14 is within the predetermined appropriate load range Rg. The printing pressure Pm is determined to be within the appropriate load range Rg. The foreign matter is detected based on the variation ΔP of the axial load P obtained from the axial load P of the squeegee lifting shaft 61 detected by the load cell 76, and the printing pressure Pm detected by the load cell 76 is obtained. When the load is not within the appropriate load range Rg, the foreign matter is detected based on the fluctuation amount ΔT of the vertical position T obtained from the vertical position T of the squeegee 14 with respect to the squeegee base 60 detected by the linear scale 77. . In addition, the said appropriate load range Rg becomes a range of about 50-150N, when the allowance from the squeegee holder 70 of the metal squeegee main body 71 is 13 mm, for example.

  In FIG. 7, the control device 80 includes a fluctuation amount calculation unit 80 a, a storage unit 80 b, and a determination unit 80 c. The fluctuation amount calculation unit 80a monitors the axial load P of the squeegee lifting shaft 61 detected by the load cell 76 when the squeegee 14 slides on the mask 13, and obtains the fluctuation amount ΔP. The vertical position T of the squeegee 14 (squeegee 14 sliding on the mask 13) detected by 77 with respect to the squeegee base 60 is monitored to determine the variation ΔT.

  The storage unit 80b stores data of the above-described two threshold values (the load fluctuation amount correspondence threshold value ΔP1 and the vertical position fluctuation amount correspondence threshold value ΔT1) and the appropriate load range Rg.

  The determination unit 80c of the control device 80 determines that the axial load P (that is, the printing pressure Pm) of the squeegee lifting shaft 61 detected by the load cell 76 at the start of the sliding operation of the squeegee 14 on the mask 13 is stored in the storage unit 80b. It is determined whether or not the load is within the stored appropriate load range Rg. When the printing pressure Pm detected by the load cell 76 at the start of sliding on the mask 13 of the squeegee 14 is within the appropriate load range Rg, the fluctuation amount calculation unit 80a during the sliding of the squeegee 14 with respect to the mask 13 causes The calculated fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 is compared with the load fluctuation amount corresponding threshold value ΔP1 stored in the storage unit 80b, and the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 is the load fluctuation. When the amount-corresponding threshold ΔP1 is exceeded, it is determined that the foreign matter Q is present on the substrate 2.

  On the other hand, when the printing pressure Pm detected by the load cell 76 at the start of sliding of the squeegee 14 on the mask 13 is not within the appropriate load range Rg, the fluctuation amount calculation unit 80a during the sliding of the squeegee 14 with respect to the mask 13 The calculated fluctuation amount ΔT of the vertical position T of the squeegee 14 relative to the squeegee base 60 is compared with the vertical position fluctuation amount corresponding threshold value ΔT1 stored in the storage unit 80b, and the vertical position T of the squeegee 14 relative to the squeegee base 60 is compared. When the fluctuation amount ΔT exceeds the vertical position fluctuation amount correspondence threshold ΔT1, it is determined that the foreign matter Q is present on the substrate 2.

  Next, the execution procedure of the screen printing operation by the screen printer 1 will be described with reference to the flowcharts of FIGS. 11 and 12 and the explanatory diagrams of FIGS. Here, FIG. 11 is a flowchart of a main routine of the operation of the screen printer 1, and FIG. 12 is a flowchart of a subroutine in the main routine.

  In the screen printer 1 according to the present embodiment, the control device 80 causes the substrate 2 to be transferred to the substrate carry-in conveyor 25 from another device or the like (not shown) installed on the upstream side of the screen printer 1 by detection means (not shown). Is detected, the substrate carry-in conveyor 25 and the conveyor unit 23 are operated in conjunction to carry the substrate 2 into the screen printing machine 1 (arrow B shown in FIG. 13 (a)). When the detection means detects that the substrate 2 carried in by the conveyor unit 23 has reached a predetermined conveyance stop position, the operation of the conveyor unit 23 is stopped and the substrate 2 is stopped (FIG. 13B). Step ST1 substrate loading step shown in 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. 14 (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. 14 (a)). Both side portions of the substrate 2 on the conveyor portion 23 are clamped by the front and rear clamp members 24a (FIG. 14B, arrow D1 shown in the figure).

  After clamping both ends of the substrate 2 with the front and rear clamping members 24a, the control device 80 further raises the lower receiving unit 24c with respect to the lifting table 22a while keeping the lifting table 22a in the lowered position with respect to the base table 21d. Then, the substrate 2 is pushed up by the receiving unit 24c (FIG. 15 (a), 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 unit 24 (FIG. 15A). The substrate holding step of step ST2 shown in FIG.

  When the substrate holding process is completed, the control device 80 controls the operation of the camera unit moving mechanism 84 (moves the X-axis stage 51 in the Y-axis direction and moves the camera support stage 52 in the X-axis direction). The first camera 15a is positioned immediately above the board-side positioning mark mk provided on the board 2, and the board-side positioning mark mk is imaged by the first camera 15a, and the position of the board 2 is determined from the image data. While grasping (FIG. 15 (b)), 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. The position of the mask 13 is grasped from the image data (FIG. 16A). Then, the control device 80 controls the operation of the horizontal moving unit 21 included in the substrate holding / moving unit 12 based on the grasped position of the substrate 2 and the position of the mask 13 to control the substrate holding unit 24 (and hence the substrate 2). The substrate 2 is moved in the horizontal plane so that the substrate-side positioning mark mk and the mask-side positioning mark MK are vertically opposed to each other, and the substrate 2 is positioned in the horizontal plane with respect to the mask 13 (step ST3 shown in FIG. 11). Positioning step).

  When the positioning step is completed, the control device 80 raises the lifting table 22a with respect to the base table 21d (arrow E1 shown in FIG. 16B), and puts the mask 13 on the upper surface which is the printing surface of the substrate 2. They are brought into relative contact with each other (FIG. 16B). The substrate / mask contact process in step ST4 shown in 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 then the operator displays the image via the display device 86 (FIG. 7) provided in the screen printing machine 1. Encourage OP to supply paste. 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 the paste supply syringe 90 (FIG. 17A) prepared separately. When the supply of the paste Pst is finished, the operation restart button 87 (FIG. 7) provided in the screen printer 1 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 the step ST4 based on the output of the operation signal of the operation resumption button 87 (first step ST5 shown in FIG. 11). 1 determination step), when it is determined that the operation restart button 87 has been operated by the operator OP, the operation interruption of the screen printing machine 1 is canceled, one of the two squeegees 14 is lowered, and the squeegee 14 is moved down. Is brought into contact with the mask 13 in contact with the substrate 2 from above (squeegee contact step of step ST6 shown in FIG. 11). In this case, the squeegee 14 to be brought into contact with the mask 13 is the front squeegee 14 (the squeegee 14 on the left side in FIG. 17) 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. 17).

  When the squeegee 14 is lowered and brought into contact with the mask 13, the control device 80 transfers the paste Pst on the mask 13 to the substrate 2 (steps ST7 shown in FIG. 11 and subroutines shown in FIG. 12). ). In the paste transfer process, the control device 80 first controls the operation of the squeegee base moving mechanism 85 so that the squeegee 14 is in contact with the mask 13 from above and the squeegee 14 on the side of the squeegee 14 that is in contact with the mask 13. The printing pressure Pm is detected based on the axial load P of the squeegee lifting shaft 61 output from the load cell 76 (printing pressure detection step in step ST701 shown in FIG. 12), and the detected printing pressure Pm is within a predetermined range (appropriate load). It is determined whether it is within the range (Rg) (second determination step of step ST702 shown in FIG. 12). As a result, if the detected printing pressure Pm is within the appropriate load range Rg, the control device 80 substitutes “0” for the flag F in executing the algorithm (flag substitution step in step ST703 shown in FIG. 12). When the detected printing pressure Pm is not within the appropriate load range Rg, “1” is substituted for the flag F (flag substitution step of step ST704 shown in FIG. 12).

  When the printing pressure detection process in step ST702 and the flag substitution process in step ST703 or step ST704 are completed, the control device 80 moves the squeegee base 60 (that is, the squeegee lifting shaft 61) in the Y-axis direction (that is, in the horizontal plane direction). As a result, the squeegee 14 is slid on the mask 13 (step ST705 squeegee moving step shown in FIG. 12), and the paste Pst is filled in the pattern hole 13a of the mask 13 with the squeegee 14 to thereby paste the paste Pst onto the substrate 2. The electrode 3 is transferred.

  In the squeegee moving 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. By sliding backward on the mask 13, the paste Pst is scraped to the rear of the mask 13 (arrow F1 shown in FIG. 17B). 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 raked forward of the mask 13 (arrow F2 shown in FIG. 17C). 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.

  In the screen printer 1 according to the present embodiment, as shown in FIG. 16B, the contact area (substrate contact area R1) of the mask 13 with the substrate 2 and the moving direction of the squeegee 14 in the substrate contact area R1 ( A region including a contact region (clamp member contact region R2) with the clamp member 24a located at both ends in the Y-axis direction is defined as a squeegee movement region R0 on the mask 13, and the control device 80 controls the squeegee movement region 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 path from the one clamp member contact region R2 through the substrate contact region R1 to the other clamp member contact region R2.

  The control device 80 determines the flag F while moving the squeegee 14 in the above-described squeegee moving process (flag determining process in step ST706 shown in FIG. 12). When the determined flag F is “0” (that is, when the printing pressure Pm is within the appropriate load range Rg), the axial load P of the squeegee lifting shaft 61 obtained from the output from the load cell 76 is obtained. The foreign matter Q is detected by determining whether or not the fluctuation amount ΔP is equal to or less than a threshold value (load fluctuation amount corresponding threshold value ΔP1) (foreign matter detection step based on the load fluctuation amount in step ST707 shown in FIG. 12). When the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 determined by the output from the load cell 76 is within the load fluctuation amount corresponding threshold value ΔP1, the movement of the squeegee 14 within the clamp member contact region R2 is completed. It is determined whether or not the point has been reached (third determination step in step ST708 shown in FIG. 12). If the squeegee 14 has not reached the movement end point, the process returns to step ST705 to continue sliding the squeegee 14 on the mask 13, and if the squeegee 14 has reached the movement end point. The movement of the squeegee 14 is stopped (step S709 squeegee movement stopping step shown in FIG. 12), and the process returns to the main routine.

  On the other hand, the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 obtained by the output from the load cell 76 in the foreign object detection step based on the load fluctuation amount in step ST707 was not less than the load fluctuation amount corresponding threshold value ΔP1 (the fluctuation amount ΔP is If the load fluctuation amount correspondence threshold ΔP1 is exceeded), it is assumed that the foreign matter Q (including the upper substrate 2 in the case of flowing two substrates as described later) is present on the substrate 2. In order to protect 1 and the substrate 2, the screen printing operation by the screen printer 1 is stopped, and the operator OP is notified by the image display via the display device 86 that the foreign matter Q exists on the substrate 2 (FIG. 12 screen printing operation stop process shown in step ST710).

  As a result, the squeegee 14 does not ride on 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.

  On the other hand, if the flag F is “1” in the flag determination step of step ST706 (that is, the printing pressure Pm is not within the appropriate load range Rg), the control device 80 uses the output from the linear scale 77. The foreign object Q is detected by determining whether or not the required fluctuation amount ΔT of the vertical position T of the squeegee 14 with respect to the squeegee base 60 is equal to or less than a threshold value (vertical position fluctuation amount corresponding threshold value ΔT1) (shown in FIG. 12). Foreign object detection step based on position fluctuation amount in step ST711). If the fluctuation amount ΔT of the vertical position T relative to the squeegee base 60 of the squeegee 14 determined by the output from the linear scale 77 is within the vertical position fluctuation amount corresponding threshold value ΔT1, the flag F is “0”. As in the case where there is, the process proceeds to the third determination step of step ST708, and the fluctuation amount ΔT of the vertical position T relative to the squeegee base 60 of the squeegee 14 obtained by the output from the linear scale 77 is equal to or less than the vertical position fluctuation amount corresponding threshold value ΔT1. (The fluctuation amount ΔT exceeds the vertical position fluctuation amount correspondence threshold ΔT1), the screen printing operation by the screen printer 1 is stopped on the assumption that the foreign matter Q exists on the substrate 2, The operator OP indicates that the foreign matter Q is present on the substrate 2 by displaying an image via the display device 86. Notification to (screen printing operation stopping process shown in step ST710 in FIG. 12).

  As described above, in the screen printing machine 1 according to the present embodiment, when the printing pressure Pm is within the appropriate load range Rg, the foreign matter can be accurately detected from the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 obtained through the load cell 76. However, when the printing pressure Pm is not within the appropriate load range Rg, the accuracy of detection of the axial load P of the squeegee lifting shaft 61 by the load cell 76 is reduced, so that the foreign matter having high accuracy can be obtained from the variation ΔP. Although the detection cannot be performed, the linear scale 77 directly measures the vertical position T of the squeegee 14 with respect to the squeegee base 60. Therefore, the detection accuracy of the variation ΔT is not reduced by the printing pressure Pm. As a result, accurate foreign object detection can be performed regardless of the range of the printing pressure Pm. Regardless of the size of the printing pressure for click 13, and is intended to test the foreign matter Q on the substrate 2 can be performed with high accuracy.

  Further, as shown in FIGS. 18A and 18B, the control device 80 is a region from one clamp member contact region R2 toward the substrate contact region R1 (that is, a region straddling the end of the substrate 2). When it is detected that the fluctuation amount ΔP of the axial load P of the squeegee lifting shaft 61 detected by the load cell 76 exceeds the load fluctuation amount correspondence threshold ΔP1, a plurality of substrates 2 are stacked (substrate 2). In step ST709, the screen printing operation is stopped, and the operator OP is notified by the image display via the display device 86 that the two-sheet-flowing state has occurred. 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 step ST7 (subroutine shown in FIG. 12) of the main routine is completed, the control device 80 raises the squeegee lifting shaft 61 with respect to the squeegee base 60 and separates the squeegee 14 from the mask 13 (step shown in FIG. 11). ST8 squeegee separation step).

  When the above-described squeegee separation step is completed, the control device 80 lowers the lifting table 22a with respect to the base table 21d (arrow E2 shown in FIG. 19A) and separates the substrate 2 from the mask 13 (FIG. 19). (A)). As a result, plate separation is performed, and the paste Pst is printed on the electrode 3 of the substrate 2 (plate separation step in step ST9 shown in FIG. 11).

  When the plate separating process of step ST9 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 moves the receiving unit 24c to ( The lower 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 section 23 (FIG. 19C). Thereby, the holding of the substrate 2 by the substrate holding unit 24 is released (the substrate holding releasing step of step ST10 shown in FIG. 11).

  When the substrate holding release process is completed, the control device 80 operates the horizontal moving unit 21 included 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 an interlocked manner, the substrate 2 on the conveyor unit 23 is transferred to the substrate carry-out conveyor 26, and the substrate 2 is carried out as it is to the outside of the screen printing machine 1 (substrate carry-out process of step ST11 shown in FIG. 11).

  After completing the substrate carry-out process, the control device 80 determines whether there is another substrate 2 to be screen-printed (fourth determination process in step ST12 shown in FIG. 11). As a result, if there is another substrate 2 to be screen-printed, the process returns to step ST1 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, the screen printing machine 1 according to the present embodiment includes the mask 13 that is in contact with the upper surface of the substrate 2, the squeegee base 60 that is provided above the mask 13 and moves in the horizontal plane, and the squeegee. A squeegee lifting shaft 61 that is lifted and lowered with respect to the base 60 and attached to the lower end of the squeegee lifting shaft 61. The squeegee base 60 is moved in the horizontal plane while in contact with the mask 13 from above. Squeegee 14 for transferring the paste Pst supplied onto the mask 13 to the substrate 2, a load cell 76 as a load detecting means for detecting the axial load P of the squeegee lifting shaft 61, and a squeegee for the squeegee 14. A linear scale 77 as position detecting means for detecting the vertical position T with respect to the base 60, and a squeegee 14 as a mask. 3, the variation ΔP of the axial load P of the squeegee lifting shaft 61 is obtained from the axial load P of the squeegee lifting shaft 61 detected by the load cell 76, or detected by the linear scale 77. A control device 80 is provided as a foreign matter detection means for detecting a foreign matter Q on the substrate 2 by obtaining a variation ΔT of the vertical position T of the squeegee 14 relative to the squeegee base 60 from the vertical position T relative to the squeegee base 60 of the squeegee 14. It has become.

  Further, the foreign matter detection method in the screen printer 1 according to the present embodiment includes a step of bringing the mask 13 into contact with the upper surface of the substrate 2 (substrate / mask contact step in step ST4) and a squeegee base provided above the mask 13. The step of abutting the squeegee 14 attached to the lower end of the squeegee lifting shaft 61 that is raised and lowered with respect to 60 from the upper side (the squeegee abutting step of step ST6), and the squeegee 14 abutting on the mask 13 The axial load P of the squeegee lifting shaft 61 is detected while the squeegee 14 is slid on the mask 13 to transfer the paste Pst on the mask 13 to the substrate 2 by moving the squeegee base 60 in the horizontal plane. Alternatively, by detecting the vertical position P of the squeegee 14 with respect to the squeegee base 60, the squeegee is moved up and down. The step of detecting the foreign matter Q on the substrate 2 by obtaining the fluctuation amount ΔP of the axial load P 61 or the fluctuation amount ΔT of the vertical position T of the squeegee 14 with respect to the squeegee base 60 (detection of foreign matter based on the load fluctuation amount of step ST707) Process or a foreign object detection process based on the amount of position fluctuation in step ST711).

  In the screen printer 1 and the foreign matter detection method in the screen printer 1 according to the present embodiment, in addition to the load cell 76 as load detecting means for detecting the axial load P of the squeegee lifting shaft 61, the squeegee 14 is applied to the squeegee base 60. A linear scale 77 is provided as position detecting means for detecting the vertical position T, and foreign matter detection based on the variation ΔP of the axial load P of the squeegee lifting shaft 61 detected by the load cell 76 is performed with high accuracy. If this is not possible, foreign matter detection can be performed by switching to foreign matter detection based on the fluctuation amount ΔT of the vertical position T of the squeegee 14 with respect to the squeegee base 60 detected by the linear scale 77. Regardless of the amount of printing pressure, the inspection of foreign matter Q on the substrate 2 is accurate. Can be done well.

In the screen printing machine 1 and the foreign matter detection method in the screen printing machine 1 according to the present embodiment, the foreign matter detection means (the control device 80) is a squeegee lifting shaft that is detected by the load cell 76 at the start of the sliding operation of the squeegee 14. When the axial load P of 61 is within the appropriate load range Rg, the foreign matter Q on the substrate 2 is detected based on the variation ΔP of the axial load P of the squeegee lifting shaft 61 and the squeegee 14 slides. When the axial load P of the squeegee lifting shaft 61 detected by the load cell 76 at the start of the squeegee is not within the appropriate load range Rg, the squeegee 14 on the substrate 2 based on the variation ΔT of the vertical position T relative to the squeegee base 60. since so as to perform the detection of the foreign matter Q (step ST702~ step ST708), a large switching the foreign substance detecting method of the printing pressure It is done smoothly according to the demands, so that work efficiency can be improved.

  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 elevating shaft 61 and the squeegee 14 is used as load detecting means for detecting the axial load of the squeegee elevating shaft 61. However, the structure of the load detecting means is not particularly limited. Similarly, in the above-described embodiment, the position detecting means for detecting the vertical position T of the squeegee 14 with respect to the squeegee base 60 is composed of a linear scale 77 provided between the squeegee 14 and the squeegee base 60. However, the configuration of the position detection means is not particularly limited.

  A screen printer capable of accurately inspecting foreign matter on a substrate regardless of the magnitude of printing pressure, and a foreign matter detection method in the screen printing machine are provided.

DESCRIPTION OF SYMBOLS 1 Screen printer 2 Board | substrate 13 Mask 14 Squeegee 60 Squeegee base 61 Squeegee raising / lowering shaft 75 Elastic body 76 Load cell (load detection means)
77 Linear scale (position detection means)
80 Control device (foreign matter detection means)
Pst paste Q Foreign matter

Claims (2)

A mask in contact with the upper surface of the substrate;
A squeegee base provided above the mask and moved in a horizontal plane;
A squeegee lifting shaft that is raised and lowered relative to the squeegee base;
A squeegee that is attached to the lower end of the squeegee lifting shaft and that slides on the mask by moving the squeegee base in the horizontal plane while in contact with the mask from above, and transfers the paste supplied on the mask to the substrate. When,
Load detecting means for detecting the axial load of the squeegee lifting shaft;
Position detecting means for detecting the vertical position of the squeegee with respect to the squeegee base;
When the squeegee is slid on the mask, the fluctuation amount of the axial load of the squeegee lifting shaft is obtained from the axial load of the squeegee lifting shaft detected by the load detecting means, or the squeegee detected by the position detecting means is detected. A foreign matter detecting means for detecting a foreign matter on the substrate by obtaining a fluctuation amount of the vertical position of the squeegee with respect to the squeegee base from a vertical position with respect to the squeegee base;
The foreign matter detecting means is based on the amount of variation in the axial load of the squeegee lifting shaft when the axial load of the squeegee lifting shaft detected by the load detecting means at the start of the sliding operation of the squeegee is within an appropriate load range. If the axial load of the squeegee lifting shaft detected by the load detecting means at the start of the sliding operation of the squeegee is not within the appropriate load range, the foreign matter on the board is detected , and the squeegee's vertical direction with respect to the squeegee base screen printing machine, characterized in that the detection of foreign matter on the substrate based on the amount of change of position. Contacting the mask with the top surface of the substrate;
Contacting the squeegee attached to the lower end of the squeegee lifting shaft that is lifted and lowered with respect to the squeegee base provided above the mask from above;
While the squeegee is in contact with the mask, the squeegee base is moved in the horizontal plane so that the squeegee slides on the mask and the paste on the mask is transferred to the substrate while detecting the axial load of the squeegee lifting shaft. Alternatively, by detecting the vertical position of the squeegee relative to the squeegee base, the amount of variation in the axial load of the squeegee lifting shaft or the amount of variation in the vertical position of the squeegee relative to the squeegee base is obtained to detect foreign matter on the substrate. Process ,
Determining whether the axial load of the squeegee lifting shaft detected by the load detecting means at the start of the sliding operation of the squeegee is within an appropriate load range ,
When an axial load of the detected squeegee elevating shaft were within the appropriate load range, performs detection of foreign matter on the substrate based on the variation amount of the axial load of the squeegee elevating shaft, detected squeegee elevating shaft when the axial load was not within the proper load range, the foreign matter detection method in a screen printing machine, characterized in that the detection of foreign matter on the substrate based on the variation amount of the vertical position relative to the squeegee base squeegees.

Images