JP5768213B2 - Screen printing machine and screen printing method - Google Patents

Description

  The present invention relates to a screen printing machine and a screen printing method for printing a paste on a substrate through a mask.

  Conventionally, a screen printer is known as an apparatus for printing a paste such as solder on an electrode of a substrate. The screen printing machine slides on a mask for screen printing, a substrate holding unit that holds the substrate below the mask, and a mask that is in contact with the substrate held by the substrate holding unit, and is supplied onto the mask. And a squeegee for transferring the paste to the substrate. A mask provided in such a screen printing machine includes a metal plate portion having an opening and a sheet-like portion made of resin (for example, polyester) provided around the metal plate portion, and an outer periphery of the sheet-like portion. The part is fixed to the lower surface of the rectangular mask frame with an adhesive. The mask is placed at a predetermined position by placing the mask frame on a mask holder made of a pair of rail-like members provided above the substrate holding portion.

  As described above, in the screen printing machine, the squeegee slides on the mask in contact with the substrate. When the squeegee slides, the positional displacement between the substrate and the mask (that is, between the substrate electrode and the mask opening). In order to prevent the occurrence of misalignment), the substrate and the mask are fixed to each other by adsorbing the mask by the adsorbing means provided on the side of the substrate holding portion. (For example, Patent Document 1).

Japanese Patent Laid-Open No. 5-92544

  However, in the above conventional screen printing machine in which the mask and the mask are fixed to each other by adsorbing the mask by the adsorbing means, a part of the adhesive for adhering the sheet-like portion of the mask to the mask frame is the lower surface of the mask When the adhesive layer (adhesive layer) is formed around the side, the mask is lifted from the mask holder by the thickness of the adhesive layer. When the thickness of the adhesive layer is relatively large due to variations or the like, even if an attempt is made to suck the mask by the suction means, it cannot be sucked well, and the mutual fixing state between the substrate and the mask is not good. There is a problem in that there are cases where the printing state becomes insufficient and the printing state becomes poor.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a screen printing machine and a screen printing method capable of sufficiently securing a mutual fixing state between a substrate and a mask and preventing a printing state from becoming defective.

The screen printer according to claim 1 raises a mask for screen printing, a substrate holding unit that holds the substrate below the mask, and a suction unit that can be moved up and down, and the suction unit at a position above the substrate. After attracting the mask, the attracting unit is lowered to draw the mask downward and contact the substrate, the storage unit storing the distance data for raising the attracting unit , and the mask attracting unit to contact the substrate A squeegee that slides on the mask and transfers the paste supplied on the mask to the substrate, and raises the suction unit based on distance data stored in the storage unit. The mask is sucked by the suction portion at the position .

According to a second aspect of the present invention, there is provided a screen printing method comprising: a step of holding a substrate below a screen printing mask; and a lift unit that can be moved up and down is raised based on distance data stored in the storage unit . After the mask is sucked by the suction part at the position, the suction part is lowered to draw the mask downward and contact the substrate, and the squeegee is slid on the mask in contact with the substrate and supplied onto the mask. Transferring the paste to the substrate.

  In the present invention, the suction part that can be raised and lowered is raised, the mask is sucked by the suction part at a position above the substrate, and then the suction part is lowered to draw the mask downward and contact the substrate. And the thickness of the adhesive layer formed by the adhesive that bonds the mask to the mask frame wraps around the lower surface of the mask frame is relatively large due to quality variations in the mask manufacturing process, etc. In addition, since the mask can be surely adsorbed and the mask can be drawn toward the substrate side, it is possible to sufficiently secure the mutual fixing state between the substrate and the mask and to prevent the printing state from becoming defective.

The perspective view of the principal part of the screen printer in one embodiment of this invention The side view of the principal part of the screen printer in one embodiment of this invention The mask holder with which the screen printing machine in one embodiment of the present invention is provided, and (a) top view (b) partial sectional view of the mask held by the mask holder The flowchart of the main routine which shows the execution procedure of the screen printing operation by the screen printer in one embodiment of this invention (A) (b) Explanatory drawing of the execution procedure of the screen printing work by the screen printer in one embodiment of this invention (A) (b) Explanatory drawing of the execution procedure of the screen printing work by the screen printer in one embodiment of this invention (A) (b) Explanatory drawing of the execution procedure of the screen printing work by the screen printer in one embodiment of this invention (A) (b) Explanatory drawing of the execution procedure of the screen printing work by the screen printer in one embodiment of this invention

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, the screen printing machine 1 executes a screen printing operation in which a paste Pt such as solder is screen printed on each of a large number of electrodes 3 provided on a substrate 2. A pair of mask holders 12 provided above the base 11, a screen printing mask 13 held in a horizontal posture by the mask holder 12, a substrate holding unit moving mechanism 14 provided on the base 11, and a mask 13 Below, the substrate holding unit 15 moved by the substrate holding unit moving mechanism 14, the mask drawing portion 16 provided in the substrate holding unit 15, the squeegee head 17 provided above the mask 13, the substrate holding unit 15 and the mask 13 Between the camera unit 18 and the display device 19 provided in the area between the And a control unit 20 for performing.

  1 and 3A, the mask holder 12 is composed of a pair of rail-like members provided extending horizontally and parallel above the base 11, and the mask 13 is attached to each electrode 3 on the substrate 2. A metal plate portion 13a made of a rectangular thin metal plate having a number of corresponding openings 13h, and a resin (for example, polyester) that supports the four sides of the metal plate portion 13a and extends outward from the metal plate portion 13a. It consists of a sheet-like portion 13b. The outer periphery (four sides) of the sheet-like portion 13b is supported by a rectangular mask frame 13W in plan view, and two opposite sides of the four sides of the mask frame 13W are supported by the mask holder 12. Here, as shown in FIG. 3B, which is a partial cross-sectional view taken along the line VV in FIG. 3A, the sheet-like portion 13 b of the mask 13 is attached to the lower surface of the mask frame 13 </ b> W with an adhesive BD. Is glued by.

  In FIG. 1, two substrate-side marks 2 m are provided at one diagonal position on the substrate 2, and two masks corresponding to these two substrate-side marks 2 m are provided on the metal plate portion 13 a of the mask 13. A side mark 13m is provided (see also FIG. 3A). When the substrate 2 is brought into contact with the mask 13 with the two substrate-side marks 2m and the two mask-side marks 13m aligned vertically, the electrode 3 of the substrate 2 and the opening 13h of the mask 13 are aligned. .

  The substrate holding unit moving mechanism 14 is composed of an XYZ robot, and the substrate holding unit 15 is moved (rotated in the horizontal plane (XY plane)) by the substrate holding unit moving mechanism 14 as shown in FIGS. Unit base 21 that is moved in the vertical direction (Z-axis direction), a pair of conveyors 22 that are attached to the unit base 21 and transport the substrate 2 in one direction (X-axis direction) in the horizontal plane, and the unit base Opening / closing in a horizontal plane direction (Y-axis direction) perpendicular to the conveyance direction (X-axis direction) of the substrate 2 and the lower receiving part 24 raised and lowered by the lower-receiving part lifting cylinder 23 and the substrate 2 It consists of a pair of clamp members 25 provided freely.

  The pair of conveyors 22 carries the substrate 2 in one direction (X-axis direction) in the horizontal plane and positions it at a predetermined work position (position shown in FIG. 1). The lower receiving portion 24 is supported by lifting the substrate 2 from below so that both ends of the substrate 2 positioned at the work position by being moved up and down by the lower receiving portion raising / lowering cylinder 23 are separated from the conveyor 22 upward. Both sides of the substrate 2 lifted and supported by the lower receiving portion 24 are sandwiched (clamped) from the Y-axis direction and held.

  In FIG. 1 and FIG. 2, the mask pulling portion 16 includes two suction pad lifting cylinders 31 provided on the outer side in the Y-axis direction of the clamp member 25, and two suction portions lifted and lowered by each suction pad lifting cylinder 31. It consists of a suction pad 32. Each suction pad 32 is provided with a vacuum pipe 32a opened on the upper surface of the suction pad 32, and this vacuum pipe 32a is connected to a suction mechanism 32M for supplying a vacuum pressure into the vacuum pipe. For this reason, when a vacuum pressure is supplied from the suction mechanism 32M into the vacuum line with the mask 13 (metal plate portion 13a) in contact with the upper surface of the suction pad 32, the mask is sucked to the suction pad 32.

  The mask drawing portion 16 is located above the pair of clamp members 25 that hold the substrate 2 by raising the two suction pads 32 by the two suction pad lifting cylinders 31 in a state where the substrate 2 is positioned below the mask 13. After the mask 13 is sucked by the suction pad 32 at the position, the suction pad 32 is lowered to draw the mask 13 downward and bring the mask 13 into contact with the substrate 2.

  1 and 2, the squeegee head 17 moves up and down below the moving base 41 by operating the plate-shaped moving base 41, the two squeegee lifting cylinders 42 attached to the moving base 41, and the two squeegee lifting cylinders 42. Two squeegee units 43 are provided. The squeegee head 17 (moving base 41) is reciprocated in the horizontal direction (Y-axis direction) with respect to the mask 13 by a squeegee head moving mechanism 44 including an actuator (not shown).

  1 and 2, each squeegee unit 43 includes a squeegee holder 43a attached to the piston rod 42a of the squeegee lifting cylinder 42 and extending in the X-axis direction, and a squeegee 43b made of a thin plate member attached to the squeegee holder 43a. In each squeegee unit 43, the piston rod 42a of the squeegee elevating cylinder 42 moves up and down below the moving base 41 by a downward projecting operation, but the vertical position of the mask 13 and the moving base 41 does not change. By lowering the unit 43 relative to the moving base 41, the squeegee 43b can be brought into contact with the mask 13 from above.

  An operator (not shown) who operates the screen printing machine 1 is usually located on one side of the two squeegees 43b facing each other (Y-axis direction). The front side of the screen printer 1 and the opposite side are the rear side of the screen printer 1.

  1 and 2, the camera unit 18 includes a lower imaging camera 18a whose imaging field is directed downward and an upper imaging camera 18b whose imaging field is directed upward. The camera unit 18 is moved in the horizontal plane in a region between the substrate holding unit 15 and the mask 13 by a camera moving mechanism 18M (FIG. 2) including an actuator (not shown).

  The substrate holding unit 15 conveys the substrate 2 by the conveyor 22 and positions the substrate 2 at the working position, the receiving operation by the lower receiving portion 24 for the substrate 2 located at the working position, and the clamping operation by the pair of clamping members 25 are performed by the control device 20. Is performed by controlling the operation of the substrate holding mechanism 15M (FIG. 2) including the actuator including the above-described under-lifting cylinder 23, and moving the substrate holding unit 15 holding the substrate 2 in the horizontal plane direction and in the vertical direction. The operation is performed when the control device 20 controls the operation of the substrate holding unit moving mechanism 14 described above.

  The lifting / lowering operation of the two suction pads 32 of the mask pulling unit 16 is simultaneously lifted / lowered by the synchronous operation of the two suction pad lifting / lowering cylinders 31, and the controller 20 performs the suction operation of the mask 13 by the two suction pads 32. This is done by controlling the operation of the mechanism 32M.

  The reciprocating movement of the squeegee head 17 (moving base 41) in the Y-axis direction is performed when the control device 20 controls the operation of the squeegee head moving mechanism 44 described above, and each squeegee unit 43 (and hence the squeegee 43b) moves. The raising / lowering operation with respect to the base 41 is performed when the control device 20 controls the operation of the two squeegee raising / lowering cylinders 42.

  The movement operation of the camera unit 18 in the horizontal plane is performed by the control device 20 performing operation control of the above-described camera movement mechanism 18M. The control of the imaging operation by the lower imaging camera 18a and the imaging operation by the upper imaging camera 18b are respectively performed by the control device 20, and obtained by the image data obtained by the imaging operation of the lower imaging camera 18a and the imaging operation of the upper imaging camera 18b. The received image data is transmitted to the control device 20 and subjected to image recognition processing in the image recognition unit 20a (FIG. 2) of the control device 20.

  Next, the execution procedure of the screen printing operation (screen printing method) by the screen printer 1 will be described with reference to the flowchart of FIG. 4 and the explanatory diagrams of FIGS. When the control device 20 of the screen printing machine 1 detects that the substrate 2 has been sent from another device or the like (not shown) installed on the upstream side of the screen printing machine 1, the conveyor 22 of the substrate holding unit 15. Is operated to carry the substrate 2 into the screen printer 1 (step ST1 shown in FIG. 4), and the substrate holding mechanism 15M is controlled to hold the substrate 2 (FIG. 5A). Step ST2 shown).

  Here, specifically, the holding of the substrate 2 is performed by pushing up the lower receiving portion 24 by the lower receiving portion lifting cylinder 23 to lift the substrate 2 from the conveyor 22 (an arrow shown in FIG. 5A). A) It is performed by driving the pair of clamp members 25 in the closing direction and sandwiching both ends of the substrate 2 (arrow B shown in FIG. 5A).

  As described above, in the present embodiment, the substrate holding unit 15 is a substrate holding unit that holds the substrate 2 below the mask 13, and the above-described step ST <b> 2 is a step of holding the substrate 2 below the mask 13. It has become.

  When holding the substrate 2, the control device 20 controls the operation of the camera moving mechanism 18 </ b> M, positions the lower imaging camera 18 a immediately above the substrate-side mark 2 m provided on the substrate 2, and then attaches the substrate to the lower imaging camera 18 a. The side mark 2m is imaged and the position of the substrate 2 is grasped from the image data. The upper imaging camera 18b is positioned immediately below the mask side mark 13m provided on the mask 13 and then the upper imaging camera 18b. The mask side mark 13m is imaged and the position of the mask 13 is grasped from the image data. Then, the substrate holding unit 15 is moved in the horizontal plane direction, and the substrate 2 is aligned with the mask 13 in the horizontal plane direction so that the substrate side mark 2m and the mask side mark 13m face each other vertically (FIG. 4). Step ST3).

  When the alignment of the substrate 2 with respect to the mask 13 is finished, the control device 20 controls the operation of the substrate holding unit moving mechanism 14 to raise the substrate holding unit 15 with respect to the base 11 (in FIG. 5B). The arrow C1 shown) and the upper surface of the substrate 2 (and the upper surfaces of the pair of clamp members 25) are brought closer to the lower surface of the metal plate portion 13a of the mask 13 from below. As a result, the upper surface of the substrate 2 and the lower surface of the mask 13 (the lower surface of the metal plate portion 13a) are brought into close proximity (FIG. 5B, step ST4 shown in FIG. 4).

  When the upper surface of the substrate 2 is brought close to the lower surface of the mask 13 from below in step ST4, the control device 20 controls the operation of the suction pad lifting cylinder 31 to raise the pair of suction pads 32 (see FIG. 6A). Arrow D1), the upper surface of each suction pad 32 is brought into contact with the lower surface of the metal plate portion 13a of the mask 13 at a position above the pair of clamp members 25 holding the substrate 2, and the operation of the suction mechanism 32M. Control is performed to supply a vacuum pressure into the vacuum line in each suction pad 32, and the pair of suction pads 32 cause the metal plate portion 13a of the mask 13 to be sucked (FIG. 6 (a), step ST5 shown in FIG. 4). . At this time, distance data for raising the suction pad 32 for suction of the mask 13 is stored in advance in a storage unit 20b (FIG. 2) provided in the control device 20.

  When the control device 20 adsorbs the mask 13 to the pair of suction pads 32 as described above, the control device 20 controls the operation of the suction pad lifting cylinder 31 to lower the pair of suction pads 32 (see FIG. 6B). The arrow D2) and the metal plate portion 13a of the mask 13 are drawn downward to bring the mask 13 into contact with the substrate 2 (FIG. 6B, step ST6 shown in FIG. 4). As a result, the electrode 3 on the substrate 2 and the opening 13h of the mask 13 match, and the substrate 2 and the mask 13 are fixed to each other.

  As described above, in the present embodiment, the pair of mask drawing portions 16 raises the suction pad 32 that can be moved up and down, and sucks the mask 13 with the suction pad 32 at a position above the substrate 2, and then sucks the suction pad 32. By being lowered, it serves as a mask drawing means for drawing the mask 13 downward and bringing it into contact with the substrate 2. In step ST5 and step ST6, the suction pad 32 that can be moved up and down is raised, the mask 13 is sucked by the suction pad 32 at a position above the substrate 2, and then the suction pad 32 is lowered to lower the mask 13. This is a process of drawing the substrate downward and bringing it into contact with the substrate 2.

  When the control device 20 brings the substrate 2 into contact with the mask 13, the control device 20 displays a message for prompting the operator to supply the paste Pt on the display device 19 (step ST7 shown in FIG. 4). On the other hand, the operator visually checks the paste Pt remaining on the mask 13 and determines whether or not to supply (supplement) the paste Pt based on the amount of the paste Pt. When it is determined that the paste Pt should be supplied, the paste Pt is supplied onto the mask 13 by using a separately prepared paste supply syringe 50 (FIG. 7A). When the supply of the paste Pt is finished, the operation restart button 60 (FIG. 2) connected to the control device 20 is operated. The operator operates the operation restart button 60 even when it is determined that the supply of the paste Pt is unnecessary.

  In step ST7, the control device 20 displays a message prompting the supply of the paste Pt on the display device 19, and then determines whether or not the operation resumption button 60 has been operated at regular intervals (step shown in FIG. 4). ST8) When it is detected based on the signal output from the operation resuming button 60 that the operator has operated the operation resuming button 60, the squeegee head 17 is positioned above one of the pair of clamp members 25. Then, one of the two squeegees 43b is lowered (arrow E1 shown in FIG. 7B), and the lower end of the squeegee 43b is brought into contact with the upper surface of the mask 13 in contact with the clamp member 25 ( Step ST9 shown in FIG.

  At this time, the squeegee 43b that is lowered (abuts against the mask 13) is the front squeegee 43b when the squeegee head 17 is positioned above the front clamp member 25, and the squeegee head 17 is moved to the rear clamp member. When it is positioned above 25, it is the rear squeegee 43b.

  When the squeegee 43 b is brought into contact with the upper surface of the mask 13 that is in contact with the clamp member 25 by the operation of the squeegee lifting cylinder 42, the control device 20 makes the squeegee head 17 in a state where the squeegee 43 b is brought into contact with the upper surface of the mask 13. (That is, the squeegee 43b) is moved in the horizontal direction (Y-axis direction) with respect to the mask 13 (arrow F shown in FIG. 7B), and the squeegee 43b is slid on the mask 13 to thereby move the mask 13 The paste Pt supplied above is pushed into the opening 13h of the mask 13 to transfer the paste Pt to the electrode 3 (step ST10 shown in FIG. 4).

  As described above, the squeegee 43 b slides on the mask 13 that is in contact with the substrate 2 by the mask drawing portion 16 and transfers the paste Pt supplied onto the mask 13 to the substrate 2. Step ST10 is a step of sliding the squeegee 43b on the mask 13 in contact with the substrate 2 to transfer the paste Pt supplied on the mask 13 to the substrate 2.

  In step ST10, the control device 20 moves the squeegee 43b from the region on the mask 13 in contact with the one clamp member 25 to the other clamp member 25 through the region on the mask 13 in contact with the substrate 2. To the area on the mask 13 that is in contact with. FIG. 7B shows an example in which the front squeegee 43 b is moved from the region on the mask 13 in contact with the front clamp member 25 to the region on the mask 13 in contact with the rear clamp member 25. However, when the rear squeegee 43b is moved from the region on the mask 13 in contact with the rear clamp member 25 to the region on the mask 13 in contact with the front clamp member 25, the squeegee head 17 is not shown in FIG. It is moved in the direction opposite to the arrow F shown in 7 (b).

  When the control device 20 detects that the squeegee 43b reaches the region on the mask 13 in contact with the other clamp member 25 from the region on the mask 13 in contact with the one clamp member 25, the transfer of the paste Pt is completed. After the movement of the squeegee head 17 is stopped, the squeegee 43b that is in contact with the mask 13 is raised with respect to the moving base 41 (arrow E2 shown in FIG. 8A), and the squeegee 43b is moved to the mask 13 (Step ST11 shown in FIG. 4).

  After the squeegee 43b is separated from the mask 13, the control device 20 operates the suction pad lifting cylinder 31 to raise the pair of suction pads 32 to the position where the mask 13 is sucked in step ST5 (FIG. 8A). The arrow D3 shown in the figure and the suction of the mask 13 by the pair of suction pads 32 are released, whereby the substrate 2 is separated from the mask 13 (FIG. 8A) (step ST12 shown in FIG. 4).

  The control device 20 operates the substrate holding unit moving mechanism 14 while operating the suction pad raising / lowering cylinder 31 to lower the pair of suction pads 32 (arrow D4 shown in FIG. 8B) when the plate separation is completed. The substrate holding unit 15 is lowered (arrow C2 shown in FIG. 8B), and the control device 20 operates the substrate holding mechanism 15M to open the pair of clamp members 25 and then lowers the receiving portion 24. Is lowered to lower both ends of the substrate 2 onto the pair of conveyors 22. Thereby, the holding of the substrate 2 by the substrate holding unit 15 is released (see FIG. 2, step ST13 shown in FIG. 4).

  After releasing the holding of the substrate 2, the control device 20 operates the substrate holding unit moving mechanism 14 to move the substrate holding unit 15 in the horizontal plane, aligns the direction of the conveyor 22, and then operates the conveyor 22. The board | substrate 2 is carried out to the exterior of the screen printer 1 (step ST14 shown in FIG. 4).

  If the board | substrate 2 is carried out, the control apparatus 20 will judge whether there exists another board | substrate 2 which performs screen printing (step ST15 shown in FIG. 4). 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, in the screen printer 1 and the screen printing method in the present embodiment, the suction pad 32 (suction part) that can be raised and lowered is raised, and the mask 13 is placed by the suction pad 32 at a position above the substrate 2. After the suction, the suction pad 32 is lowered to draw the mask 13 downward to bring the mask 13 into contact with the substrate 2. As shown in FIG. 3B, the mask 13 (sheet-like portion 13b) ) Is bonded to the mask frame 13W and the thickness T of the adhesive layer formed by wrapping around the lower surface of the mask frame 13W is relatively large due to quality variations in the manufacturing process of the mask 13 or the like. Even so, the mask 13 can be reliably adsorbed and the mask 13 can be pulled toward the substrate 2 side, so that the mutual fixing state between the substrate 2 and the mask 13 is sufficient. It is possible to prevent the securing to the printing state becomes poor.

  Provided are a screen printing machine and a screen printing method capable of sufficiently securing a mutual fixing state between a substrate and a mask and preventing a printing state from becoming defective.

1 Screen Printing Machine 2 Substrate 13 Mask 15 Substrate Holding Unit (Substrate Holding Unit)
16 Mask drawing part (mask drawing means)
32 Suction pad (Suction part)
43b Squeegee Pt Paste

Claims (2)

A mask for screen printing,
A substrate holder for holding the substrate under the mask;
A mask pulling means that lifts and lowers the suckable portion, sucks the mask by the sucking portion at a position above the substrate, and then lowers the sucking portion to draw the mask downward and contact the substrate;
A storage unit for storing distance data for raising the suction unit;
A squeegee that slides on the mask in contact with the substrate by the mask drawing means and transfers the paste supplied on the mask to the substrate ;
A screen printing machine , wherein the suction unit is lifted based on distance data stored in the storage unit, and the mask is sucked by the suction unit at a position above the substrate . Holding the substrate below the mask for screen printing;
The suction unit that can be moved up and down is lifted based on the distance data stored in the storage unit , and after the mask is sucked by the suction unit at a position above the substrate, the suction unit is lowered to draw the mask downward to the substrate. A step of contacting;
And a step of sliding a squeegee on the mask in contact with the substrate and transferring the paste supplied on the mask to the substrate.

Images