JP2005305884A - Screen printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that it is difficult to securely hold a substrate with warpage on a table surface in a conventional printing machine and besides, a correct printing work cannot be performed due to the positional deviation of the substrate. <P>SOLUTION: This screen printing machine is equipped with a sliding mechanism in the Y axial direction on an X axial camera transfer frame for moving/positioning a substrate mark recognition camera. In addition, the printing machine has a substrate warpage correction means with a vertically movable substrate keep plate is arranged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a screen printing machine used for supplying an electronic material paste such as cream solder to an electronic circuit board, and in particular, when printing on a thin board having warpage, the board warpage is corrected and the board is reliably adsorbed. The present invention relates to a screen printing machine suitable for obtaining a good printing performance by bringing a substrate into close contact with a jig.

  As a conventional screen printing machine, as described in Patent Document 1, a printing table having an X-axis, Y-axis, and θ-axis positioning mechanism and a lifting mechanism, a mask having a transfer pattern as an opening, a substrate and a mask are provided. A camera for imaging the positioning mark, a squeegee, a squeegee lifting mechanism and a squeegee head provided with a horizontal movement mechanism, a control device for controlling these mechanisms, and a substrate carried into the device and placed on a printing table The position and the position of the mask are positioned based on the image captured by the camera, and then the table is raised to bring the substrate close to the mask, and the mask is brought into contact with the substrate by a squeegee and the mask opening is made of cream solder or the like Fill the paste, lower the table, and transfer the paste onto the substrate by separating the substrate from the mask. After, it is to carry the substrate from the apparatus.

Japanese Patent Laid-Open No. 9-11440

  Since an electronic circuit board to which an electronic material paste such as cream solder is supplied by a screen printing machine is generally composed of a composite material, it may be warped rather than a uniform flat plate. On the other hand, in the case of a thin substrate such as a flexible substrate, a general clamping method for pressing the side surface of the substrate cannot be used. For this reason, a method is used in which a substrate suction jig is disposed on the printing table and the substrate is restrained on the printing table by sucking the substrate onto the suction jig. However, in this case, if the substrate is warped, there is a gap between the upper surface of the suction jig and the lower surface of the substrate, and the suction jig may not be able to reliably suck and fix the substrate. At this time, since the substrate is displaced during printing, printing failure often occurs.

  The present invention simply and effectively corrects the warp of the substrate, and means for obtaining good printing performance by securely bringing the substrate into close contact with the substrate suction jig even for a thin substrate with irregular warpage. The purpose is to provide.

  In order to achieve the above object, the screen printing machine of the present invention is characterized in that a substrate warp correction means capable of moving up and down is disposed on a camera X axis moving frame for moving and positioning a substrate mark recognition camera. . Furthermore, by making the mounting position of the substrate warp correction means movable in the Y direction on the camera X-axis moving frame, the substrate warpage correction means can always hold near the center of the substrate according to the size of the substrate to be printed. It is possible to do it.

  By using the screen printing machine of the present invention, it is possible to effectively correct the warpage of the substrate and to ensure that the substrate is firmly attached to the substrate suction jig even for a thin substrate with warpage, thereby obtaining good printing performance. Is possible.

  An embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a schematic diagram showing the configuration of the screen printing machine of the present invention.

  In FIG. 1, a squeegee head 3 is provided at the upper part of a main body frame 1 of the screen printing machine, guided by a pair of guide rails 2 and movable in the front-rear direction in the figure. The squeegee head 3 is driven by rotating the ball screw 4 by a motor (not shown).

  A squeegee 5 is mounted on the squeegee head 3. The squeegee 5 can be moved up and down by a squeegee lifting cylinder 6. A plate frame receiver 7 is provided on the main body frame 1, and a plate frame 9 with a screen (mask) 8 having a printing pattern as an opening is set on the plate frame receiver 7. The printing table 10 includes an XYθ table 11 having a drive mechanism for moving in each direction of XYθ and a table lifting mechanism (not shown). A substrate receiving conveyor 12 is separately provided on the upper surface side of the printing table 10, and the substrate 15 carried by the substrate carrying conveyor 13 is received on the printing table 10, and when printing is completed, the substrate 15 is discharged to the substrate carrying conveyor 14. To do. The fully automatic screen printer has a function of automatically aligning the mask 8 and the substrate 15. The CCD camera 16 takes an image of alignment marks provided on the mask 8 and the substrate 15 and recognizes the position. As will be described later, a substrate suction jig for fixing the substrate 15 on the table is provided on the upper surface of the printing table 10.

  Next, the operation of the screen printing machine of the present invention will be described with reference to FIG.

  The substrate 15 on which the electronic material paste is printed is supplied to the substrate receiving conveyor 12 by the substrate transport conveyor 13 and fixed at a predetermined position on the printing table 10. Subsequently, the CCD camera 16 takes an image of a position recognition mark (not shown) provided on the substrate 15 and the mask 8 and transfers it to a control device (not shown). An image processing unit (not shown) in the control device obtains the amount of positional deviation between the mask 8 and the substrate 15 from the image data. Based on the result, the control device operates the drive unit of the XYθ table 11 of the printing table 10 to move the XYθ table 11 so as to eliminate the deviation, thereby correcting the position of the substrate 15 with respect to the mask 8. Thereafter, the printing table 10 is raised and the substrate 15 and the mask 8 are brought into contact with each other. Then, the squeegee 5 is lowered by the squeegee lifting cylinder 6, and the electronic material paste supplied on the mask 8 by the movement of the squeegee head 3 is filled in the opening provided in the mask 8. When the squeegee 5 is lifted after a certain distance stroke, the printing table 10 is lowered, the mask 8 and the substrate 15 are separated, and the electronic material paste filled in the opening of the mask 8 is transferred to the substrate 15.

  Then, the substrate 15 printed with the electronic material paste is sent to the next process via the substrate carry-out conveyor 14.

  In the present invention, a device is devised so that proper printing can be performed even when a substrate 15 having a warp is supplied in the above printing process. For this purpose, the substrate warp correction means 17 is used.

  Hereinafter, the device will be described. FIG. 2 is an AA arrow view of FIG.

  In FIG. 2, elements denoted by the same reference numerals as those in FIG. 1 indicate the same elements as in FIG.

  In FIG. 2, reference numeral 18 denotes a substrate suction jig disposed on the printing table 10. A vacuum suction hole (not shown) is opened on the upper surface of the substrate suction jig 18, and the substrate 15 (not shown) carried on the upper surface of the substrate suction jig 18 has a function of sucking and fixing by vacuum. ing.

  The camera X axis moving frame 19 is for moving the CCD camera 16 for substrate mark recognition and positioning it at the imaging position. The camera X-axis moving frame 19 is positioned in the X-axis direction by a camera X-axis positioning mechanism including a camera X-axis drive motor 20, a ball screw 21 and a linear guide 22. A camera Y-axis drive motor 23 is disposed on the camera X-axis moving frame 19, and the camera 16 is positioned in the Y-axis direction by a camera Y-axis positioning mechanism including a camera Y-axis drive motor 23 and a ball screw 24. .

  The substrate warp correction means 17 is attached to the camera X axis moving frame 19. Here, the substrate warp correction means 17 moves the camera X axis via a slide mechanism (not shown) so that the position of the camera X axis movement frame 19 can be easily adjusted with respect to the Y axis direction. Coupled to the frame 19. In FIG. 2, reference numeral 25 denotes a mask cleaning device, and 26 denotes a control device, but the description thereof is omitted because it is not important for the present invention.

  FIG. 3 is a view taken along the line B-B of FIG. 2 and is a diagram for explaining an example of the structure of the substrate warp correction means 17.

  In FIG. 3, parts denoted by the same symbols as those in FIGS. 1 and 2 are the same parts as in FIGS. The substrate pressing plate 171 is attached to the upper and lower cylinders 172 by the substrate pressing plate mounting bracket 174 via the relay plate 173. The upper and lower cylinders 172 are attached to the camera X axis moving frame 19 via a bracket 175. The substrate pressing plate 171 is preferably formed of a conductive plastic plate, for example, so as not to damage the substrate and to be able to remove static electricity. In addition, by adopting a configuration in which the substrate pressing plate 171 and the relay plate 173 are fixed via the mounting bracket 174, even when the size of the substrate 15 changes, it can be easily replaced with a substrate pressing plate suitable for the substrate size. .

  Hereinafter, the operation of the screen printing machine provided with the substrate warpage correction apparatus of the present invention will be described with reference to FIGS.

  FIG. 4 is a view showing a state in which the substrate 15 is carried on the substrate suction jig 18 disposed on the printing table 10. Here, the loaded substrate 15 is irregularly warped, and the substrate 15 cannot be sucked and fixed onto the substrate sucking jig 18 even if the sucking operation is performed in this state. Therefore, the camera X-axis moving frame and the Y-axis direction slide mechanism are operated to move the substrate pressing plate 171 of the substrate warp correcting means 17 directly above the substrate 15 as shown in FIG.

  Thereafter, the substrate warp correction device 17 is moved onto the printing table 10. Then, as shown in FIG. 6, the upper and lower cylinders 172 of the substrate warp correction device 17 are extended to press the entire surface of the substrate 15 with the substrate pressing plate 171 to correct the warp. Thereby, the lower surface of the substrate 15 is securely adhered to the upper surface of the substrate suction jig 18. By performing the suction operation while being in close contact with the upper surface of the substrate suction jig 18, the substrate 15 is suction fixed to the substrate suction jig 18. When the substrate 15 is sucked and fixed to the substrate sucking jig 18, the upper and lower cylinders 172 are contracted as shown in FIG. 7 to separate the substrate pressing plate 171 from the surface of the substrate 15. In this state, the camera X-axis moving frame 19 is moved, and the CCD camera 16 images the fiducial mark disposed on the substrate 15. FIG. 8 is a diagram showing a state in which the board mark recognition camera 16 moves on the fiducial mark disposed on the board 15 and images the mark.

  When these series of operations are completed, the camera 16 and the substrate warp correction device 17 return to their standby positions as shown in FIG. 9, and thereafter, a series of printing operations are repeatedly executed.

  In the above description, the case where the substrate cannot be sucked and held by the substrate sucking jig 18 has been described as an example. However, when the substrate can be sucked and held although the substrate warpage is small and incomplete, the substrate correction mechanism is not operated. In some cases, the substrate and the mask cannot be reliably aligned. That is, the alignment mark on the substrate side is deviated from the design value due to warpage or deflection of the substrate.

  Therefore, as described above, by operating the substrate warp correction mechanism, the substrate can be held in close contact with the table even if the substrate is warped or bent, so that the positional deviation between the substrate and the mask can be reliably corrected. Highly accurate printing can be realized.

It is the schematic for demonstrating a structure and operation | movement of the screen printer of this invention. FIG. 2 is an AA arrow view of FIG. FIG. 3 is a view taken along arrow BB in FIG. It is a BB arrow line view for demonstrating operation | movement of the screen printer of this invention. It is a BB arrow line view for demonstrating operation | movement of the screen printer of this invention. It is a BB arrow line view for demonstrating operation | movement of the screen printer of this invention. It is a BB arrow line view for demonstrating operation | movement of the screen printer of this invention. It is a BB arrow line view for demonstrating operation | movement of the screen printer of this invention. It is a BB arrow line view for demonstrating operation | movement of the screen printer of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer body frame, 3 ... Squeegee head, 5 ... Squeegee, 6 ... Squeegee lifting cylinder, 8 ... Mask, 9 ... Plate frame, 10 ... Printing table, 15 ... Substrate, 16 ... CCD camera, 17 ... Substrate warpage Correction means, 18 ... substrate suction jig, 19 ... camera X-axis moving frame.

Claims (4)

Substrate carry-in conveyor, substrate carry-out conveyor, X-axis, Y-axis and θ-axis moving mechanism and lifting mechanism, mask having transfer pattern as opening, and positioning provided on substrate and mask In a screen printing machine provided with a camera for imaging a mark, a squeegee, a squeegee head having a squeegee lifting mechanism and a horizontal movement mechanism, and a control device for controlling these mechanisms,
A screen printing machine, wherein a substrate warp correction means capable of moving up and down is provided on a camera X-axis moving frame for moving the camera and positioning an imaging position.   2. The screen printing machine according to claim 1, wherein the substrate warp correction means is provided so as to be movable in the Y-axis direction on the camera X-axis frame.   The substrate warp correction means includes an upper and lower cylinder, a relay plate attached to the tip of the upper and lower cylinders, a substrate pressing plate, and a substrate pressing plate mounting bracket, and fixes the substrate pressing plate and the relay plate via the substrate pressing plate mounting bracket. The screen printing machine according to claim 1, wherein the screen printing machine is configured. 4. The screen printing machine according to claim 3, wherein the substrate pressing plate is made of conductive plastic.

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