WO2014103032A1

WO2014103032A1 - Screen printer

Info

Publication number: WO2014103032A1
Application number: PCT/JP2012/084141
Authority: WO
Inventors: 陽司藤田; 祥史深草; 裕司勝見
Original assignee: 富士機械製造株式会社
Priority date: 2012-12-28
Filing date: 2012-12-28
Publication date: 2014-07-03
Also published as: JPWO2014103032A1; JP6063483B2

Abstract

The present invention improves the usefulness of monitoring that is performed on the basis of images taken by cameras in a screen printer. A camera (150) is installed on a mask frame bracket (40) of a mask-holding device (16) and takes images of a mask (46) and squeegees (122) from the side. A camera (160) is installed on the section of a squeegee slide (70) between a pair of squeegees (122) and cameras (162, 164) are installed on both sides of the pair of squeegees (122). Imaging by the camera (150) confirms the attachment/non-attachment, variety, etc. of the squeegees (122). Imaging by the camera (160) acquires the residual amount of solder by acquiring the diameter of the solder roll. Imaging by the cameras (162, 164) detects unscraped solder remaining on the mask (46) or insufficient filling of solder into through holes and prevents the occurrence of printing failures by executing an alarm to the worker, automatic solder replenishment, etc.

Description

Screen printing machine

The present invention relates to a screen printer, and more particularly to monitoring of a screen printer by a camera.

The following Patent Document 1 describes monitoring of the operation status of a printing facility using a camera and a microphone. The operation status is acquired for each predetermined inspection date and time, is databased together with the quality / operation information of the printing process output from the printing facility, and is used for analyzing the relationship between the failure tendency and the maintenance method.

JP-A-9-102700

The present invention has been made under the above circumstances, and an object thereof is to improve the practicality of monitoring performed based on imaging by a camera in a screen printing machine.

The above-mentioned subject is a cover of a screen printing machine that pushes paste solder placed on a screen mask along the screen mask with a squeegee and prints it on a circuit substrate through a plurality of through holes formed in the screen mask. This is solved by providing a camera in the internal space covered by the image, causing the imaging target set in the screen printing machine to be imaged, and displaying the captured image on the monitor.
For example, (a) a printed wiring board on which an electronic circuit component is not yet mounted, (b) an electronic circuit component is mounted on one surface and electrically connected to the circuit substrate, and the other surface is A printed circuit board on which no electronic circuit component is mounted, (c) a base material on which a bare chip is mounted and constituting a substrate with a chip, (d) a base material on which an electronic circuit component having a ball grid array is mounted, (e ) Substrates having a three-dimensional shape rather than a flat shape are included.

By providing a camera inside the screen printing machine and imaging a preset imaging target, the state of the monitoring target can be grasped in the vicinity thereof.

It is a perspective view which shows the screen printer which is one Embodiment of this invention. It is a side view which shows the squeegee apparatus etc. of the said screen printer. It is a top view which shows the mask holding | maintenance apparatus of the said screen printer. It is a front view which shows roughly the squeegee head of the said squeegee apparatus, and a squeegee raising / lowering apparatus. It is a side view which shows the solder supply apparatus of the said screen printer. It is a side view (partial cross section) which shows the camera provided in the squeegee slide of the said screen printing machine with a squeegee head. It is a block diagram which shows the control apparatus of the said screen printer. It is a perspective view which shows the state by which the image obtained by the imaging of the camera attached to the said mask holding | maintenance apparatus was displayed on the monitor for cameras.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the present invention can be implemented in a mode in which various modifications are made based on the knowledge of those skilled in the art, in addition to the following embodiments.

FIG. 1 shows a screen printing machine (hereinafter abbreviated as a printing machine) according to an embodiment of the present invention. This printing machine is configured in the same manner as the printing machine described in Japanese Patent Application Laid-Open No. 2011-230353 except for the part related to the present invention, and will be briefly described. As shown in FIG. 2, the printing machine includes a printing machine main body 10, a substrate conveying device 12 that is a substrate conveying device, a substrate holding device 14 that is a substrate holding device, a mask holding device 16, a squeegee device 18, and a solder supply device 20. And a control device 22 (see FIG. 7).

The substrate transport device 12 is configured by a belt conveyor in the present embodiment, and transports a circuit substrate 30 (hereinafter abbreviated as a substrate 30), which is a kind of circuit base material, in a horizontal posture. In the present embodiment, “circuit board” is a general term for a printed wiring board and a printed circuit board. Further, in this specification, the substrate transport direction which is the transport direction of the substrate 30 is a left-right direction or a width direction, and a direction orthogonal to the substrate transport direction is a front-rear direction. In the present embodiment, both the left-right direction and the front-rear direction are horizontal. The substrate holding device 14 is provided in the substrate transport direction of the substrate transport device 12, includes a substrate support device and a substrate clamp device, and is lifted and lowered by the lift device 32.

The mask holding device 16 is provided above the substrate transfer device 12 as shown in FIG. As shown in FIG. 3, the mask holding device 16 includes a pair of mask frame receivers 40, a mask fixing device 42, and a position adjusting device 44, and holds a screen mask 46 (hereinafter abbreviated as mask 46) in a horizontal posture. To do. The mask 46 is made of a metal, for example, stainless steel sheet, and is stretched on the mask frame 48. In the printing range 50 of the mask 46, a plurality of through holes 56 are formed so as to open on the upper surface 52 and the lower surface 54 (see FIG. 6) of the mask 46.

Each of the pair of mask frame receivers 40 receives the mask frame 48 from below by a horizontal receiving portion 58 as shown in FIG. The mask frame 48 is fixed to the receiving portion 58 by the mask fixing device 42. The position adjusting device 44 moves the mask frame receiver 40 to adjust the relative position between the mask 46 and the substrate 30 and eliminates the relative displacement between them.

As shown in FIG. 2, the squeegee device 18 includes a squeegee device body 60, a pair of squeegee heads 62, a squeegee moving device 64, and a pair of squeegee lifting devices 66 (one squeegee lifting device 66 is shown in FIG. 4). The squeegee device main body 60 is fixed to the upper surface of the mask frame receiver 40. When adjusting the position, the squeegee device 18 is moved with respect to the substrate 30 together with the mask 46. The squeegee moving device 64 includes a squeegee slide 70 and a squeegee slide driving device 72 that are movable members. The squeegee slide drive device 72 in this embodiment includes a plurality of pulleys 74, a belt 76 wound around the pulleys 74, and an electric motor 78 that rotationally drives one of the plurality of pulleys 74, and guides the squeegee slide 70. The guide rod 82 as a member is moved in the front-rear direction while being guided. As the pulley 74 and the belt 76, a timing pulley and a timing belt are suitable, and as the electric motor 78, an electric motor capable of controlling the rotation angle such as a servo motor is suitable. The same applies to the following pulleys, belts and electric motors.

The squeegee lifting device 66 is provided on the squeegee slide 70 as schematically shown in FIG. 4, and includes a lifting member 90 and a lifting member driving device 92. The squeegee slide 70 is provided with another elevating member 94 that can be moved up and down, and is biased by a tension coil spring 96 in a direction approaching the squeegee slide 70. A load cell 98 as a load detector and a compression coil spring 100 are provided between the squeegee slide 70 and the elevating member 94, and the pressing force of the squeegee against the mask 46 is detected. The

coil springs

96 and 100 are a kind of spring as an elastic member which is a kind of urging means. The elevating member 90 is held by the elevating member 94 so as to be movable up and down. The elevating member driving device 92 includes an electric motor 102 (see FIG. 7) as a driving source, and a feed screw mechanism 108 including a feed screw 104 and a nut 106. As the feed screw 104, a ball screw is suitable. The feed screw 104 is fixedly attached to the elevating member 90, and the nut 106 is attached to the elevating member 94 so as to be rotatable and immovable in the axial direction, and is screwed to the feed screw 104. The rotation of the electric motor 102 is transmitted to the nut 106 by a plurality of pulleys including a pulley 110 fixed to the nut 106 and a belt wound around the pulleys. When the nut 106 is rotated by the electric motor 102, the elevating member 90 is raised and lowered with respect to the elevating member 94 while being guided by the guide rod 112 serving as a guide member. One lifting member 94 is provided for each lifting member 90 of the pair of squeegee lifting devices 66 and is shared by the two lifting members 90.

Each of the pair of squeegee heads 62 includes a squeegee holding member 120 and a squeegee 122 as shown in FIG. 2, and one of them is detachably attached to the elevating member 90 as shown in FIG. The squeegee 122 has a longitudinal plate shape, the longitudinal direction of which is parallel to the width direction of the printing press, and as shown in FIG. It is held by the squeegee holding member 120 in the posture. The squeegee 122 is moved in the front-rear direction by the squeegee moving device 64. The front-rear direction is the printing direction, and the substrate transport direction and the printing direction are perpendicular to each other in this printing machine. There are a plurality of types of squeegees 122 that differ in at least one of the width and the material. A squeegee 122 having a width corresponding to the width of the substrate 30 is used. The width of the squeegee 122 and the width of the substrate 30 are both dimensions in a direction parallel to the width direction of the printing press. The squeegee 122 is made of, for example, metal or rubber.

The solder supply device 20 is mounted on a squeegee slide 70 as shown in FIG. The solder supply apparatus 20 includes a solder container 130 as shown in FIG. The solder container 130 is provided on the squeegee slide 70 so as to be rotatable around an axis parallel to the printing direction and movable in the width direction of the printing press. The solder container 130 is rotated by the container rotating device 132 to be at a right angle with respect to the mask 46, and moved toward the mask 46 while being moved in the width direction of the printing press by the container moving device 134. Paste solder (hereinafter abbreviated as solder) is discharged.

The printing press is covered with a cover 140 as shown in FIG. The cover 140 includes a pair of side walls, a top wall, a front wall, and a rear wall, and is attached to the outside of the printing press main body 10 to cover the entire printing press. The substrate transfer device 12 and the like are provided in the internal space covered by the cover 140, and a camera 150 is installed as shown in FIG. In this embodiment, the camera 150 has the mask 46 from the side, that is, in the printing direction, at an intermediate portion parallel to the printing direction of one vertical side wall 148 of the pair of mask frame receivers 40. It is attached in a direction to capture an image from a horizontal direction at a right angle. In this embodiment, the camera 150 includes a zoom lens, and can capture an image of the entire print area, which is an area in which the squeegee 122 moves on the mask 46, and an image obtained by enlarging a part thereof. The camera 150 is also capable of capturing moving images.

The imaging direction of the camera 150 is changed by the swinging device 152 shown in FIG. Although detailed illustration is omitted, the head swing device 152 uses an electric motor as a drive source in the present embodiment, and rotates the camera 150 about a vertical axis perpendicular to the mask 46. The head swing device may rotate the camera around an axis parallel to the printing direction and parallel to the mask 46. The camera 150 may be swung manually by an operator.

A lighting device 154 is provided in the vicinity of the camera 150. The lighting device 154 is switched between an on state and an off state by an operator operating the lighting switch 156. As shown in FIG. 1, the illumination switch 156 is provided on the front surface of the outer surface of the cover 140. In this embodiment, the illumination device 154 is kept on while the operator is turning on, and the operator operates the illumination switch 156. If not, the lighting device 154 is returned to the off state.

As shown in FIG. 2, the eyelid camera 150, the swinging device 152, and the lighting device 154 are attached to the attachment member 158 and attached to the side wall 148 via the attachment member 158. The attachment member 158 can be changed to a plurality of attachment positions in a direction parallel to the printing direction with respect to the side wall 148. In the present embodiment, these positions are discontinuous positions at an appropriate interval, for example, positions at equal intervals. The position of the attachment member 158 is changed by the operator, the position of the camera 150 is changed, and the imaging target is changed. The position of the camera 150 may be continuously changed, may be changed in a direction perpendicular to the mask 46, or may be moved by a moving device having a power source. Making it possible to change the position in the direction parallel to the printing direction of the camera is effective, for example, when a plurality of printing areas are provided in one mask. When multiple print areas are provided at different positions in the direction parallel to the print direction and are used selectively for printing, a camera is attached at a position corresponding to the print area used, and the print state is imaged from the side. Can do.

As shown in FIG. 2,

cameras

160, 162, and 164 are mounted on the squeegee slide 70 and are moved in a direction parallel to the mask 46 together with the squeegee 122. In the present embodiment, the squeegee moving device 64 also serves as a camera moving device, and the printing press is configured simply and inexpensively. The camera 160 is provided in a portion between the pair of squeegee heads 62 of the squeegee slide 70. The

cameras

162 and 164 are provided on both sides of the pair of squeegees 122 in the printing direction of the squeegee slide 70, respectively. In the present embodiment, the

cameras

160, 162, and 164 are provided downward in the center in the width direction of the squeegee slide 70 (direction parallel to the width direction of the printing press). In this embodiment, the

cameras

160, 162, and 164 have a wide angle and a deep depth of field, and can capture a moving image, and the mask 46 can be imaged in the entire width direction. The

cameras

160, 162, and 164 may be configured such that the imaging direction can be changed by the swing device similarly to the camera 150, and the imaging range can be expanded or reduced.

As shown in FIG. 1, an operation monitor 170 is provided on the upper front surface of the cover 140, and a camera monitor 172 is provided on the lower front surface. The operation monitor 170 displays data, various input guides, questions, etc. on the screen, and allows the operator to input data, instructions, etc. by touching the screen. The operation device, input device, display device Configure. The camera monitor 172 displays an image obtained by imaging with the camera 150. The camera monitor 172 is provided outside the cover 140 and is visible to a person outside the cover 140.

As shown in FIG. 7, the control device 22 is mainly configured by a computer 180 including a CPU, a RAM, a ROM, and an I / O port, and various detection devices and operation devices are connected to the computer 180. Of these, the computer 180 is closely related to the present invention, but the computer 180 controls the drive source of the operating device such as the substrate transfer device 12 and the warning device 184 via the drive circuit 182, and controls the

control circuits

185 and 186. The operation monitor 170 and the camera monitor 172 are controlled via this. The warning device 184 issues a warning by, for example, sounding a buzzer or lighting or blinking a lamp. The computer 180 is also connected with a load cell 98, a lighting switch 156, and an image data storage device 188, and

cameras

150, 160, 162, and 164 are connected via a control / image processing device 190. The control / image processing apparatus 190 is mainly composed of a computer. An image data memory may be provided in the RAM of the computer 180 as an image data storage device.

At the time of printing in the printing machine configured as described above, the substrate 30 is carried in by the substrate transport device 12, stopped at a predetermined position, and then held by the substrate holding device 14. Then, the reference marks provided on the substrate 30 and the mask 46 are imaged by a reference mark imaging device (not shown), and the position adjustment device 44 aligns the mask 46 and the substrate 30. At this time, the relative positions of the camera 150 attached to the mask frame receiver 40, the mask 46, and the squeegee device 18 do not change. The relative positions of the

cameras

160, 162, 164 and the mask 46 are not changed.

After the position adjustment, the substrate holding device 14 is raised by the lifting device 32, and the substrate 30 is brought into contact with the lower surface 54 of the mask 46. Then, one of the pair of squeegees 122 is lowered and moved while being in contact with the mask 46, the solder placed on the mask 46 is pushed along the mask 46, and is pushed into the through-hole 56. 30. The solder is rolled on the mask 46 by the squeegee 122 to form a roll as shown in FIG. Hereinafter, this roll-shaped solder is referred to as a solder roll 200. After printing, the substrate 30 is lowered and separated from the mask 46, released from being held by the substrate holding device 14, and carried out. The pair of squeegees 122 are alternately brought into contact with the mask 46, and the solder roll 200 is pushed to perform printing.

As described above, when solder printing is performed on the substrate 30 in the printing machine, the

cameras

150, 160, 162, and 164 always perform imaging, and the imaging data is processed and analyzed by the control / image processing apparatus 190. The image data of the

cameras

150, 160, 162, and 164 differ depending on the camera installation position and imaging direction, and are used for purposes suitable for each in the present embodiment.

The entire printing area is imaged by the camera 150, and the upper surface 52 of the mask 46, the pair of squeegees 122, the solder roll 200, and the like are imaged. Therefore, the image data obtained by the imaging of the camera 150 is sent from the control / image processing apparatus 190 to the computer 180 and displayed on the camera monitor 172 in parallel with the imaging as illustrated in FIG. The operator can check the printing state by looking at the displayed image. For example, the operator checks the holding state of the squeegee 122 by the squeegee holding member 120, the scraping state of the solder on the upper surface 52, the rolling state of the solder roll 200, the remaining amount of solder, and the filling state of the solder in the through hole 56. . The internal space of the cover 140 can be observed from outside the cover 140 by providing a transparent window on the cover 140, but it is difficult to see because of the distance. On the other hand, according to the camera 150 provided in the internal space, the mask 46, the solder roll 200, and the like can be imaged nearby, and the operator can clearly check their state. In particular, since the camera 150 captures images of the squeegee 122 and the like from the side, the state in which the solder roll 200 is pushed by the squeegee 122 and the solder roll 200 are compared with the case of capturing images from the front and back (from the direction parallel to the printing direction). It is easy to check the rolling state. About the rolling state of the solder roll 200, it is confirmed whether there is no dent in an outer peripheral surface and the solder has comprised the roll shape neatly. Further, depending on the position of the squeegee 122 in the printing direction, the entire back surface that is the surface opposite to the contact surface or the feeding surface that is brought into contact with the solder roll 200 is imaged and can be observed by the operator. By providing the camera monitor 172 separately from the operation monitor 170, the captured image can be displayed at all times and can be observed by the operator. However, the captured image data may be displayed on part or all of the operation monitor 170, and the operation monitor 170 may also serve as the camera monitor.

If the observation object is a shadow of the squeegee 122 or the squeegee slide 70 and the image is dark and difficult to see, the operator turns on the illumination switch 156 to cause the illumination device 154 to illuminate the imaging region of the camera 150. The object can be brightened and the object can be observed clearly. Since the illumination device 154 performs illumination only while the illumination switch 156 is turned on, there is no extra illumination, and a problem due to prolonged illumination due to forgetting to turn off, for example, the illumination device 154 It is possible to prevent an increase in the ambient temperature in the printing press due to heat generation of the ink and a change in viscosity due to evaporation of the liquid contained in the solder, such as flux. The lighting device 154 may be turned on / off by an operator inputting an instruction using the operation monitor 170.

In addition, the operator inputs the focal length of the zoom lens of the camera 150 using the operation monitor 170, causes the control / image processing device 190 to control the camera 150, and enlarges or reduces the imaging range for imaging. Can do. Thereby, an image having a desired size for the observation target can be displayed on the camera monitor 172 and observed. In the present embodiment, the operation monitor 170 constitutes an enlargement / reduction command device.

Furthermore, the imaging direction of the camera 150 can be changed by the swing device 152, and in this embodiment, imaging is performed with the imaging direction fixed in the changed direction. In the present embodiment, the swing angle is 0 degree, and the direction of the center line of the swing range is changed. The imaging direction of the camera 150 is input by the operator using the operation monitor 170, and the swinging device 152 is operated based on the input direction to rotate the camera 150. In the present embodiment, the operation monitor 170 constitutes a swing operation device. The swing angle may be greater than 0 degrees, in which case the imaging direction of the camera is changed within the swing range during imaging. Further, when the direction of the center line of the swing range can also be changed, the swing during imaging is performed within the swing range centered on the changed center line.

The image data sent from the control / image processing device 190 is always stored in the image data storage device 188 together with image-related data, for example, the date and time and the substrate identifier of the substrate 30. Thereby, traceability in which the operator can see the print state after printing is obtained. For example, when a defect occurs in the subsequent process, the printing press is stopped, and recorded data for a set time until the defect occurs is reproduced and displayed on the camera monitor 172. Reproduction and display may be performed automatically or based on an operator's instruction. The operator may look at the display to check the state of the solder roll 200 when the solder printing is performed on the substrate 30 in which the defect has occurred, the state of the solder scraped by the squeegee 122, and the like to find the cause of the defect. it can.

Further, by analyzing the image data obtained by the imaging of the camera 150, for example, the presence or absence of the squeegee 122, the suitability of the dimensions of the squeegee 122, and the presence or absence of wrinkles on the upper surface 52 of the mask 46 are detected. In a state where the squeegee 122 is positioned at the print start position or the print end position, the camera 150 can capture the entire squeegee 122 and the width of the squeegee 122 can be acquired. The analysis result is sent to the computer 180, and if there is a problem, processing corresponding to that is performed. Also, execution of printing is prohibited. For example, if there is no squeegee 122, the warning device 184 notifies the worker. At the same time, the contents of the defect are displayed on the operation monitor 170. The operation monitor 170 can also function as a warning device. Further, the width of the squeegee 122 is compared with the width of the squeegee 122 scheduled to be used, and it is determined whether or not the planned squeegee 122 is being used. If the wrong type of squeegee 122 is used, a warning is issued. Further, if the upper surface 52 of the mask 46 is wrinkled, the mask 46 that should not be used is attached, and it is assumed that a mask setting error has occurred, and a warning is issued. The operator solves the problem based on the warning. Imaging by the camera 150 may be performed before the start of printing, for example, from the time of setup change, and an installation error of the squeegee 122 may be detected and warned before the start of printing.

When the printing machine includes a warning device, it includes a warning release unit that confirms that some action has been taken by the worker in response to a warning from the warning device and releases the warning state by the warning device based on the confirmation. It is desirable that For this reason, in the present embodiment, the operator inputs that the warning has been acknowledged using the operation monitor 170, and the warning state is released based on confirmation that the input operation has been performed. It is supposed to be. In addition, the operator inputs the resolution of the problem using the operation monitor 170, and the printing press starts printing. The warning state may be canceled based on confirmation that the worker has performed necessary work in response to the warning.

Image data and analysis results obtained by imaging with the

cameras

160, 162, and 164 are sent from the control / image processing device 190 to the computer 180, and the image data is stored in the image data storage device 188. Used for. As shown in FIG. 6, the camera 160 is provided between the pair of squeegees 122 and images the solder roll 200 from above. The downstream edge in the printing direction of the solder roll 200 is imaged, the diameter of the solder roll 200 is acquired based on the position on the imaging surface, and the remaining solder amount is acquired. The remaining amount of solder is compared with the set amount in the computer 180. If the remaining amount is less than the set amount, the solder supplying device 20 is operated, and the solder is automatically supplied onto the upper surface 52. Thereby, it is possible to always perform printing with an optimal amount of solder. The solder supply device 20 constitutes a solder supply device. The acquisition of the remaining amount of solder can also be used as a solder supply advance notice function. For example, when the remaining amount is equal to or less than the set amount, it is scheduled that the solder supply will be performed after the solder printing on the set number of substrates 30 and the solder supply operation is performed by the squeegee device 18 and the solder supply device 20 after the printing. It is made to be. Alternatively, the operator is notified that solder replenishment is performed.

Of the pair of squeegees 122, the remaining solder amount may be acquired when the squeegee 122 used for printing is replaced. After the printed squeegee 122 is raised, it is moved in the printing direction, and the camera 160 moves the solder roll 200 while the squeegee 122 to be used next is moved to a position where it can contact the solder roll 200 in the printing direction. This is because the entire image can be taken by traversing in the direction perpendicular to the longitudinal direction (direction parallel to the width direction of the printing press).

Also, an image of the surface of the solder roll 200 is obtained by imaging with the camera 160, and the presence or absence of voids or foreign matter on the surface is detected. If a void or the like is detected, the warning device 184 is activated by the computer 180 and a warning is issued, and the operator performs a removal operation of the void or the like.

The

eyelid cameras

162 and 164 image the mask 46 from right above in a direction perpendicular to the upper surface 52. Of the

cameras

162 and 164, the camera positioned upstream in the printing direction of the squeegee 122 used for printing images the mask 46 after printing, and the camera positioned downstream captures the mask 46 before printing. Take an image. By imaging the mask 46 after printing, the solder filled in the through hole 56 is imaged, and the solder filling amount is detected. The solder filling amount is obtained, for example, by calculating a ratio of the filled solder in the through hole 56 in the top view. Alternatively, the solder filling amount may be acquired by comparing images captured by the two

cameras

162 and 164, respectively. This is because the image is changed by filling the through holes 56 with solder. For example, by evaluating the difference image between two images before and after printing, that is, by examining the difference in luminance value for each corresponding pixel in both images before and after printing, and extracting pixels with different luminance values before and after printing The amount of solder filled in the through hole 56 of the mask 46 can be acquired.

Also, the presence or absence of solder streaks on the upper surface 52 is detected by imaging the mask 46. Similar to the detection of the solder filling amount in the through hole 56, this detection may be performed only by imaging the mask 46 after printing, or a difference image between two images obtained by imaging the mask 46 before and after printing. It may be performed by evaluation.

In the computer 180, if there is a through-hole 56 that is not filled with solder at least in part, printing is defective, and for example, printing is performed again on the substrate 30 so that the insufficient filling amount is resolved. . For this reason, the substrate 30 is not separated from the mask 46, and the squeegee 122 is replaced and moved along the mask 46 to perform printing. When the inspection for insufficient solder filling is performed in a state where the substrate 30 is separated from the mask 46, the substrate 30 and the mask 46 are positioned when the substrate 30 is brought into contact with the mask 46 for reprinting after the inspection. The solder printed on the substrate 30 is made to enter the through hole 56. Therefore, the solder may adhere to the lower surface 54 of the mask 46 and become dirty, and it takes time to perform the positioning again and the raising / lowering operation of the substrate 30. On the other hand, insufficiency of solder filling is detected while the substrate 30 is kept in contact with the mask 46, and the second printing is performed, so that the lower surface 54 is not soiled. In addition, the time required for the second printing is shortened, and a reduction in work efficiency is suppressed. Furthermore, the positional accuracy of the solder printed at the second time relative to the solder printed at the first time is improved. If the print amount is still insufficient even after printing twice, a warning is issued by the warning device 184.

If there are solder streaks on the upper surface 52, it is considered that there is a residue of scraping of the solder, and the pressing force of the squeegee 122 to the mask 46 is increased. The pressing force when the squeegee 122 is pressed against the substrate 30 through the mask 46, that is, the reaction force applied to the squeegee 122 by the substrate 30 and the mask 46, is applied to the squeegee holding member 120, the elevating member 90, the elevating member driving device 92, It is transmitted to the load cell 98 via the member 94 and the compression coil spring 100, and its size is measured. When the pressing force is increased, the set value of the pressing force detected by the load cell 98 is increased and the descending distance of the squeegee 122 with respect to the mask 46 is increased, so that scraping defects are prevented. By dealing with defects based on the images taken by the

cameras

150, 160, 162, and 164, it is possible to improve printing quality and to improve the quality of work performed on the substrate 30 after printing, for example, mounting of electronic circuit components.

The images obtained by the images taken by the

camera

160, 162, 164 may also be displayed on the monitor. A monitor may be provided for each of the

cameras

160, 162, and 164, may be shared, and may be displayed on the camera monitor 172. When one monitor is also used for displaying images of a plurality of cameras, for example, the images of the respective cameras are displayed by switching or dividing the screen.

Image data obtained by imaging by the camera 160 can be used for an IPQC (In Process Quality Control) function or an SPC (Statistical Process Control). For example, when the work quality in the electronic circuit formation process for the substrate 30 is managed based on the inspection of the substrate 30 by the inspection machine, the image data is used to investigate the cause when the defect occurs. And the acquired cause can be solved and it can feed back to the working machine upstream from an inspection machine, and it can be made to prevent a defect. Alternatively, when the decrease in the remaining amount of solder is detected based on the image pickup by the camera 160, the

cameras

162 and 164 can be operated to acquire the solder filling state.

As is apparent from the above description, in the present embodiment, the control device 22 and the control / image processing device 190 constitute a monitoring control device. Further, the control device 22 constitutes a pressing force control device and a reprint command unit, and constitutes a main control device together with the solder supply device 20 and the warning device 184. Further, the control / image processing device 190 constitutes an image analysis device, and the control device 22 constitutes an image reproduction device.

In addition, since the camera 150 can image the upper surface 52 of the mask 46 and can image the side surface of the solder roll 200, the solder filling amount in the through hole 56 based on the image data obtained by the imaging, It is possible to detect the remaining amount of solder by removing the scraped solder. Therefore, it is possible to always cause only the camera 150 to take an image, and to cause the

cameras

160, 162, and 164 to take an image when the camera 150 breaks down. Alternatively, when imaging by at least one of the

cameras

160, 162, and 164 is required based on the imaging result of the camera 150, for example, an image from above the upper surface 52 of the solder roll 200 or the mask 46 is required. In this case, a camera that can obtain a necessary image may be caused to perform imaging. In order to detect the occurrence of voids and foreign matter contamination on the surface of the solder roll 200, the camera 160 and the camera 160 may be imaged.

It is not indispensable to provide all of the

cameras

150, 160, 162, and 164 in the printing press, and at least one may be provided.

The worker may check the print state by looking at the image displayed on the monitor, and if there is a problem, may give an instruction to resolve it. For example, the operator gives an instruction to increase the pressing force of the squeegee 122 against the mask 46 or to perform solder twice printing.

Also, the camera may be provided on the side of the mask, or alternatively, it may be provided at a place other than the side, for example, in front of the mask or on the back. Further, the camera is not limited to the periphery of the mask, but can be provided inside the printing machine at an appropriate position where the imaging target can be imaged. For example, at least one of an approach / separation state between the mask and the substrate, a state of the lower surface of the mask, a state of the through hole of the mask (cleaning state), an adjustment state of the relative position between the mask and the substrate, and an operating state of the solder supply device And a camera is provided at a position where imaging is possible. As a result, the inside of the printing press can be monitored without any blind spots, and malfunctions such as malfunctions can be detected early. As the camera, for example, various cameras such as a wide-angle camera with a deep depth of field, a camera that can expand and contract an imaging range, and a camera that can capture a moving image can be used.

The camera that images the squeegee etc. from the side may be moved in synchronization with the movement of the squeegee. In that case, the camera may be provided on the squeegee slide or may be moved by a moving device different from the squeegee moving device.

According to a second aspect of the present invention, the feature of the first aspect is that a camera installed in a state in which a solder roll can be imaged and a camera installed in a state in which an upper surface of a screen mask can be imaged. It can be employed independently of the feature of “including at least one”. The same applies to claims 3, 4, and 5.

46: Screen mask 122:

Squeegee

150, 160, 162, 164: Camera 172: Camera monitor

Claims

A screen printing machine that pushes paste solder placed on a screen mask along the screen mask with a squeegee and prints on a circuit substrate through a plurality of through holes formed in the screen mask,
The screen printing machine is covered by a cover, installed in an internal space covered by the cover, and a camera capable of capturing an image of a printing area in which the squeegee moves on the screen mask;
A monitor that is installed in a state where a person outside the cover can visually recognize the screen, and displays an image captured by the camera on the screen;
A screen printing machine connected to the camera and the monitor and including a monitoring unit control device for controlling the camera and the monitor;
As the camera, (a) a camera installed in a state in which a solder roll, which is paste-like solder being pushed by the squeegee, can be imaged, and (b) an upper surface of the screen mask after passing through the squeegee can be imaged. A screen printing machine comprising at least one of a camera installed in a state.
further,
An image analysis device for analyzing an image captured by the camera;
Based on the analysis result of the image analysis device, (a) a solder supply device for supplying paste solder onto the screen mask, (b) a pressing force control device for controlling the pressing force of the squeegee against the screen mask, c) a reprint command unit that operates the squeegee again without separating the screen mask from the circuit substrate when there is an insufficient amount of solder filling among the plurality of through holes of the screen mask; and The screen printing machine according to claim 1, comprising: d) at least one warning device that issues a warning to an operator, and a main control device that controls the screen printing machine.
The screen printing machine according to claim 1, further comprising a camera moving device that moves the camera in a direction parallel to at least the screen mask.
further,
A swing device capable of changing the imaging direction of the camera, and provided at the outside of the screen printing machine, for setting at least one of the swing angle of the swing device and the direction of the center line of the swing range A swing operation device operable to
4. The camera according to claim 1, wherein the camera is capable of enlarging / reducing an imaging range, and includes at least one of an enlargement / reduction command device provided outside the screen printing machine and capable of commanding the enlargement / reduction of the imaging range. The screen printing machine described in 1.
further,
An image data storage device for storing data of an image captured by the camera;
The screen printing machine according to claim 1, further comprising: an image reproduction device that displays an image based on the image data stored in the image data storage device on the monitor as necessary.