JP3928535B2 - Screen printing apparatus and screen printing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screen printing apparatus and a screen printing method for printing paste such as cream solder or conductive paste on a substrate.
[0002]
[Prior art]
In mounting electronic components, cream solder is applied to the surface of the substrate prior to mounting the electronic components on the substrate. As a method for applying the cream solder, a screen printing method is widely used, and after the printing process, a printing inspection for inspecting the printing state of the cream solder is performed.
[0003]
This print inspection is to determine whether or not the cream solder is correctly printed on the printed part by picking up an image of the substrate after screen printing with a camera and performing image recognition processing on the image pickup result. Inspection results are output for inspection items such as “bleeding” that is excessively large in the print amount and “bleed” that protrudes outward from the print range and “blur” that is excessively small in the print target portion.
[0004]
These inspections are generally performed by comparing inspection quantities such as a print area calculated by image recognition processing with a preset inspection threshold value, and pass / fail judgment is made with the inspection threshold as a boundary. The Along with this, for predetermined inspection items, data for determining the necessity of a predetermined feedback operation by determining the calculated inspection quantities for purposes other than the pass / fail determination, for example, the tendency of specific items in the printing state It has come to be used as.
[0005]
[Patent Document 1]
JP 2002-19071 A
[0006]
[Problems to be solved by the invention]
However, in conventional screen printing, there are only examples in which the various amounts of inspection required in the print inspection process are used for the mask plate cleaning operation (see, for example, JP-A-2002-19071 (0041)), It could not be said that the required amount of inspection was effectively utilized, and the usefulness of printing inspection was not sufficiently ensured.
[0007]
Therefore, an object of the present invention is to provide a screen printing apparatus and a screen printing method that can effectively use various inspection quantities obtained in a print inspection and improve the usefulness of the print inspection.
[0008]
[Means for Solving the Problems]
The screen printing apparatus according to claim 1, wherein the substrate is brought into contact with a mask plate provided with a pattern hole, a paste is supplied onto the mask plate, and a squeegee is slid to the substrate through the pattern hole. A screen printing apparatus for printing a paste, a substrate positioning mechanism for positioning the substrate relative to a mask plate, positioning control means for controlling the substrate positioning mechanism based on positioning data, and a mask for the squeegee A squeegee moving means for moving on a plate, a printing position storing means for storing positioning data for each substrate when printing is performed for each substrate, and a print target portion with respect to a printing state of the paste on the printed substrate "Bludge" where the paste protruded from the print area and A print inspection means that performs a print inspection in which an inspection item includes “faint” with an excessively small printing amount, and outputs a determination result based on a predetermined inspection threshold value for the inspection item, Overprint printing execution determination means for determining whether or not to execute overprint printing for printing a paste again for the purpose of improving the state of "" based on the inspection result by the print inspection means A cleaning operation for determining that a cleaning operation of the lower surface of the mask plate by the cleaning unit is executed prior to the overprinting when all the inspection results by the printing inspection means are acceptable but tend to be “blurred” Execution judgment means And with.
[0010]
Claim 2 The screen printing apparatus as claimed in claim 1 The screen printing apparatus according to claim 1, further comprising mode setting means for presetting a work operation mode that combines execution / non-execution of the overprint printing and execution / non-execution of the cleaning operation during automatic operation.
[0011]
Claim 3 The screen printing method described is such that a mask plate provided with a pattern hole is brought into contact with the substrate, a paste is supplied onto the mask plate, and a squeegee is slid to print the paste on the substrate through the pattern hole. In the screen printing method, the print status of the paste on the printed board is set to inspection items of “bleeding” in which the paste protrudes from the print range in the print target portion and “blur” in which the print amount in the print target portion is too small. A print inspection process that performs a print inspection and outputs a determination result based on a predetermined inspection threshold for the inspection item, and an overlay that prints the paste again for the purpose of improving the “blurred” state on the printed substrate Overprint printing execution determination process for determining whether or not to perform printing printing based on the inspection result of the printing inspection process And, If all of the inspection results in the print inspection process are acceptable, but tend to be `` blurred '', a step of performing a cleaning operation of the lower surface of the mask plate by the cleaning unit prior to overprinting, and And an overprint printing step of printing a paste by bringing the substrate determined to be overprint printing into contact with the mask plate again.
[0013]
Claim 4 The screen printing method described in claim 3 In the screen printing method described above, a work operation mode that combines execution / non-execution of the overprint printing and execution / non-execution of the cleaning operation during automatic operation is set in advance.
[0014]
According to the present invention, the print state of the paste on the printed substrate is subjected to a print inspection for inspection items including “bleeding” in which the paste protrudes from the print target portion and “blur” in which the print amount at the print target portion is too small. Based on the inspection result of the print inspection, it is determined whether or not to perform overprint printing that prints the paste again for the purpose of improving the “blur” state on the printed circuit board. If all the inspection results are acceptable, but all tend to “smear”, the cleaning unit performs a cleaning operation on the lower surface of the mask plate prior to the overprinting. By doing so, it is possible to effectively utilize the various quantities required for the print inspection and to ensure the usefulness of the print inspection.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the screen printing apparatus according to an embodiment of the present invention, and FIG. 3 is a screen printing apparatus according to an embodiment of the present invention. FIG. 4 is a block diagram showing the configuration of the control system of the screen printing apparatus according to the embodiment of the present invention. FIG. 5 is a program storage unit and data storage unit of the screen printing apparatus according to the embodiment of the present invention. FIG. 6 is a diagram showing inspection threshold data of the screen printing apparatus according to the embodiment of the present invention. FIG. 7 is a diagram illustrating a printing failure state in the screen printing according to the embodiment of the invention. FIG. 8, FIG. 8 is a diagram showing a display screen of a screen printing apparatus according to an embodiment of the present invention, and FIGS. 9, 10, 11, and 12 are operation flowcharts of a screen printing method according to an embodiment of the present invention. It is.
[0016]
First, the structure of the screen printing apparatus will be described with reference to FIGS. 1 and 2, the screen printing apparatus is configured by disposing a screen printing unit 10 above the substrate positioning unit 1. The substrate positioning unit 1 is configured by stacking a Y-axis table 4, an X-axis table 5, and a θ-axis table 6, and further placing a Z-axis table 7 thereon. On the Z-axis table 7, there is provided a substrate holding unit 8 that holds the substrate 9 by being clamped by a clamper 8a. The board 9 is carried in by the carry-in conveyor 15A, and the printed board 9 is carried out by the carry-out conveyor 15B.
[0017]
A screen printing unit 10 is disposed above the substrate positioning unit 1. The screen printing unit 10 includes a mask plate 12 extended on a holder frame 11. A squeegee unit 13 is disposed on the mask plate 12, and the squeegee unit 13 is moved in the Y direction by squeegee moving means (not shown). A squeegee lifting mechanism 13 b is provided on the plate 13 a of the squeegee unit 13, and the squeegee lifting mechanism 13 b moves the squeegee 14 up and down with respect to the mask plate 12.
[0018]
With the substrate 9 in contact with the lower surface of the mask plate 12, the squeegee 14 is slid on the mask plate 12 to which the cream solder S as paste is supplied, thereby passing through the pattern holes 12a (see FIG. 3). The cream solder S is printed on each print target portion of the substrate 9. In this printing operation, by driving the substrate positioning unit 1 (substrate positioning mechanism), the substrate 9 held by the substrate holding unit 8 is positioned relative to the mask plate 12 and aligned with a predetermined printing position. Is done.
[0019]
Next, the cleaning unit will be described. In FIG. 2, a cleaning unit 2 is disposed on the side of the substrate positioning unit 1. A slider 21 is provided on the lower surface of the main body 20 of the cleaning unit 2, and the slider 21 is slidably fitted to the guide rail 4 a of the Y-axis table 4 of the substrate positioning unit 1. The cleaning unit 2 is movable in the Y direction orthogonal to the substrate transport direction.
[0020]
The cleaning unit 2 includes a supply reel 24 and a take-up reel 25 for the cleaning tape 23. The cleaning tape 23 fed from the supply reel 24 wraps around the upper surface of a cleaning head 26 provided on the upper surface of the main body 20 so as to be movable up and down and is taken up by the take-up reel 25. When the cleaning unit 2 is positioned below the screen printing unit 10 and the cleaning head 26 is raised, the cleaning tape 23 is pressed against the lower surface of the mask plate 12 to be cleaned. In this state, the lower surface of the mask plate 12 is cleaned by moving the cleaning unit 2 in the Y direction.
[0021]
In addition, by providing the suction portion in the cleaning head 26, the cream solder remaining in the pattern hole 12a of the mask plate 12 without being transferred to the substrate during printing can be sucked and removed. That is, the cleaning unit 2 is a cleaning unit that performs a cleaning operation for removing the cleaning solder remaining on the lower surface of the mask plate 12 and / or the pattern holes 12a.
[0022]
A cylinder 22 is disposed on the side surface of the main body portion 20 on the substrate positioning portion 1 side. The cylinder 22 is a double-rod type cylinder having rods that project in both the upper and lower directions. In the state shown in FIG. 2, the upper rod 22a is submerged and the lower rod 22b projects. In this state, the lower end portion of the lower rod 22b presses the base surface, whereby the position of the cleaning unit 2 is fixed. At this time, since the cylinder 22 is provided in the cleaning unit 2 which is a cleaning means, the position of the cleaning unit 2 can be fixed at an arbitrary position.
[0023]
The X-axis table 5 of the substrate positioning unit 1 is provided with a connecting member 5a, and the connecting member 5a is provided with a connecting hole 5b into which the upper rod 22a is fitted. By driving the Y-axis table 4 to move the substrate positioning unit 1, the connecting member 5 a is positioned above the cylinder 22, and the upper rod 22 a is protruded with the connecting hole 5 b aligned with the upper rod 22 a. The upper rod 22a is fitted into the connecting hole 5b. As a result, the cleaning unit 2 is connected to the substrate positioning unit 1 and the lower rod 22b is simultaneously immersed, whereby the cleaning unit 2 is unlocked. By this connection, the cleaning unit 2 can be moved to a desired Y-direction position by the substrate positioning unit 1.
[0024]
A camera 18 is provided above the screen printing unit 10. As shown in FIG. 3, the camera 18 is horizontally moved in the XY directions by the X-axis table 17 and the Y-axis table 16. The X axis table 17 and the Y axis table 16 serve as camera moving means for moving the camera 18. By moving the camera 18 with respect to the mask plate 12 by the camera moving means, the camera 18 images an arbitrary position of the mask plate 12.
[0025]
As shown in FIG. 2, the substrate positioning unit 1 is moved in the Y direction from below the screen printing unit 10 by the Y-axis table 4 so that the held substrate 9 can be moved to the substrate recognition position. In this state, by moving the camera 18 to the substrate 9 on the substrate positioning unit 1, an arbitrary position of the substrate 9 can be imaged by the camera 18.
[0026]
Next, the configuration of the control system of the screen printing apparatus will be described with reference to FIG. In FIG. 4, a calculation unit 30 is a CPU, and performs various calculations and processing described later by executing various programs stored in the program storage unit 31. In these calculations / processes, various data stored in the data storage unit 32 are used.
[0027]
The operation / input unit 33 is input means such as a keyboard and a mouse, and inputs various control commands and data. The communication unit 34 exchanges data with other devices constituting the electronic component mounting line together with the screen printing device. The image processing unit 35 performs image processing on image data obtained by imaging the substrate 9 with the camera 18, thereby recognizing a solder printing unit for print inspection as will be described later.
[0028]
The mechanism control unit 36 controls operations of the substrate positioning unit 1, the cleaning unit 2, and the screen printing unit 10. The display unit 37 is a display device. In addition to the image acquired by the camera 18 and the inspection result of the print inspection, as will be described later, the feedback operation is automatically performed by referring to the inspection result of the print inspection during the automatic operation. An operation screen for setting a work operation mode for presetting execution / non-execution of is displayed.
[0029]
Next, programs and data stored in the program storage unit 31 and the data storage unit 32 will be described with reference to FIG. The program storage unit 31 stores various programs such as a printing operation program 31a, an image processing program 31b, a print inspection program 31c, and a feedback processing program 31d.
[0030]
The printing operation program 31 a is a program for a printing operation that controls the operations of the substrate positioning unit 1 and the screen printing unit 10 to print cream solder on the substrate 9. The image processing program 31b is printed on the print target portion of the substrate 9 by the image processing unit 35 performing recognition processing on the image of the substrate 9 after detecting the substrate position and printing based on the imaging result of the camera 18. This is a program for calculating various inspection quantities such as the area of the solder printing section.
[0031]
The print inspection program 31c is a program for inspecting the print state for each print target portion by comparing inspection quantities such as the area of the solder print portion calculated by the image processing unit 35 with an inspection threshold value. is there. Here, depending on the ratio with the regular solder printing area in the print target part, “blur” indicating that the print amount is excessively small, “smudge” indicating that the print amount is excessively large, and a position deviated from the normal print range. Inspection results are output for “position misalignment” in which the solder is printed on and “bridge” in which the solder is improperly connected between adjacent solder printing portions.
[0032]
The function realized by the image processing unit 35 and the calculation unit 30 executing the print inspection program 31c is to perform a print inspection including “smudge” and “blur” as inspection items, and perform a predetermined inspection on these inspection items. Print inspection means for outputting a determination result based on the threshold value is configured. Here, the determination based on the inspection threshold includes, as will be described later, a pass / fail determination indicating good / bad separation, and a warning determination indicating that it is desirable to take some measure although it is not determined to be defective. Yes.
[0033]
The feedback processing program 31d is a feedback operation that is selected and executed under a specific condition when the inspection result does not correspond to the failure determination but shows a certain tendency to shift to a failure in the above-described print inspection. Is a program that performs processing related to selection / execution. In the present embodiment, as the feedback operation, overprint printing is performed in which cream solder is printed again for the purpose of improving the “blurred” state on the printed substrate, and the mask plate is executed in the middle of performing the printing operation. Cleaning is set, and in automatic operation, these feedback operations can be selectively executed based on a work operation mode selected and set in advance. Thereby, an appropriate printing operation according to the printing difficulty level and characteristics of the substrate to be printed is realized.
[0034]
FIG. 8 shows an operation screen for setting the work operation mode. In FIG. 8, on the display screen 40 of the display unit 37, operation switches 41a and 41b for selecting whether or not cleaning after print inspection is executed as a feedback operation in automatic operation and similarly overlap after print inspection in automatic operation. Operation switches 42a and 42b for selecting whether or not to execute printing as a feedback operation are displayed.
[0035]
Here, by selecting each of the operation switches 41a, 41b, 42a, and 42b, a work operation mode during automatic operation is set in advance as described later. Therefore, the function realized by the arithmetic unit 30 executing the feedback processing program 31d is preset with a work operation mode that combines execution / non-execution of overprint printing and execution / non-execution of a cleaning operation during automatic operation. This is a mode setting means.
[0036]
Further, the function realized by the calculation unit 30 executing the feedback processing program 31d is whether or not to perform overprint printing for printing a paste again for the purpose of improving the “blur” state on a printed substrate. Overprinting printing execution determining means for determining whether the cleaning operation is performed on the mask plate 12 based on the inspection result by the printing inspection means. It has also become a thing.
[0037]
The data storage unit 32 stores mounting data 32a, a component data library 32b, print position data 32c, and inspection threshold data 32d. The mounting data 32a is data used in a mounting operation for mounting an electronic component on a substrate after cream solder printing, that is, data in which the type of electronic component to be mounted is associated with mounting position coordinates on the substrate. The component data library 32b is data relating to individual electronic components mounted on the board.
[0038]
The printing position data 32c is positioning data indicating the coordinate values of the X, Y, and θ axes when each loaded substrate is positioned with respect to the mask plate 12 by the substrate positioning unit 1, and is stored for each substrate. The Then, the mechanism control unit 36 controls the substrate positioning unit 1 based on the read print position data, so that the substrate once released after printing can be aligned again at the same position as when printing is performed. It has become. That is, the data storage unit 32 is a printing position storage unit that stores positioning data for each substrate when a single substrate is positioned and printed, and the mechanism control unit 36 uses the substrate positioning unit 1 as positioning data. Positioning control means for controlling based on the above.
[0039]
The inspection threshold data 32d is threshold data for performing pass / fail determination and necessity determination of feeder back operation for each inspection item for each print target part in the print inspection. As shown in FIG. 6, the inspection threshold data includes numerical data for each type of electrode as a print target portion for each item of “blur”, “smear”, “position shift”, and “bridge”. Yes.
[0040]
Here, these inspection items will be described with reference to FIG. FIG. 7A shows a “positional shift” in which the position of the cream solder S printed with respect to the regular printing range a is shifted. Further, FIGS. 7B and 7C show “blur” in which the printing amount of the cream solder S in the printing range “a” (substituting the printing area) is excessive, and conversely, the printing amount of the cream solder S is excessive. “Bludge” printed out of the print range a is shown. FIG. 7D shows a “bridge” in which the cream solder S is connected between two adjacent print areas a.
[0041]
Among these numerical data, for “blur” and “smear”, threshold values are set based on the ratio of the print range a to the regular print area. In the case of “smear”, a failure determination is made if it is −NG (%) or less. (“YES” in ST3 described later) If it exceeds -NG (%), it will be judged as passing ("No" in ST3) . However, at this time, if -FB (%) or less, although it is a pass judgment, a warning is output as a feedback target. ("YES" in ST5 described later) . In the case of “smear”, if it exceeds + NG (%), a failure is determined, and if it is + NG (%) or less, it is determined to be acceptable. However, at this time, if it exceeds + FB (%), although it is a pass determination, a warning is output as a feeder back target.
[0042]
With regard to “positional deviation”, the pass / fail judgment is made based on the positional deviation amounts Xmm and Ymm from the regular printing position. As for “bridge”, the ratio of the width dimension B in the range where the boundary line of the inspection window W set around each print range a in the image recognition process crosses the cream solder S to the entire window width is “ If it is determined whether or not the “bridge” is acceptable and the ratio of the width dimension B is equal to or greater than the threshold value, it is determined that the bridge is a harmful “bridge” that is likely to cause a solder joint abnormality during reflow.
[0043]
This screen printing apparatus is configured as described above. Next, a screen printing method will be described with reference to FIGS. In the screen printing described below, prior to the start of the automatic operation of the printing operation, a work operation mode for selecting in advance whether or not to perform cleaning and overprinting as feedback operations after print inspection in the automatic operation is set. .
[0044]
FIG. 9 shows an operation flow when both cleaning and overlap printing are selected in the setting of the work operation mode. First, a printing operation is performed on the substrate 9 that has been carried in (ST1). That is, the mask plate 12 provided with the pattern holes 12a is brought into contact with the substrate 9, and the cream solder is supplied onto the mask plate 12 and the squeegee 14 is slid, whereby the cream is applied to the substrate 9 through the pattern holes 12a. Print the solder.
[0045]
Next, a solder inspection is performed on the printed circuit board 9 (ST2). That is, regarding the printed state of the cream solder on the printed circuit board, inspection items including “bleed” and “smear” are inspected, and a determination result based on a predetermined inspection threshold is output for each inspection item (print inspection) Process). Then, the presence / absence of a defect is determined from the determination result (ST3). Here, if there is a defect in any one of the print target parts, the fact is notified and the apparatus operation is single-stopped (ST4).
[0046]
When there is no defect, it is determined whether or not there is a warning, that is, whether or not the inspection quantities exceed the inspection threshold set as a feedback target (ST5). If there is no warning, the printing state is normal. Is determined, and the process proceeds to a printing operation for the next substrate (ST6). If there is a warning in (ST5), whether or not all the warning contents tend to be blurred (ST7), that is, whether or not all the inspection items targeted for warning are detected for "fading". Determine.
[0047]
If the inspection item that is the warning target includes an inspection item such as “smudge” other than “fading”, cleaning is executed (ST8), and the process proceeds to the printing operation for the next substrate. (ST6). That is, here, whether or not the cleaning operation is to be executed is determined based on the inspection result by the print inspection means (cleaning operation execution determination step). Cleaning is performed (cleaning process). By this cleaning, the next substrate is printed after the cream solder S adhering to the mask plate 12 is removed by “bleeding” or the like, and the occurrence of defects due to leaving the state with a warning is prevented.
[0048]
And In (ST3), the warning content of (ST5) (ST7) If all tend to fade, Prior to performing overprinting, the lower surface of the mask plate 12 is cleaned by the cleaning unit. Cleaning is executed (ST9), then overprinting is executed (ST10), and the process proceeds to (ST6). In overprint printing, the print positioning data for the substrate is read, the substrate 9 is aligned again with respect to the mask plate 12, and the squeegee 14 is slid to perform overprint printing of cream solder on the substrate 9. Then, the printing operation of the board is finished.
[0049]
That is, in the above process, it is determined based on the inspection result of the print inspection process whether or not to perform overprint printing for printing the paste again for the purpose of improving the “blur” state on the printed substrate ( Overprint printing execution determination step), the substrate 9 determined to be overprint printing execution is brought into contact with the mask plate 12 again to print cream solder (overprint printing step). As a result, the “blurred” tendency in which the printing amount is slightly small in the previous printing operation is improved, and the printing quality is improved.
[0050]
FIG. 10 shows an operation flow when only overlap printing is selected in the operation mode setting. In this case, the steps (ST1), (ST2), (ST3), (ST5), and (ST7) are executed as in FIG. If all of them do not correspond to the fading tendency in (ST7), the process proceeds to (ST4) as it is without performing cleaning and single-stops. Other steps are the same as those in FIG.
[0051]
FIG. 11 shows an operation flow when only cleaning is selected in the setting of the work operation mode. Also in this case, the steps (ST1), (ST2), (ST3), (ST5), and (ST7) are executed as in FIG. If all of them fall under the fading tendency in (ST7), the process proceeds to (ST4) and single stops. Other steps are the same as those in FIG.
[0052]
Furthermore, FIG. 12 shows an operation flow when neither cleaning nor overlap printing is selected in the setting of the work operation mode. In this case, the steps (ST1), (ST2), (ST3), and (ST5) are executed in the same manner as in FIG. 9, and if there is a warning, the process proceeds to (ST4) and single-stops. Only when there is no warning, the process proceeds to (ST6) and the printing operation to the next substrate is performed. The printing operation flow shown in FIGS. 9 to 12 is selected according to the characteristics of the substrate to be printed and the required print quality level. In order to improve the productivity by reducing the frequency of single stoppage of the apparatus, it is desirable to select both cleaning and overprinting in the setting of the work operation mode.
[0053]
As described above, in the screen printing shown in the present embodiment, the printed state of the cream solder on the printed board is inspected with respect to the inspection items including “smudge” and “smudge”, and the printed board is printed. On the other hand, whether or not to perform overprint printing for printing the cream solder again for the purpose of improving the state of “blur” is determined based on various inspection quantities obtained in the print inspection. Thereby, it is possible to effectively use the inspection quantities determined in the print inspection and improve the usefulness of the print inspection.
[0054]
【The invention's effect】
According to the present invention, regarding the printing state of the paste on the substrate after printing, inspection is performed for inspection items including “bleeding” in which the paste protrudes from the printing range in the print target portion and “blur” in which the print amount in the print target portion is too small. Determine whether or not to perform overprint printing that prints the paste again on the printed circuit board for the purpose of improving the “smear” condition on the printed circuit board. If all the inspection results are acceptable, but all tend to “smear”, the cleaning unit performs a cleaning operation on the lower surface of the mask plate prior to the overprinting. Therefore, it is possible to effectively utilize the inspection quantities obtained in the print inspection and ensure the usefulness of the print inspection.
[Brief description of the drawings]
FIG. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention.
FIG. 2 is a side view of a screen printing apparatus according to an embodiment of the present invention.
FIG. 3 is a plan view of a screen printing apparatus according to an embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a control system of the screen printing apparatus according to the embodiment of the present invention.
FIG. 5 is a diagram showing storage contents of a program storage unit and a data storage unit of the screen printing apparatus according to the embodiment of the present invention.
FIG. 6 is a diagram showing inspection threshold data of the screen printing apparatus according to the embodiment of the present invention.
FIG. 7 is an explanatory diagram of a printing failure state in screen printing according to an embodiment of the present invention.
FIG. 8 is a diagram showing a display screen of the screen printing apparatus according to the embodiment of the present invention.
FIG. 9 is an operation flowchart of the screen printing method according to the embodiment of the present invention.
FIG. 10 is an operation flowchart of the screen printing method according to the embodiment of the present invention.
FIG. 11 is an operation flowchart of the screen printing method according to the embodiment of the present invention.
FIG. 12 is an operation flowchart of the screen printing method according to the embodiment of the present invention.
[Explanation of symbols]
1 Board positioning part
2 Cleaning unit
9 Board
10 Screen printing department
12 Mask plate
13 Squeegee unit
30 Calculation unit
31 Program storage
31c Print inspection program
31d Feedback processing program
32 Data storage unit
32c printing position data
32d inspection threshold data

Claims (4)

A screen printing apparatus for printing a paste on a substrate through the pattern hole by bringing the substrate into contact with a mask plate provided with a pattern hole, supplying paste onto the mask plate, and sliding a squeegee. A substrate positioning mechanism that positions the substrate relative to the mask plate, a positioning control unit that controls the substrate positioning mechanism based on positioning data, and a squeegee moving unit that moves the squeegee on the mask plate; The printing position storage means that stores positioning data for each substrate when positioning and printing one substrate and the paste printing state on the printed substrate, the paste protrudes from the print range at the print target site. ”And“ smear ”that is too small in the print target area A print inspection means for performing a print inspection and outputting a determination result based on a predetermined inspection threshold for the inspection item, and printing the paste again for the purpose of improving the “blurred” state on the printed substrate When overprint printing execution determination means for determining whether or not to perform overprint printing based on the inspection result by the print inspection means, and all the inspection results by the print inspection means are pass determinations, all tend to be “blurred” Includes a cleaning operation execution determination unit that determines that the cleaning unit performs a cleaning operation of the lower surface of the mask plate prior to the execution of the overprinting . Screen printing according to claim 1, further comprising a mode setting means for setting beforehand a working operating mode that combines the execution and non-execution of the execution and non-execution and the cleaning operation of the overprint printing in automatic operation apparatus. A screen printing method for printing a paste on a substrate through the pattern hole by bringing a mask plate provided with a pattern hole into contact with the substrate, supplying paste onto the mask plate, and sliding a squeegee. The print state of the paste on the printed substrate is subjected to a print inspection including, as inspection items, “bleeding” in which the paste protrudes from the print range in the print target portion and “blur” in which the print amount in the print target portion is too small, Whether to perform a print inspection process that outputs a determination result based on a predetermined inspection threshold for the inspection item, and overprint printing that prints the paste again for the purpose of improving the “blur” state on the printed substrate and overprint print execution determination step of determining based on the inspection result of the printing inspection process or, put on the printing inspection step Although the inspection result is acceptable determination if all "blurring" tendency, a step of executing a mask plate lower surface of the cleaning operation by the cleaning unit prior to the execution of the overprint, is determined subject to overprint print execution A screen printing method comprising: an overprinting step of printing the paste by bringing the substrate again into contact with the mask plate. Screen printing method according to claim 3, characterized in that to set the working mode of operation combines the execution and non-execution of the overprint print execution and non-execution and the cleaning operation at the time of automatic operation in advance.

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