WO2004098887A1

WO2004098887A1 - Screen printing device mask overlap mounting method, and screen printing device

Info

Publication number: WO2004098887A1
Application number: PCT/JP2004/005852
Authority: WO
Inventors: Yasushi Miyake
Original assignee: Yamaha Motor Co., Ltd.
Priority date: 2003-05-09
Filing date: 2004-04-23
Publication date: 2004-11-18
Also published as: JP2004330690A; JP4515042B2; CN1784307A; CN100522611C

Abstract

A screen printing device comprises a mask (7) having a printing opening, and a substrate support unit (3) holding a substrate (W) which is a printing subject movably with respect to the mask (7). Printing is effected with the overlapping of the substrate (W) and the masks (7) effected by the operation of the substrate support unit (3). Prior to the overlapping of the mask (7) and the substrate (W), a circuit pattern on the substrate (W) and the printing opening in the mask (7) corresponding to this pattern are imaged, and a deviation (positional error) between the circuit pattern and the printing opening is found on the basis of these image data. On the basis of this deviation is effected the overlapping of the mask (7) and the substrate (W) by control-driving the substrate support unit (3).

Description

Description Method for overlaying masks on screen printing equipment, screen printing equipment

TECHNICAL FIELD [0001] The present invention relates to a mask mounting method and a screen printing apparatus for a screen printing apparatus for dispensing paste such as cream solder on a substrate using a screen mask.

Background art

A screen mask (hereinafter, referred to as a mask) is mounted on the substrate set on the stage, and the paste supplied on the mask, such as cream solder, conductive paste, or resistive paste, is expanded with a squeegee to form the mask. 2. Description of the Related Art A screen printing apparatus in which a paste is applied (printed) to a predetermined position on a substrate via an opening is generally known (for example, Japanese Patent Application Laid-Open No. 2001-38875). In this type of screen printing device, the fiducial marks (simply referred to as marks) respectively marked on the mask and the substrate are image-recognized, and based on the recognition result, the mask and the substrate are overlapped while being positioned with respect to each other. ing.

In the above-described conventional apparatus, both the mask and the substrate are positioned based on the image recognition of the mark with reference to the mark respectively marked on the mask and the substrate. This is performed when the mark is correctly marked on the mask and the substrate. Is assumed. In other words, when there is a displacement (position error) in the positional relationship between the mark and the circuit pattern, or when there is a displacement (position error) in the positional relationship between the mark and the printing opening due to deformation such as extension of the mask. However, even if the mask and the substrate are positioned relative to each other on the basis of the mark, and both are mounted, it is difficult to accurately associate the corresponding circuit pattern with the printing opening.

Therefore, it is desired that the mask and the substrate be overlaid in a state where the circuit pattern and the printing opening are accurately associated even when the mark itself on the substrate has a printing deviation or the like. Disclosure of the invention

The present invention has been made in view of the above problems, and has as its object to surely prevent printing misalignment by overlapping a mask and a substrate while positioning them more accurately.

In order to achieve this object, a mask overlaying method for a screen printing apparatus according to the present invention includes: a mask having a printing opening; holding means for holding a substrate which is a printing object; A driving means for relatively moving the means, and the mask and the substrate of a screen printing apparatus for printing by overlapping the substrate held by the holding means and the mask by the operation of the driving means. Prior to the mounting of the mask and the substrate, the circuit pattern of the substrate and the printing opening of the mask corresponding to the circuit pattern are imaged, and these image data are used. A position error of an image between the circuit pattern and the printing opening is obtained based on the error, and the mask and the substrate are overlapped by controlling the driving means based on the error. You.

Further, a screen printing apparatus according to the present invention includes: a mask having a printing opening; holding means for holding a substrate as a printing medium; and driving means for relatively moving the mask and the holding means. In a screen printing apparatus, a first imaging unit capable of imaging a circuit pattern of a substrate held by the holding unit, and an image of a printing opening of the mask corresponding to the circuit pattern imaged by the first imaging unit. A second imaging unit capable of combining the image data of the circuit pattern imaged by the first imaging unit with the image data of the printing opening imaged by the second imaging unit; A composite image generating means for generating image data in a state where parts are superimposed, and a table for displaying an image based on the image data generated by the composite image generating means. Means, image position changing means for changing and displaying a circuit pattern or an image position of a printing opening on a screen in accordance with input information by the input means, and a circuit based on the image data generated by the composite image generating means. A substrate based on a difference between an image position of a pattern or a printing opening and the image position after being changed by the image position changing means; Error calculating means for calculating a position error of the mask; and control means for controlling the driving means based on the error calculated by the error calculating means to overlap the mask and the substrate. is there. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an overall configuration diagram showing a screen printing apparatus according to the present invention.

FIG. 2 is a block diagram showing a control system of the screen printing apparatus.

FIG. 3 is a flowchart showing an example of a printing operation based on control by the control system of FIG.

FIG. 4 is a schematic diagram for explaining a display state of a composite image and a method of calculating a correction value. BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a screen printing machine according to the present invention. The screen printing press includes a printing press main body 2 having a base 1, a substrate support unit 3 for supporting the substrate W in a clamped state, and a conveyor (not shown) for transporting the substrate W to the substrate support unit 3. ).

Although not shown in detail, the substrate support unit 3 includes an R-Z stage 3A that supports the substrate W so as to be able to move up and down (movement in the Z-axis direction) and rotate (rotate around the Z-axis). The X-Y stage 3B supports the Z stage 3A movably in the board transfer direction (X-axis direction; the direction perpendicular to the paper in FIG. 1) and the direction perpendicular to the direction (Y-axis direction). The stage W is configured to move the substrate W by the mutual operation of the stages 3A and 3B. That is, in this embodiment, the holding means and the driving means of the present invention are constituted by the substrate supporting unit 3.

The R-Z stage 3A is equipped with a mask recognition camera 24 (second imaging means) for recognizing a metal mask 7 described below from below, and a lighting device (not shown). The mask recognition camera 24 is provided with an image sensor such as a CCD area sensor, and has a fiducial mark (hereinafter simply referred to as a mark) printed on the lower surface of the metal mask 7. And the printing opening formed in the metal mask 7 can be imaged.

The printing press main body 2 is provided with a U-shaped frame 2b in a plan view having an open front side (the left side in FIG. 1). Supported by a. A metal mask 7 (mask sheet; hereinafter, abbreviated as mask 7) having a printing opening is fixed to the frame 2b, and a squeegee unit 5 is disposed above the mask 7. The mask 7 has its entire periphery held by a frame member 8, and is fixed to the frame 2 b via the frame member 8.

The squeegee unit 5 includes a pair of rail members 5a in the Y-axis direction, which are fixed on the left and right frames 2b on both sides (in FIG. 1, both sides in a direction perpendicular to the paper), and a rail member 5a. A spar member 5b which is mounted in a straddling state and moves along the rail member 5a by the operation of a driving means (not shown), and a solder supply device (not shown) for supplying cream solder on the mask 7 And a pair of squeegees 22, 22 for expanding the cream solder on the mask 7, and lifting means 10 for respectively raising and lowering the squeegees 22, 22, as will be described later. During printing, the squeegees 22 and 22 are reciprocated in the Y-axis direction while the squeegees 22 and 22 are alternately slid along the surface of the mask 7 to expand the solder cream on the mask 7. It is configured to have

Further, on the side of the squeegee unit 5 (right side in FIG. 1) in the printing press body 2, a board recognition camera 2 5 (for recognizing a board W supported on the board support unit 3 from above the board unit 5). A first imaging unit) and its lighting device (not shown) are provided. This substrate recognition device 25 has an image sensor such as a CCD area sensor, and has a fiducial mark (hereinafter simply referred to as a mark) printed on the upper surface of the substrate W, and the substrate W It is configured so that a circuit pattern to be formed can be imaged. The R-Z stage 3A of the substrate support unit 3 has a position corresponding to the operation of the XY stage 3B (ie, a position corresponding to the ski unit 5 (solid line position in FIG. 1; work position)). And a position retracted in the X-axis direction from the position (a dashed line position in FIG. 1; an imaging position). The R-Z stage 3A is disposed at the image position so that the substrate W supported by the stage 3A can be recognized.

FIG. 2 is a block diagram illustrating a control system of the screen printing apparatus. As shown in this figure, the screen printing apparatus has a well-known CPU that executes a logical operation, an R〇M that previously stores various programs for controlling the CPU, and temporarily stores various data during operation of the apparatus. It has a controller 30 composed of a RAM or the like, and each controller 26 to 27 of the squeegee unit 5 and the substrate support unit 3 (R-Z stage 3A, XY stage 3B). The mask recognition camera 24 and the board recognition camera 25 are all connected to the controller 30.

The control device 30 includes a main control unit 31, an image processing unit 32, an error calculation unit 33, an error storage unit 34, and the like as its functional configuration.

The main control means 31 controls the overall operation of the screen printing apparatus. The main control means 31 performs a predetermined printing operation in accordance with a program stored in advance and scans through the controllers 26 to 28. Drive control of one unit 5 and the like. In particular, before the printing process is performed on the first substrate W of the production lot, the substrate supporting unit 3 or the like for executing a preparation process for acquiring data for positioning the substrate W and the mask 7 is required. Drive control.

The image processing means 32 performs a predetermined process on an image taken by the mask recognizing camera 24 and the board recognizing camera 25. During the preparation process, the mask recognizing camera 24 and the board recognizing camera 25 are used. A composite image of the mask 7 (printing opening) and the substrate W (circuit pattern) based on the image data captured by the camera, that is, a virtual image (initial image) in which the mask 7 and the substrate W are superimposed on the mark And an image (updated image data) in which the composite image is changed according to the vector information input by the operation of the input means 36 described later. In particular

Then, based on the vector information, an image in a state where the image of the substrate W is moved with respect to the image of the mask Ί (in a state where the image position is changed) is generated. Note that such image processing

Changing (switching) the image display position in accordance with external input information can be performed based on a conventionally known image processing technique. In the present embodiment, the image processing device 32 is operated according to a program stored in advance. By controlling the main control means 31 Is performed. That is, in this embodiment, the main control means 31 and the image processing device 32 constitute a combined image generating means and an image position changing means of the present invention.

The error calculating means 33 generates an image of the substrate W based on the initial image data generated by the image processing means 32 and the final updated image data obtained by moving the image of the substrate W with respect to the image of the mask 7. Is calculated. '

The error storage means 34 stores the displacement calculated by the error calculation means 33 as a deviation (position error) between the mask 7 and the substrate W, and is calculated by the error calculation means 33 The error is updated and stored.

The control device 30 is further connected to a display means 35 such as a CRT and an input means 36 such as a keypad.

The display means 35 displays information relating to various operating conditions during the printing operation to the operator, etc. During the preparation process, the mask 7 and the substrate W are combined based on the image data generated by the image processing means 32. Display an image.

The input means 36 inputs various information to the control device 30. During the preparation process, the input of vector information for moving the image of the substrate W displayed on the display means 35 is performed by this input. This is done via means 36.

Next, an example of a printing operation based on the control of the control device 30 will be described with reference to a flowchart of FIG.

When the printing operation is started, first, the substrate support unit 3 is set at the initial position where the substrate W can be received, the initial value `` 1 '' is set to the count value, and then the substrate W is transferred from the conveyor. It is carried onto the substrate support unit 3 and clamped (steps S1, S2).

Next, the substrate W is placed at the imaging position by the substrate recognition camera 25 by the operation of the substrate support unit 3 (R-Z stage 3A, XY stage 3B), and the substrate recognition camera 25 places the substrate W on the substrate W. By taking an image of the marked mark, recognition (position recognition) of the substrate W is performed based on the mark (step S3).

Then, it is determined whether or not the counter value is "1", that is, whether or not the substrate W is the first substrate W of the production lot (step S4). Here, if the counter value is "1" When it is determined, the process proceeds to step S5, and thereafter, in steps S5 to S12, a preparation process for acquiring positioning data is executed.

In this preparation process, first, the circuit board of a plurality of regions on the substrate W predetermined based on the mark is imaged by the substrate recognition camera 25 by moving the substrate support unit 3. (Step S5). In the present embodiment, the circuit patterns at two places on the substrate W, which are separated in the diagonal direction, are sequentially imaged by the substrate recognition camera 25.

When the board W is captured by the board recognition camera 25, the board support unit 3 is placed at the working position, and the mark marked on the mask 7 is captured by the mask recognition camera 24, so that the mark is Based on this, recognition of the mask 7 (position recognition) is performed (step S6).

Next, as the substrate support unit 3 moves, two areas including the printing opening corresponding to the circuit pattern imaged in step S5 are sequentially imaged by the mask recognition force camera 24 (step S7). ). At this time, the drive of the substrate support unit 3 (XY stage 3B) is controlled based on the position of the mask 7 recognized in step S6.

Then, from the step, based on the image data of the substrate W and the mask 7 acquired in S7, a virtual image (synthetic image) superimposed on each mark of the mask 7 and the substrate W is formed by the image processing means 3. 2, the virtual image is displayed by the display means 35, and a display requesting the "correction processing" is also performed. For example, in the present embodiment, as shown in FIG. 4 (upper diagram), the composite images of the above two places (images 4OA and 40B) are respectively displayed on the screen of the display means 35. (Steps S8, S9). In the figure, the display to the effect that "correction processing" is requested is omitted.

Here, the “correction process” refers to a process of correcting a shift between the mask 7 and the substrate W on a screen by an operation of an operator. That is, since the composite image displayed on the screen is an image in which the printing opening and the circuit pattern are overlapped with each other on the mask 7 and the mark on the substrate W as described above, the mark on the substrate W and the circuit Both the positional relationship with the pattern and the positional relationship between the mark of the mask 7 and the printing opening are within the appropriate ranges. Then, an image in which the printing opening and the circuit pattern completely correspond (overlap) is displayed as a composite image. However, if there is a deviation in the positional relationship between the mark on the substrate W and the circuit pattern due to, for example, a printing error in the mark, the image 7a of the printing opening is displayed on the composite image as shown in FIG. The circuit pattern image W a is displayed in a state where it is shifted. In the “correction process” described above, such a shift is a process of virtually correcting the shift by operating the input means 36 to move the image of the substrate W. Specifically, the operator inputs vector information, that is, the direction and amount (size) of moving the substrate W, for each of the images 4OA and 40B, and updates the image (the updated image data) according to the input. This is done by matching the image 7a of the opening for printing with the image Wa of the circuit pattern on the screen while confirming (redisplay based on). In this case, the above input operation and image confirmation are repeated as necessary. In step S10, it is determined whether or not the correction processing has been completed. If it is determined that the correction processing has been completed, the error calculating means 33 calculates the error between the substrate W and the mask 7 (step S10). S 11), the calculation result is updated and stored in the error storage means 34 (step S 12). For example, after the correction processing, when the operator operates the input means 36 to input that the correction processing work has been completed, “YES” is determined in the step S10.

In step S 1 1, as shown in FIG. 4 (lower side in FIG.), X- Y-direction variation in the image center in our Keru substrate W to the image _{4 0 a (Ο → 0 1} ') and an image 4 The average value of the change in the X and Y directions at the center of the image of the substrate W in O b (0 ₂ → 0 ₂ ′) is obtained as the error between the substrate W and the mask 7 in the X and Y directions. In each of the images 40a and 40b, a line segment (Oi-Os) connecting the image center of the substrate W before correction and a line segment (Oi'-0) connecting the image center of the substrate W after correction. _The angle 0 with ₂ ′) is obtained as an error between the substrate W and the mask 7 in the R-axis direction.

When the preparation processing of steps S5 to S12 is completed in this way, the substrate support unit 3 is moved to the work position, and the substrate W is positioned with respect to the mask 7 in the X, Y, and R axis directions. The substrate W is lifted by the operation of the stage 3 、, whereby the substrate W is loaded on the mask 7 from below (step S 13). substrate

The positioning of W is performed based on the mark images acquired in steps S3 and S6. After the basic positioning of the substrate W with respect to 7 is performed, the position of the substrate W is corrected based on the error data stored in the error storage means 34. Note that the basic positioning operation and the position correction may be performed simultaneously. After the substrate W is overlaid on the mask 7, the squeegee unit 5 is operated, whereby the printing process is started (step S14). Specifically, after the squeegees 22 and 22 are arranged at a predetermined work start position, the squeegees 22 and 22 (one side squeegee 22) are moved to a predetermined height by the operation of the lifting / lowering means 10. The position, that is, the tip (lower end) is set at the height position where it contacts the mask 7. Then, after the cream solder is supplied onto the mask 7 by the solder supply device, the squeegees 22 and 22 alternately slide along the surface of the mask 7 while reciprocating in the Y-axis direction. The cream solder is applied to the substrate W through the printing opening of the mask 7.

Then, it is determined in step S15 whether or not the printing process has been completed. If it is determined that the printing process has been completed, the squeegees 22 and 22 are reset to the rising end position, and the substrate support is performed. The unit 3 is reset to the initial position, and thereafter, the substrate W is unloaded (step S16).

When the substrate W is unloaded, it is determined whether or not the processing of the predetermined number N of the substrates W has been completed (step S17), and if it is determined that the processing has not been completed, the count value is determined. Is incremented (step S18), the process proceeds to step S2, and the next substrate W is carried into the substrate support unit 3.

If it is determined in step S4 that the counter value is not "1", that is, if the board W is not the first board W in the production lot, the processing in steps S5 to S12 is skipped, and the processing in step S5 is skipped. After the mark recognition processing of 19, the process proceeds to step S13. That is, if NO is determined in step S4, the substrate W is reset to the working position by the operation of the substrate support unit 3, and is marked on the mask 7 by the mask recognition camera 24 mounted on the substrate support unit 3. Mark is imaged

(Step S 19). Then, after the basic positioning of the substrate W with respect to the mask 7 is performed based on the mark images acquired in steps S 3 and S 19, the error data stored in the error storage means 34 is temporarily reduced. Based on this, the position of the substrate W is corrected, and the substrate W is mounted on the mask 7 in this state. In this way, when it is finally determined in step S17 that the processing of the predetermined number N of substrates W has been completed, this flowchart ends.

As described above, in this screen printing apparatus, a specific shift (position error) between the circuit pattern and the printing opening when the substrate W and the mask 7 are positioned relative to each other with reference to the mark is determined in advance (preparation). Processing: Steps S 5 to S 12) in FIG. 3 During the printing processing, the substrate W and the mask 7 are positioned based on the fiducial mark, and the substrate W is determined based on the error obtained in the above-described preparation processing. And the position of the mask 7 are corrected. For example, when there is an error in the positional relationship between the mark and the circuit pattern due to a printing error of the mark, or when the mask itself is deformed by elongation or the like, the mask is deformed. Even if there is an error in the positional relationship between the mask and the printing opening, the substrate W and the mask 7 are overlaid with the corresponding circuit pattern and the printing opening securely matched. be able to . Therefore, compared with the conventional screen printing apparatus that positions the substrate and the mask mutually based only on the image recognition of the mark, the substrate W and the mask 7 can be more accurately overlapped, and as a result, the printing misalignment can be caused. This has the effect of more reliably preventing the occurrence of phenomena.

In particular, in the above-described preparation operation, a virtual image in which the image of the circuit pattern and the image of the printing opening are superimposed on the screen with reference to the mark is displayed on the screen, and the operator operates the input means 36 while watching the screen. By moving the pattern image Wa on the screen, the above error is obtained from the displacement amount and the like, so that a highly reliable value based on the visual judgment of the operator is obtained as the error value. be able to. In other words, even if the printing opening is unevenly displaced due to the deformation of the mask 7, according to the visual judgment of the operator, the balance with the adjacent printing opening is considered. It is possible to match the printing opening with the circuit pattern. Therefore, there is an effect that mutual positional correction when the substrate W is mounted on the mask 7 can be accurately performed according to a specific state of displacement.

Further, in this screen printing apparatus, error data is stored by executing a preparation process prior to the first printing process of a production lot, and for a substrate W belonging to a common production lot, the error data is stored based on the stored error data. Since the position correction between the mask 7 and the substrate W is performed, the printing process can proceed rationally. There is also an effect. In other words, it is conceivable to perform the preparation process for each substrate of a production lot, but in this case, it takes time to perform the printing process per substrate. On the other hand, when an error occurs in the positional relationship between the mark and the printing opening due to the deformation of the mask 7, the above-described error becomes a value common to each substrate W. In general, mark printing errors on the substrate W often occur in units of production lots. In this case, in a common production lot, the above error tends to be a common value for each substrate W. . Therefore, by performing the preparation process only once before the production lot printing process as described above and storing the error in an updated manner, it is possible to prevent the printing deviation of each substrate W, Print processing can be performed on each substrate in the same time as before, and as a result, both quality and productivity can be achieved.

The screen printing apparatus described above is an embodiment of the screen printing apparatus according to the present invention, and its specific configuration can be appropriately changed without departing from the gist of the present invention. For example, the following embodiments can be adopted.

(1) If the basic positional relationship between the substrate W and the mask 7 can be ascertained by another method, the processing in steps S3 and S6 in FIG. 3 can be omitted.

(2) In the embodiment, the circuit pattern of a plurality of regions on the substrate W is imaged by the substrate recognition camera 25, and the plurality of regions of the mask 7 corresponding to the region are imaged by the mask recognition camera 24. Of course, one area may be imaged. In this case, in the process (error calculation process) of step S11 in FIG. 3, an error between the substrate W and the mask 7 is calculated based on the change amounts of a plurality of coordinate positions in the image of the substrate W. What should I do?

(3) In the embodiment, the operator is configured to operate the input means 36 to move the displayed image of the substrate W on the display screen, thereby causing the error calculating means 33 to calculate the position error. However, the error may be calculated directly from the synthesized image data without performing such an operation by the operator.

In the embodiment, the above-described error data is obtained only once in the production lot by executing the preparation processing (the processing of steps S5 to S12 in FIG. 3) before the printing processing of the first substrate W of the production lot. Of course, the preparation process is executed multiple times during the production lot, and the error data is updated one or more times during the production lot. Is also good. Industrial applicability

As described above, the present invention relatively moves a mask having an opening for printing and a holding means holding a substrate as a printing substrate, so that the substrate held by the holding means and the mask can be moved. The present invention relates to a screen printing apparatus to be overlaid, and is particularly useful for accurately overlaying a substrate, which is a printing substrate, and a mask.

Claims

The scope of the claims

1. A mask having an opening for printing, holding means for holding a substrate as a printing object, and driving means for relatively moving the mask and the holding means, wherein the holding means is operated by the driving means. A method of overlaying the mask and the substrate in a screen printing apparatus for printing by overlaying the substrate held by the means and the mask.

Prior to the mounting of the mask and the substrate, the circuit pattern of the substrate and the printing opening of the mask corresponding to the circuit pattern are imaged, and the circuit pattern and the printing are printed based on the image data. A position error of an image with respect to the image forming opening, and controlling the driving means based on the error to load the mask and the substrate.

2. The method for loading a mask on a screen printing apparatus according to claim 1,

In addition to imaging circuit patterns in a plurality of regions on the substrate as the circuit patterns, imaging the regions of the mask including the printing openings corresponding to the circuit patterns in these regions, respectively. A position error with respect to the opening is obtained, a final position error between the substrate and the mask is obtained based on the position error for each region, and the driving unit is controlled based on the final position error.

A method for mounting a mask on a screen printing apparatus, characterized by comprising:

3. The method according to claim 1, wherein a composite image is generated by superimposing a circuit pattern image and a printing opening image corresponding to the pattern on the basis of the image data. And displaying the composite image on a screen, providing information for moving the circuit pattern or the image of the printing opening, and moving the circuit pattern or the image of the printing opening on the display screen. To match the circuit pattern with the printing opening, and calculate the position error between the circuit pattern and the printing opening based on the difference between the image positions before and after the movement.

4. A mask having an opening for printing, holding means for holding a substrate which is a printing object, In a screen printing apparatus including a driving unit that relatively moves the mask and the holding unit,

A first imaging unit capable of imaging a circuit pattern of a substrate held by the holding unit; and a second imaging unit capable of imaging a printing opening of the mask corresponding to the circuit pattern imaged by the first imaging unit. When,

A state in which the image data of the circuit pattern imaged by the first imaging means and the image data of the printing opening imaged by the second imaging means are combined and the circuit pattern and the printing opening are superimposed. Composite image generation means for generating image data of the following; display means for displaying an image based on the image data generated by the composite image generation means;

Input means for inputting information for moving a circuit pattern or an image of a printing opening among images displayed on the display means;

Image position changing means for changing and displaying the image position of the circuit pattern or the printing opening on the screen according to the input information by the input means;

The position error between the substrate and the mask is determined based on the difference between the circuit position based on the image data generated by the synthetic image generating means or the image position of the printing opening and the image position changed by the image position changing means. Error calculating means to be obtained;

Control means for overlapping the mask and the substrate by controlling the driving means based on the error obtained by the error calculating means;

Have

A screen printing apparatus characterized by the above-mentioned.

5. A screen printing apparatus comprising: a mask having a printing opening; holding means for holding a substrate which is a printing object; and driving means for relatively moving the mask and the holding means.

A first imaging unit capable of imaging a circuit pattern of the substrate serving as the holding unit; and a second imaging unit capable of imaging a printing opening of the mask corresponding to the circuit pattern imaged by the first imaging unit. Means,

Image data of a circuit pattern imaged by the first imaging means and a second imaging means Error calculating means for calculating a position error between the circuit pattern and the printing opening based on the image data of the printing opening captured by

Control means for overlapping the mask and the substrate by controlling the driving means based on the error calculated by the error calculating means.

A screen printing apparatus characterized by the above-mentioned.

6. The screen printing device according to claim 4 or 5,

A storage unit for updatingly storing data relating to the error calculated by the error calculation unit; and the control unit controls the driving unit based on the error data stored in the storage unit.

A screen printing apparatus characterized by the above-mentioned.