WO2020188946A1

WO2020188946A1 - Screen printing device and screen printing method

Info

Publication number: WO2020188946A1
Application number: PCT/JP2019/051000
Authority: WO
Inventors: 萬谷　正幸; 満河内
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2019-03-20
Filing date: 2019-12-25
Publication date: 2020-09-24
Also published as: DE112019007039T5; JP6846609B2; CN113474172A; JP7108827B2; JP2021075060A; CN113474172B; JPWO2020188946A1

Abstract

This printing device has a mask, a substrate-holding part, a substrate-positioning mechanism, a printing head, and a cleaning mechanism. After a cleaning performed by the cleaning mechanism, a printing condition at which the printing head prints a paste onto the substrate is changed on the basis of a cleaning scheme that is executed among a plurality of cleaning schemes.

Description

Screen printing device and screen printing method

The present disclosure relates to a screen printing apparatus and a screen printing method for printing a paste on a substrate.

The screen printing device brings the substrate into contact with the lower surface of the mask having a plurality of openings, moves the squeegee on the mask, pushes a paste such as cream solder into the plurality of openings, and transfers the paste to the substrate. When the screen printing apparatus prints on a predetermined number of substrates, it performs cleaning to remove the paste adhering to the mask. It is known that the transfer amount of the paste printed on the substrate is reduced in printing immediately after cleaning (see, for example, Patent Document 1). In the screen printing apparatus described in Patent Document 1, in printing immediately after cleaning, the attack angle of the squeegee is tilted from that in normal printing to increase the transfer amount so that there is no difference in the paste transfer amount from normal printing. There is.

JP-A-2007-237668

The printing apparatus of the present disclosure includes a mask, a substrate holding portion, a substrate positioning mechanism, a printing head, and a cleaning mechanism.

The mask has multiple openings for printing the paste.

The board holding part holds the board.

The board positioning mechanism moves the board holding part to align the board held by the board holding part with the lower surface of the mask.

The print head prints the paste on the mask onto the substrate through multiple openings.

The cleaning mechanism can use multiple cleaning methods for cleaning the underside of the mask.

After cleaning by the cleaning mechanism, the printing conditions for the print head to print the paste on the substrate are changed based on the cleaning method executed among the multiple cleaning methods.

The screen printing method of the present disclosure is
A screen printing method that prints paste on a substrate.
A substrate contacting process in which the substrate is brought into contact with the lower surface of a mask having a plurality of openings.
The printing process of pushing the paste into multiple openings with the print head,
A cleaning process that uses one of several cleaning methods to remove the paste on the mask,
After the cleaning step, the print condition change step of changing the print condition in which the print head prints the paste on the substrate according to the executed cleaning method,
Have.

FIG. 1 is a configuration explanatory view of the screen printing system of the embodiment. FIG. 2 is a plan view showing the structure of the screen printing apparatus of the embodiment. FIG. 3 is a side view showing the structure of the screen printing apparatus of the embodiment. FIG. 4 is a functional explanatory view of a print head included in the screen printing apparatus of the embodiment. FIG. 5 is a functional explanatory view of a cleaning mechanism included in the screen printing apparatus of the embodiment. FIG. 6 is a block diagram showing a configuration of a control system of the screen printing apparatus of the embodiment. FIG. 7 is a diagram showing an example of a print condition correction information input screen in the screen printing apparatus of the embodiment. FIG. 8 is a flow chart of the screen printing method of the embodiment. FIG. 9A is a diagram illustrating a transition of the volume fraction of the printed paste in the screen printing apparatus of the embodiment. FIG. 9B is a diagram illustrating a transition of the volume fraction of the printed paste in the screen printing apparatus of the embodiment.

In the cleaning of screen printing equipment, a wet cleaning method that uses a solvent and a dry cleaning method that does not use a solvent may be executed at predetermined printing intervals. The degree of reduction in the amount of paste transferred in printing immediately after cleaning differs depending on the cleaning method. However, in the prior art such as Patent Document 1, the same printing conditions are applied immediately after cleaning regardless of the cleaning method. Therefore, the transfer amount of the printed paste may vary, and the print quality may vary.

An embodiment of the present disclosure will be described in detail below with reference to the drawings. The configuration, shape, and the like described below are examples for explanation, and can be appropriately changed according to the specifications of the screen printing system and the screen printing device. In the following, the corresponding elements are designated by the same reference numerals in all the drawings, and duplicate description will be omitted. Hereinafter, the transport direction of the substrate (horizontal direction in FIG. 2) is the X direction, and the direction orthogonal to the X direction in the horizontal plane (vertical direction in FIG. 2) is the Y direction, the X direction and the direction orthogonal to the Y direction (in FIG. 3). The vertical direction) is defined as the Z direction.

First, the configuration of the screen printing system 1 will be described with reference to FIG. The screen printing system 1 is configured by connecting the screen printing device M1 and the print inspection device M2 in series from the upstream side (left side of the paper surface) to the downstream side (right side of the paper surface) in the substrate transport direction. The screen printing device M1 and the printing inspection device M2 are connected to the management computer 3 via the communication network 2. The management computer 3 stores production data including a control program used by the screen printing device M1 and the printing inspection device M2, work history of the screen printing device M1 and the printing inspection device M2, inspection result information, and the like. Then, the management computer 3 transmits information between the screen printing device M1 and the print inspection device M2, transmits information to other devices, and the like. The screen printing system 1 is arranged upstream of the mounting board manufacturing line for mounting components on the board, and the board that has been inspected by the printing inspection device M2 is transported to the component mounting device downstream thereof.

The screen printing device M1 prints the paste on the substrate carried in from the upstream side through the mask in which a plurality of openings are formed. The print inspection device M2 includes an inspection camera and a three-dimensional sensor. The print inspection device M2 inspects the state of the paste printed on the upper surface of the substrate conveyed from the screen printing device M1 and the amount of the paste. The inspection result is transmitted to the management computer 3 and also to the screen printing device M1.

First, the structure of the screen printing apparatus M1 will be described with reference to FIGS. 2 and 3. The screen printing device M1 includes a pair of conveyors 5 extending in the X direction on the base 4. The base 4 is provided with a control unit C. The transport conveyor 5 is controlled by the control unit C, transports the substrate 6 received from the upstream side of the screen printing device M1 in the X direction, and carries it out to the downstream side of the screen printing device M1. A substrate holding unit 7 controlled by the control unit C is provided near the center of the conveyor 5 in the X direction. The substrate holding unit 7 receives the substrate 6 transported by the transport conveyor 5 and holds it at a predetermined clamp position.

Above the substrate holding portion 7, a plurality of openings 8a for printing paste on the substrate 6 and a mask 8 in which a pair of mask side marks 8m are formed are installed. The mask 8 has a rectangular flat plate shape that extends in an XY plane, and its outer circumference is supported by a frame member 8w.

In FIG. 3, an XY table 9, a θ table 10, and a board elevating mechanism 11 are provided on the base 4 in this order from the bottom. The XY table 9 moves the θ table 10 in the horizontal plane (X direction, Y direction). The θ table 10 rotates the substrate elevating mechanism 11 by θ degrees around the Z axis. The substrate elevating mechanism 11 supports the substrate holding portion 7 from below and elevates it. The XY table 9, the θ table 10, and the substrate elevating mechanism 11 are controlled by the control unit C.

In FIG. 3, a camera unit 13 incorporating a substrate recognition camera and a mask recognition camera is provided below the mask 8. The camera unit 13 moves in the horizontal plane by the camera moving mechanism 14 (see FIG. 6) controlled by the control unit C (arrow a1). The camera unit 13 moves between the substrate 6 and the mask 8 to take an image of the alignment substrate side mark formed on the substrate 6 and the alignment mask side mark 8m formed on the mask 8. The control unit C recognizes the positions of the mask side mark 8m and the substrate side mark based on the image captured by the camera unit 13.

Next, the control unit C sets the XY table 9 and θ so that the plurality of openings 8a formed in the mask 8 and the electrodes formed on the substrate 6 held by the substrate holding unit 7 match based on the recognition result. The position and orientation of the table 10 and the board elevating mechanism 11 are controlled. Next, the control unit C raises the substrate holding unit 7 to bring the substrate 6 into contact with the mask 8 from below. In this way, the substrate holding portion 7 is provided below the mask 8, and the XY table 9, the θ table 10, and the substrate elevating mechanism 11 move the substrate holding portion 7 and are held by the substrate holding portion 7. A substrate positioning mechanism 12 for aligning 6 with the mask 8 is configured.

In FIGS. 2 and 3, a print head 20 that moves in the Y direction by the print head moving mechanism 15 (see FIG. 6) is provided above the mask 8. The print head 20 includes a movement base 21 that moves in a horizontal plane by a print head movement mechanism 15. Two squeegee holding portions 22 (first squeegee holding portion 221 and second squeegee holding portion 222) are arranged side by side in the Y direction on the moving base 21. The squeegee holding portion 22 holds the squeegees 23 (first squeegee 231 and the second squeegee 232) extending in the X direction at the lower ends, and moves up and down by the elevating mechanism 24 provided on the moving base 21. The squeegee holding unit 22 has a built-in attack angle adjusting unit 25 that adjusts the attack angle θ (see FIG. 4), which is the inclination when the squeegee 23 abuts on the mask 8. The print head moving mechanism 15 and the print head 20 are controlled by the control unit C.

Next, the moving operation by the print head 20 will be described with reference to FIG. The moving operation is executed in a state where the substrate 6 held by the substrate holding unit 7 is aligned with the mask 8. The control unit C controls the attack angle adjusting unit 25 to set the squeegee 23 to a predetermined attack angle θ. Next, the control unit C controls the elevating mechanism 24 to lower one squeegee 23 (first squeegee 231) (arrow b) to bring it into contact with the front side of the region where the plurality of openings 8a are formed.

At this time, the control unit C adjusts the contact force F that brings the squeegee 23 into contact with the upper surface of the mask 8 according to the amount of descent of the squeegee 23. Next, the control unit C controls the print head moving mechanism 15 to move the squeegee 23 to the rear side in the Y direction at a moving speed V. When the squeegee 23 moves over the plurality of openings 8a, the paste Pst supplied to the upper surface of the mask 8 is pushed into the plurality of openings 8a with a predetermined printing pressure (pressure). The printing pressure when the paste Pst is pushed into the plurality of openings 8a can be adjusted by the attack angle θ of the squeegee 23, the contact force F, and the moving speed V.

Specifically, the pressure at the time of pushing can be increased by at least one of reducing the attack angle θ, increasing the contact force F, and increasing the moving speed V. The pressure at the time of pushing can be reduced by at least one of increasing the attack angle θ, reducing the contact force F, and decreasing the moving speed V.

When the squeegee 23 moves to the outside (rear side) of the region where the plurality of openings 8a are formed, the control unit C raises one squeegee 23 (for example, the first squeegee 231). Similar to one squeegee 23, the control unit C lowers the other squeegee 23 (for example, the second squeegee 232) to bring it into contact with the mask 8, moves it forward in the Y direction, and pastes it into the plurality of openings 8a. The movement operation of pushing Pst is executed. In this way, the print head 20 has a squeegee 23 that moves while abutting on the upper surface of the mask 8 to push the paste Pst into the plurality of openings 8a, and by moving on the mask 8, the paste Pst on the mask 8 is moved. Printing is performed on the substrate 6 through the plurality of openings 8a.

In FIG. 3, a cleaning mechanism 30 for cleaning the paste Pst remaining on the back surface of the mask 8 is provided below the mask 8 and on the front side in the Y direction. The cleaning mechanism 30 is moved in the Y direction by the cleaning moving mechanism 16 (see FIG. 6) controlled by the control unit C (arrow a2). The cleaning mechanism 30 includes a wiping head 31 that extends in the X direction and moves up and down in the Z direction (arrow a3).

In the cleaning mechanism 30, paper rolls 33A around which unused cleaning paper 32 is wound and paper rolls 33B for collecting used cleaning paper 32 are mounted before and after the wiping head 31 in the Y direction. .. The cleaning paper 32 drawn from the paper roll 33A goes around the upper surface of the wiping head 31 and is wound around the paper roll 33B rotated by the roll rotation mechanism 34 controlled by the control unit C. The cleaning mechanism 30 is controlled by the control unit C, and includes a cleaning liquid application unit 35 that applies a solvent that dissolves the paste Pst to the cleaning paper 32.

Here, with reference to FIG. 5, the operation of mask cleaning for cleaning the paste Pst remaining on the back surface of the mask 8 will be described. During the mask cleaning operation, the control unit C executes mask cleaning by a wet cleaning method in which a solvent is applied to the cleaning paper 32 by the cleaning liquid application unit 35 in a preset pattern, or a dry cleaning method in which no solvent is used. To do.

In the wet cleaning method using a solvent, the control unit C raises the wiping head 31 that orbits the cleaning paper 32 coated with the solvent by the cleaning liquid application unit 35 on the upper surface and brings it into contact with the back surface of the mask 8 (arrow). c1). Next, the control unit C controls the cleaning moving mechanism 16 to move the cleaning mechanism 30 in the Y direction (arrow c2). In the dry cleaning method that does not use a solvent, the control unit C brings the cleaning paper 32, which is not coated with the solvent, into contact with the back surface of the mask 8 with the wiping head 31 to move the cleaning mechanism 30 in the Y direction.

As a result, the paste Pst remaining on the back surface of the mask 8 and the paste Pst remaining in the plurality of openings 8a are wiped off with the cleaning paper 32. The used cleaning paper 32 from which the paste Pst has been wiped off is wound around the paper roll 33B (see FIG. 3) that is rotated by the roll rotation mechanism 34, and the unused cleaning paper 32 is supplied to the upper surface of the wiping head 31. .. In this way, the cleaning mechanism 30 uses a plurality of cleaning methods (wet cleaning method, dry cleaning method) to remove the paste Pst adhering to the mask 8. The wiping head 31 may be provided with a vacuum suction mechanism, and a suction cleaning method of performing mask cleaning while vacuum suction may also be executed.

Here, the effect of mask cleaning will be described with reference to FIG. 9A. In FIG. 9A, the amount (volume fraction) of the paste Pst which is conveyed after screen printing and transferred to the substrate 6 measured by the printing inspection apparatus M2 is displayed in the order of work for each substrate 6. In the screen printing apparatus M1, when screen printing is repeatedly executed without performing mask cleaning, the amount of paste Pst protruding from the plurality of openings 8a of the mask 8 to the back surface gradually increases, and the paste Pst transferred to the substrate 6 The amount gradually increases. If screen printing is continued as it is, the amount of paste Pst transferred to the substrate 6 exceeds the specified value, so mask cleaning is performed periodically.

When mask cleaning is executed after screen printing, part or all of the paste Pst remaining on the opening 8a of the mask 8 and the back surface is removed. Therefore, the amount of paste Pst transferred to the substrate 6 after mask cleaning is smaller than the amount transferred to the substrate 6 immediately before mask cleaning. In particular, wet cleaning using a solvent has a higher effect of removing a flux component that plays a role of lubricating oil on the surface of the opening 8a than dry cleaning, and this tendency appears strongly. Therefore, in the screen printing immediately after the wet cleaning, the amount of paste Pst remaining in the opening 8a without being transferred to the substrate increases, and as a result, the amount of paste Pst transferred to the substrate 6 decreases.

Therefore, the reduction rate Dw after wet cleaning is larger than the reduction rate Dd after dry cleaning. For example, as shown in FIG. 9A, the volume fraction of the paste Pst transferred by the reduction rate Dd is smaller in the fifth substrate 6 after the dry cleaning than in the fourth substrate 6 immediately before. Further, in the ninth substrate 6 after the wet cleaning, the volume fraction of the paste Pst transferred by the reduction rate Dw is smaller than that of the eighth substrate 6 immediately before. As described above, the reduction rate of the paste Pst printed on the substrate immediately after that differs depending on the cleaning method.

Next, the configuration of the control system of the screen printing apparatus M1 will be described with reference to FIG. The control unit C included in the screen printing device M1 includes a conveyor 5, a substrate holding unit 7, a substrate positioning mechanism 12, a camera unit 13, a camera moving mechanism 14, a printing head moving mechanism 15, a cleaning moving mechanism 16, a touch panel 17, and printing. The head 20 and the cleaning mechanism 30 are connected. The touch panel 17 has a display function for displaying an operation screen of the screen printing device M1 on the liquid crystal panel, and an input function for inputting commands and various information by operating the displayed operation screen.

The control unit C includes a storage unit 40, a printing work processing unit 41, a cleaning processing unit 42, and a correction information setting processing unit 43. The storage unit 40 is a storage device, and includes a print condition storage unit 40a and a correction information storage unit 40b. The print condition storage unit 40a stores the print conditions for the print head 20 to print the paste Pst on the substrate 6, the mask cleaning conditions including the timing for executing the mask cleaning, and the like for each type of the substrate 6.

The printing conditions include the pressure (printing pressure) at which the print head 20 pushes the paste Pst into the plurality of openings 8a, the contact force F that brings the squeegee 23 into contact with the upper surface of the mask 8, the moving speed V of the squeegee 23, and the mask 23. The attack angle θ, which is the inclination when the surface is in contact with 8, is included. Further, the mask cleaning condition stores the timing for executing the mask cleaning, the cleaning method, and the like.

Here, an example of the timing of mask cleaning will be described with reference to FIG. 9A. In this example, mask cleaning is performed after continuous screen printing on four substrates 6. Specifically, mask cleaning is executed after screen printing on the fourth, eighth, twelfth, 16th, and twentieth substrates 6. In mask cleaning, a pattern in which dry cleaning is performed twice and then wet cleaning is performed once is repeated. Specifically, dry cleaning is performed before the first sheet and after the fourth sheet, and wet cleaning is performed after the eighth sheet. Then, after the 12th sheet, the dry cleaning is executed after the 16th sheet, and the wet cleaning is executed after the 20th sheet.

In FIG. 6, the correction information setting processing unit 43 displays a print condition correction information input screen for inputting print condition correction information for correcting the paste Pst that decreases after cleaning on the touch panel 17, and displays the input information on the touch panel 17. It is stored in the correction information storage unit 40b. The management computer 3 may include a correction information setting processing unit 43, and the print condition correction information input in the management computer 3 may be transferred to the correction information storage unit 40b and stored.

Here, an example of the print condition correction information input screen 17a displayed on the touch panel 17 will be described with reference to FIG. 7. On the print condition correction information input screen 17a, "correction after cleaning" column 50, "stepwise correction" column 51, "contact pressure correction" column 52, "movement speed correction" column 53, "attack angle correction" column 54 , The input fields of the "application count" field 55 are set in the "wet cleaning" frame 56 and the "dry cleaning" frame 57, respectively. Further, a "cancel" button 58 and a "register" button 59 are set on the print condition correction information input screen 17a. Further, in the "contact pressure correction" column 52, the "movement speed correction" column 53, the "attack angle correction" column 54, and the "applying number of times" column 55, an increase button "△" and a decrease button "▽" are used to assist input. Is set on the print condition correction information input screen 17a.

In the "correction after cleaning" field 50, it is selected and input whether to correct the printing conditions after mask cleaning (valid) or not (invalid). In the "stepwise correction" field 51, whether or not to perform the correction of the printing conditions stepwise (valid) or not (invalid) is selected and input. When the "gradual correction" column 51 is (valid), the printing condition is gradually corrected by the number of times entered in the "applied number of times" column 55. In the "contact pressure correction" column 52, the correction amount of the contact force F of the squeegee 23 is input as a percentage. In the "movement speed correction" column 53, the correction amount of the movement speed V of the squeegee 23 is input as a percentage. In the "attack angle correction" column 54, the correction amount of the attack angle θ of the squeegee 23 is input as an angle.

In FIG. 7, "effective" is input for both wet cleaning and dry cleaning in the "correction after cleaning" column 50, and the printing conditions are corrected after the mask cleaning. In the wet cleaning, "+ 10%" is input in the "contact pressure correction" column 52, and the correction of the contact force F is executed. Further, in the wet cleaning, since the "stepwise correction" column 51 is "valid" and "2" is entered in the "application count" column 55, the printing conditions are corrected stepwise. That is, the contact force F of the first sheet after wet cleaning is increased by 10%, the contact force F of the second sheet is increased by 5%, and the third and subsequent sheets are not corrected. By increasing the contact force F, the printing pressure is increased, and the decrease in paste Pst after cleaning is corrected.

In the dry cleaning, "-15 °" is input in the "attack angle correction" field 54, and the attack angle θ is corrected. In the dry cleaning, since the "gradual correction" column 51 is "invalid" and the "application count" column 55 is "1", the printing conditions are not corrected stepwise. That is, the attack angle θ is reduced by 15 ° for the first sheet after the dry cleaning (the squeegee 23 is laid down), and the second and subsequent sheets are not corrected. By reducing the attack angle θ and letting the squeegee 23 lie down, the printing pressure is increased, and the decrease in paste Pst after cleaning is corrected.

In FIG. 7, when the "Cancel" button 58 is operated, the information input in each input field of the print condition correction information input screen 17a is cleared. When the "register" button 59 is operated, the information input in each input field of the print condition correction information input screen 17a is stored in the correction information storage unit 40b as the print condition correction information. As described above, the printing conditions changed after cleaning are the pressure at which the print head 20 pushes the paste Pst into the plurality of openings 8a (contact force F), the moving speed V at which the print head 20 moves on the mask 8, and the squeegee 23. It is at least one of the inclinations (attack angle θ) when it comes into contact with the mask 8.

In FIG. 6, the printing work processing unit 41 is a screen printing apparatus M1 including a print head 20 based on the print conditions stored in the print condition storage unit 40a and the print condition correction information stored in the correction information storage unit 40b. Control each part to execute screen printing work. The printing work processing unit 41 corrects the printing conditions by a predetermined number of times (applied times) after mask cleaning based on the printing condition correction information, and causes the screen printing work to be executed.

The cleaning processing unit 42 controls the cleaning mechanism 30 and the cleaning moving mechanism 16 based on the mask cleaning conditions stored in the print condition storage unit 40a to execute mask cleaning at a predetermined timing and in a predetermined method after screen printing. .. In this way, after cleaning by the cleaning mechanism 30, the printing work processing unit 41 changes the printing conditions for the printing head 20 to print the paste Pst on the substrate 6 according to the executed cleaning method, and causes screen printing to be executed.

Next, a screen printing method for printing the paste Pst on the substrate 6 by the screen printing apparatus M1 will be described along the flow of FIG. 8 with reference to FIG. 9B. Hereinafter, the screen printing on the 43rd substrate 6 of FIG. 9B will be described.

In FIG. 8, first, the printing work processing unit 41 conveys the 43rd substrate 6 carried in from the upstream side by the transfer conveyor 5 to the substrate holding unit 7, and holds the substrate 6 conveyed by the substrate holding unit 7. (ST1: Substrate loading process). Next, the printing work processing unit 41 corrects the position based on the image captured by the camera unit 13 and brings the substrate 6 held by the substrate holding unit 7 into contact with the lower surface of the mask 8 in which the plurality of openings 8a are formed. (ST2: Substrate contact process).

Next, the printing work processing unit 41 moves the print head 20 based on the printing conditions stored in the printing condition storage unit 40a to push the paste Pst into the plurality of openings 8a (ST3: printing process). Next, the printing work processing unit 41 lowers the substrate holding unit 7 to separate the substrate 6 from the mask 8 (ST4: substrate separation step). Next, the printing work processing unit 41 causes the substrate holding unit 7 to release the substrate 6, and causes the transfer conveyor 5 to carry out the substrate 6 after screen printing to the downstream side (ST5: substrate unloading step). When the screen printing on the planned number of substrates 6 is completed (Yes in ST6), the printing process is completed.

When the printing process of the planned number of sheets has not been completed (No in ST6), the cleaning processing unit 42 determines whether or not the mask cleaning timing is based on the mask cleaning conditions stored in the printing condition storage unit 40a (No). ST7: Mask cleaning judgment process). In FIG. 9B, it is not the timing of mask cleaning after printing the 43rd substrate 6 (No in ST7). Therefore, returning to the substrate carry-in step (ST1), the 44th substrate 6 is carried in, and the printing step (ST3) is executed under the printing conditions stored in the printing condition storage unit 40a.

In FIG. 9B, after printing the 44th substrate 6, it is the timing of dry cleaning (Yes in ST7). In FIG. 8, when the substrate unloading step (ST5) of the 44th substrate 6 is completed, the cleaning processing unit 42 uses a dry cleaning method to remove the paste Pst adhering to the mask 8 (ST8: cleaning step). ).

Next, the printing work processing unit 41 determines whether or not the executed cleaning method is wet cleaning (ST9: cleaning method determination step). Since the executed cleaning method was the dry cleaning method (No in ST9), the printing work processing unit 41 corrects the printing conditions based on the printing condition correction information after the dry cleaning stored in the correction information storage unit 40b. (ST10: Dry-type post-printing condition correction step).

In FIG. 8, the 45th substrate 6 is then carried in by returning to the substrate carry-in step (ST1), and the printing step (ST3) is executed under the printing conditions corrected in the dry post-printing condition correction step (ST9). In FIG. 9B, the corrected volume fraction Cd is added to correct the reduction rate Dd after the dry cleaning, and the transferred paste Pst has a volume fraction close to the target value.

Similarly, when the substrate unloading step (ST5) of the 48th substrate 6 is completed, the cleaning step (ST8) is executed using the wet cleaning method. Next, in the cleaning method determination step (ST9), it is determined that the wet cleaning method is used (Yes), and the printing work processing unit 41 sets the printing conditions based on the print condition correction information after the wet cleaning stored in the correction information storage unit 40b. Correction (ST11: wet post-printing condition correction step).

Next, the board returns to the substrate loading step (ST1), the 49th substrate 6 is carried in, and the printing step (ST3) is executed under the printing conditions corrected in the wet post-printing condition correction step (ST11). In FIG. 9B, the corrected volume fraction Cw is added to correct the reduction rate Dw after wet cleaning, and the transferred paste Pst has a volume fraction close to the target value.

As described above, in the cleaning step (ST8), the paste Pst adhering to the mask 8 is removed by using any of a plurality of cleaning methods. In the cleaning method determination step (ST9), the dry post-printing condition correction step (ST10), and the wet post-printing condition correction step (ST11), after the cleaning step (ST8), the print head 20 is used as a substrate according to the cleaning method executed. This is a printing condition changing step (ST12) for changing the printing conditions for printing the paste Pst on 6.

In the printing condition changing step (ST12), the pressure (contact force F) that the print head 20 pushes the paste Pst into the plurality of openings 8a in the printing step (ST3) based on the printing condition correction information stored in the correction information storage unit 40b. ), The moving speed V at which the print head 20 moves on the mask 8 in the printing step (ST3), and at least one of the inclinations (attack angle θ) when the squeegee 23 abuts on the mask 8 in the printing step (ST3). Is changed. When the stepwise correction is specified in the print condition correction information, the printing step (ST3) is executed under the print condition that is stepwise corrected by the specified number of times of application. After that, the printing step (ST3) is executed under the printing conditions stored in the printing condition storage unit 40a.

As described above, in the screen printing apparatus M1 of the present embodiment, the mask 8 having a plurality of openings 8a for printing the paste Pst, the substrate holding portion 7, and the substrate holding portion 7 are moved. It has a substrate positioning mechanism 12 for aligning the substrate 6 held by the substrate holding portion 7 with the lower surface of the mask 8. Further, the screen printing apparatus M1 uses a printing head 20 that prints the paste Pst on the mask 8 on the substrate 6 through the plurality of openings 8a, and a plurality of cleaning methods (wet cleaning method, dry cleaning method). It has a cleaning mechanism 30 capable of cleaning the lower surface of the surface.

Then, after cleaning by the cleaning mechanism 30, the screen printing apparatus M1 changes the printing conditions for the printing head 20 to print the paste Pst on the substrate 6 according to the executed cleaning method. As a result, it is possible to reduce the variation in the paste Pst printed on the substrate 6 even if a plurality of cleaning methods are used in combination.

The above has been described with the screen printing apparatus M1 provided with the printing head 20 having the squeegee 23. However, the screen printing apparatus is not limited to this form. For example, it may be a screen printing apparatus provided with a pressure type printing head having a pressure portion for pushing the paste Pst stored in the storage chamber onto the mask 8. In that case, the printing conditions changed after cleaning in order to correct the paste Pst that decreases after cleaning are the force (pressurized pressure) applied by the pressurizing unit to the paste Pst in the storage chamber, or the pressurizing print head masks 8. It is a moving speed V that moves on.

Further, the control unit C of the screen printing device M1 has set printing condition correction information based on the state, area, height, volume ratio, etc. of the paste Pst printed on the substrate 6 inspected by the printing inspection device M2. A printing condition learning unit may be provided for automatically learning and adjusting. In that case, the print condition learning unit adjusts the print conditions so that the paste Pst state becomes a preset target state based on the change in the paste Pst state of the plurality of substrates 6 printed after cleaning. Further, the print condition learning unit 66 sets the paste Pst state to a preset target state based on the paste Pst state (volume fraction) of the plurality of substrates 6 having the same cleaning method executed immediately before. Adjust the print conditions.

According to the present disclosure, it is possible to reduce variations in the paste printed on the substrate even when a plurality of cleaning methods are used in combination.

The screen printing apparatus and screen printing method of the present disclosure have an effect of being able to reduce variations in the paste printed on the substrate even when a plurality of cleaning methods are used in combination, and mount electronic components on the substrate. Useful in the field.

1 Screen printing system 2 Communication network 3 Management computer 4 Base 5 Conveyor conveyor 6 Board 7 Board holding part 8 Mask 8a Opening 8w Frame member 9 XY table 10 θ table 11 Board lifting mechanism 12 Board positioning mechanism 13 Camera unit 14 Camera moving mechanism 15 Print head movement mechanism 16 Cleaning movement mechanism 17 Touch panel 17a Printing condition correction information input screen 20 Print head 21 Movement base 22 Squeegee holder 23 Squeegee 24 Lifting mechanism 25 Attack angle adjustment unit 30 Cleaning mechanism 31 Wiping head 32 Cleaning paper

33A Paper Roll

33B Paper roll 34 Roll rotation mechanism 35 Cleaning liquid application unit 40 Storage unit 40a Printing condition storage unit 40b Correction information storage unit 41 Printing work processing unit 42 Cleaning processing unit 43 Correction information setting processing unit 221 First squeegee holding unit 222 First 2 squeegee holder 231 1st squeegee 232 2nd squeegee M1 Screen printing device Pst paste V Moving speed θ Attack angle (tilt)

Claims

A mask with multiple openings for printing the paste,
The board holding part that holds the board and
A substrate positioning mechanism that moves the substrate holding portion to align the substrate held by the substrate holding portion with the lower surface of the mask.
A printing head that prints the paste on the mask onto the substrate through the plurality of openings.
A cleaning mechanism capable of using a plurality of cleaning methods for cleaning the lower surface of the mask,
With
A screen printing apparatus that changes the printing conditions for the print head to print the paste on the substrate based on the cleaning method executed among the plurality of cleaning methods after cleaning by the cleaning mechanism.
The printing conditions, which are changed after the cleaning, include the pressure at which the print head pushes the paste into the plurality of openings.
The screen printing apparatus according to claim 1.
The print head has a squeegee that moves while abutting against the upper surface of the mask and pushes the paste into the plurality of openings.
The printing conditions changed after the cleaning include an inclination when the squeegee comes into contact with the mask.
The screen printing apparatus according to claim 1.
The print head has a pressurizing portion that pushes the paste in the storage chamber onto the mask.
The printing conditions that are changed after the cleaning include the force that the pressurizing section applies to the paste in the storage chamber.
The screen printing apparatus according to claim 1.
The printing conditions changed after the cleaning include the moving speed at which the print head moves on the mask.
The screen printing apparatus according to any one of claims 1 to 4.
A printing condition learning unit that adjusts printing conditions so that the paste state becomes a preset target state based on the state of the paste printed on the substrate is further provided.
The screen printing apparatus according to claim 1.
The screen printing apparatus according to claim 6, wherein the printing condition learning unit adjusts the printing conditions based on the state of the paste on a plurality of substrates when the cleaning method executed immediately before is the same.
The printing condition learning unit adjusts the printing conditions based on the change in the state of the paste on the plurality of substrates printed after the cleaning.
The screen printing apparatus according to claim 6.
The plurality of cleaning methods include at least one of a wet cleaning method using a solvent and a dry cleaning method using no solvent.
The screen printing apparatus according to any one of claims 1 to 8.
A screen printing method that prints paste on a substrate.
A substrate contacting step of bringing the substrate into contact with the lower surface of a mask having a plurality of openings formed therein.
A printing process in which the paste is pushed into the plurality of openings by a print head,
A cleaning step of removing the paste adhering to the mask using one of a plurality of cleaning methods.
After the cleaning step, a printing condition changing step of changing the printing condition for the print head to print the paste on the substrate according to the executed cleaning method, and a printing condition changing step.
To prepare
Screen printing method.
The printing conditions changed in the printing condition changing step include a pressure at which the printing head pushes the paste into the plurality of openings in the printing step.
The screen printing method according to claim 10.
The print head has a squeegee that moves while abutting against the upper surface of the mask and pushes the paste into the plurality of openings.
The printing conditions changed in the printing condition changing step include an inclination when the squeegee comes into contact with the mask in the printing step.
The screen printing method according to claim 10.
The print head has a pressure portion that pushes the paste in the storage chamber onto the mask.
The printing conditions changed in the printing condition changing step include a force applied by the pressurizing unit to the paste in the storage chamber in the printing step.
The screen printing method according to claim 10.
The printing conditions changed in the printing condition changing step include a moving speed at which the printing head moves on the mask in the printing step.
The screen printing method according to any one of claims 10 to 13.
A printing inspection step for inspecting the state of the paste printed on the substrate, and
A printing condition learning step of adjusting the printing conditions so that the state of the paste inspected in the printing inspection step becomes a preset target state, and
Further prepare
The screen printing method according to claim 10.
The printing condition learning step adjusts the printing conditions based on the state of the paste on a plurality of substrates when the cleaning method executed in the cleaning step is the same.
The screen printing method according to claim 15.
The printing condition learning step adjusts the printing conditions based on the change in the state of the paste on the plurality of substrates printed after the cleaning step.
The screen printing method according to claim 15.
The plurality of cleaning methods include at least one of a wet cleaning method using a solvent and a dry cleaning method using no solvent.
The screen printing method according to any one of claims 10 to 17.