JP2018134805A - Screen printing method, screen printing device, and screen printing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printing method, a screen printing device, and a screen printing system capable of efficient mask cleaning without lowering productivity.SOLUTION: A screen printing method which abuts a substrate to a mask plate, supplies paste on the mask plate, and slides a squeegee to perform screen printing of the paste onto the substrate includes: a screen printing step (ST4) for printing the paste onto the substrate; a print number count step (ST5) for counting the number of printed substrates; a first cleaning step (ST10) for performing mask cleaning when a count number has reached a prescribed set number; and a second cleaning step (ST2) for performing the mask cleaning when a prescribed phenomenon not dependent on the count number is generated. When the first cleaning step (ST10) or the second cleaning step (ST2) is performed, the count number is initialized.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a screen printing method, a screen printing apparatus, and a screen printing system for printing paste such as cream solder on a substrate.

  In mounting an electronic component, a paste such as cream solder is applied to the surface of the substrate prior to mounting the electronic component on the substrate. In this paste application, the substrate is brought into contact with a mask plate provided with a pattern hole, the paste is supplied onto the mask plate, and the squeegee is slid to print the paste on the substrate through the pattern hole. Printing devices are widely used. In the screen printing apparatus, the following printing failure may occur in the process of repeatedly executing screen printing. That is, the paste that oozes out of the pattern hole and remains on the lower surface of the mask plate is transferred and oozes out of the print target area, or the paste remains in the pattern hole and is printed on the print target area. “Fuzz” may occur (see, for example, Patent Document 1).

  In the screen printing apparatus described in Patent Document 1, the printing state of the paste printed on the substrate is inspected by a camera provided in the screen printing apparatus, and print defects due to the state of the pattern holes such as “smear” and “blur” are detected. When it is determined that the error has occurred, the machine operator is notified that mask cleaning is necessary. Conventionally, there has been known interval mask cleaning in which when a predetermined number of substrates are printed, mask cleaning is executed to prevent printing defects.

Japanese Patent No. 4910880

  However, in the related art including Patent Document 1, when both mask cleaning that is not dependent on the number of prints that is executed when a printing defect is detected and interval mask cleaning that is executed when the number of prints reaches a predetermined number are executed, The timing at which both are performed is not disclosed, and there is a problem that there is room for further improvement because mask cleaning may be performed excessively and productivity may be reduced.

  Therefore, an object of the present invention is to provide a screen printing method, a screen printing apparatus, and a screen printing system capable of efficiently performing mask cleaning without reducing productivity.

  In the screen printing method of the present invention, the substrate is brought into contact with the mask plate provided with the pattern holes, the paste is supplied onto the mask plate, and the squeegee is slid, whereby the paste is applied to the substrate through the pattern holes. A screen printing method for printing, comprising: a screen printing process for printing a paste on a substrate; a printed sheet counting process for counting the number of printed substrates in the screen printing process; and the count number reaches a predetermined set number A first cleaning step for performing mask cleaning in this case, and a second cleaning step for performing mask cleaning when a predetermined event that does not depend on the number of counts occurs, the first cleaning step, Alternatively, when the second cleaning process is executed, the count number is initialized. Characterized in that it is.

  In the screen printing apparatus of the present invention, the substrate is brought into contact with the mask plate provided with the pattern hole, the paste is supplied onto the mask plate, and the squeegee is slid, whereby the paste is applied to the substrate through the pattern hole. A screen printing apparatus for printing, a printing operation unit for printing paste on a substrate, a printed sheet counting unit for counting the number of substrates printed by the printing operation unit, and a count number reaches a predetermined set number A first cleaning execution processing unit that executes mask cleaning and a second cleaning execution processing unit that executes mask cleaning when a predetermined event that does not depend on the count number occurs. Mask cleaning is performed by the cleaning execution processing unit or the second cleaning execution processing unit. When the number of printed sheets count unit is characterized by initializing the number of the count.

  In the screen printing system of the present invention, an inspection apparatus that inspects the printing state of the paste on the printed substrate, and the inspection result is obtained from the inspection apparatus, the substrate is brought into contact with a mask plate provided with a pattern hole, A screen printing system comprising: a screen printing apparatus that prints a paste on a substrate through the pattern holes by supplying a paste on a mask plate and sliding a squeegee, wherein the screen printing apparatus includes: Item 11. The screen printing apparatus according to any one of Items 6 to 10.

  According to the present invention, it is possible to efficiently perform mask cleaning without reducing productivity.

The block diagram which shows the structure of the component mounting system of one embodiment of this invention The front view which shows the structure of the screen printing apparatus of one embodiment of this invention The top view which shows the structure of the screen printing apparatus of one embodiment of this invention Structure explanatory drawing of the cleaning unit of the screen printing apparatus of one embodiment of this invention (A) (b) (c) Explanatory drawing of the screen printing process by the screen printing apparatus of one embodiment of this invention. The figure which shows an example of the screen display of the test result by the test | inspection apparatus of one embodiment of this invention (A) (b) (c) (d) Explanatory drawing of the mask cleaning process in the screen printing apparatus of one embodiment of this invention. The block diagram which shows the structure of the control system of the screen printing system of one embodiment of this invention (A) (b) Explanatory drawing of the timing of mask cleaning in the screen printing apparatus of one embodiment of the present invention The flowchart which shows the screen printing method in the screen printing system of one embodiment of this invention The flowchart which shows the 1st cleaning process in the screen printing system of one embodiment of this invention. The flowchart which shows the 2nd cleaning process in the screen printing system of one embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The configuration, shape, and the like described below are illustrative examples, and can be appropriately changed according to the specifications of the component mounting system, the screen printing system, the screen printing apparatus, and the inspection apparatus. Below, the same code | symbol is attached | subjected to the element which respond | corresponds in all the drawings, and the overlapping description is abbreviate | omitted. In FIG. 3 and a part to be described later, as a biaxial direction orthogonal to each other in a horizontal plane, an X direction (horizontal direction in FIG. 3) in the substrate transport direction and a Y direction (vertical direction in FIG. 3) orthogonal to the substrate transport direction. Is shown. 2 and a part to be described later, the Z direction (vertical direction in FIG. 2) is shown as the height direction orthogonal to the horizontal plane. The Z direction is the vertical direction or the orthogonal direction when the screen printing apparatus is installed on a horizontal plane.

  First, the component mounting system 1 will be described with reference to FIG. The component mounting system 1 includes a screen printing device M1, an inspection device M2, and component mounting devices M3 and M4 connected to each other, connected to each other via a communication network 2, and controlled by a management computer 3 as a whole. Yes.

  The screen printing apparatus M1 is a paste of cream solder (hereinafter referred to as “paste”) in which a solvent is mixed with granular solder Sa on a land L (electrode) formed on a substrate B through a mask plate provided with a pattern hole. It has a function of transferring by screen printing (referred to as “S”) (see FIG. 5B). The inspection device M2 inspects the printing status of the paste S, for example, measures the paste amount of the transferred paste S by imaging the paste S screen-printed on each land L of the substrate B after screen printing with an inspection camera. It has a function. The component mounting apparatuses M3 and M4 have a function of picking up a component from a component supply unit by a mounting head and transporting and mounting the component to the mounting position of the substrate B on which the paste S is transferred.

  As described above, the component mounting system 1 includes the inspection device M2 and the component mounting devices M3 and M4, and the components are mounted on the substrate B by screen printing the paste S (cream solder). The substrate after mounting the components is sent to the reflow process, and the mounting substrate is manufactured by melting the cream solder and soldering the component terminals of the components mounted on the substrate B to the lands L of the substrate B.

  Next, the structure of the screen printing apparatus M1 will be described with reference to FIGS. The screen printing apparatus M1 is an apparatus that screen-prints the paste S on the substrate B through the mask M that is spread on the frame 5 that circulates the mask plate 4 provided with the pattern holes 4h. The pattern hole 4h is formed in the mask plate 4 corresponding to the shape and position (see FIG. 3) of the land L (electrode) formed in the substrate B. The screen printing apparatus M1 includes a substrate holding and moving unit 6, a squeegee unit 7, a camera unit 8, a cleaning unit 9, and a paste supply device (not shown).

  The substrate holding / moving unit 6 is provided on the base 10 and holds and moves the substrate B. The mask M is held in a horizontal position above the substrate B held by the substrate holding and moving unit 6. The squeegee unit 7 is provided above the mask M. The camera unit 8 is provided below the mask M. The paste supply device is provided integrally with the squeegee unit 7 and supplies the paste S onto the mask plate 4.

  Next, details of each unit included in the screen printing apparatus M1 will be described in order. In FIG. 2, the substrate holding and moving unit 6 includes an XYθ moving mechanism 11, a base table 12, a first elevating table 13, and a second elevating table 14 provided in order on the base 10 from below. The base table 12 is moved in the horizontal plane by the XYθ moving mechanism 11 and rotated θ around the Z axis. The first lifting table 13 is lifted and lowered with respect to the base table 12 by a first lifting table lifting motor 13m. The second lifting table 14 is lifted and lowered with respect to the first lifting table 13 by a second lifting table lifting motor 14m.

  Above the first lifting table 13, a pair of conveyor support members 15 extending through the second lifting table 14 and extending upward are provided. The pair of conveyor support members 15 support a pair of transport conveyors 16 that extend in the X direction and are arranged to face each other in the Y direction. A pair of conveyance conveyors 16 supports both ends of the substrate B from below and conveys them in the X direction. A lower receiving member 17 is provided on the upper surface of the second lifting table 14. Above the pair of transport conveyors 16, a pair of clamp members 18 that extend in the X direction and are arranged to face each other in the Y direction are provided. The pair of clamp members 18 are opened and closed in the Y direction by the operation of the clamp member opening and closing cylinder 18s, and are held (clamped) by sandwiching both end portions of the substrate B supported by the lower receiving member 17.

  In FIG. 2, the squeegee unit 7 includes two squeegees 20 arranged opposite to each other in the Y direction below a squeegee base 19 provided extending in the X direction. The squeegee base 19 is moved in the Y direction by a squeegee unit moving mechanism (not shown). The two squeegees 20 are individually moved up and down with respect to the squeegee base 19 by a squeegee lifting cylinder 21 provided on the squeegee base 19. The squeegee unit 7 lowers one squeegee 20 on the mask plate 4 to which the paste S is supplied and makes it contact with the squeegee in the Y direction (hereinafter referred to as “outward direction”). Perform the action. Similarly, the squeegee unit 7 performs a squeegee operation in the return direction in which the other squeegee 20 is moved in another Y direction opposite to the one Y direction (hereinafter referred to as “return direction”).

  2 and 3, the camera unit 8 includes a mask recognition camera 22 in which the imaging field for imaging the mask plate 4 from below is directed upward, and a substrate recognition camera in which the imaging field for imaging the substrate B from above is directed downward. 23. The camera unit 8 is movably mounted on a head X-axis table 24 that extends in the X direction and includes an X-axis moving mechanism (not shown) that moves the camera unit 8 in the X direction. The X-axis table 24 is movably coupled to a head Y-axis table 25 that extends in the Y direction and includes a Y-axis moving mechanism (not shown) that moves the X-axis table 24 in the Y direction. The camera unit 8 drives the X-axis moving mechanism and the Y-axis moving mechanism to move horizontally between the mask plate 4 and the substrate B in the XY direction so as to recognize the mask plate 4 and the substrate B at the same time.

  Next, the configuration of the cleaning unit 9 will be described with reference to FIGS. The cleaning unit 9 is mounted on the head X-axis table 24 and moves in the Y direction below the mask plate 4 by driving the Y-axis moving mechanism. The cleaning unit 9 is provided with a paper roll 27 A around which unused cleaning paper 26 is wound, a paper roll 27 B around which used cleaning paper 26 is wound, and a wiping head 28. The cleaning paper 26 drawn out from the paper roll 27A is guided by a plurality of guide rollers 29, wraps around the pressing surface on the upper surface of the wiping head 28, and is wound around the paper roll 27B.

  The wiping head 28 is moved up and down freely by the head lifting mechanism 30 (arrow a). The upper surface of the wiping head 28 is a suction surface that abuts against the lower surface of the mask plate 4 and sucks, and a vacuum suction source (not shown) is connected to a suction hole 28a provided in the suction surface. In the cleaning unit 9, suction cleaning is performed by sucking the paste adhering to the mask plate 4 while performing vacuum suction from the suction hole 28 a by operating the vacuum suction source.

  In FIG. 4, the cleaning unit 9 is provided with a cleaning liquid application unit 31 that applies a cleaning liquid containing a solvent that dissolves the paste S attached to the mask plate 4 to the cleaning paper 26 supplied to the wiping head 28. ing. In the cleaning unit 9, wet cleaning is performed in which the cleaning liquid is applied to the cleaning paper 26 by the cleaning liquid application unit 31, and the paste S adhering to the mask plate 4 is wiped while melting. In the wet cleaning, the lower surface of the mask plate 4 may be wiped while being vacuum-sucked from the suction hole 28a as in the suction cleaning.

  Next, a screen printing process in the screen printing apparatus M1 will be described with reference to FIG. In FIG. 5A, lands L (1), L (2), and L (3) are formed on the upper surface of the substrate B. On the upper surface of the substrate B, a resist R that is an insulator is formed in a region other than the land L. On a part of the upper surface of the resist R, circuit symbols, component names, and the like are printed with ink G. The substrate B is aligned below the mask plate 4. Pattern holes 4h (1), 4h (2), 4h (3) are formed in the mask plate 4 corresponding to the lands L (1), L (2), L (3).

  In the screen printing process, first, the substrate B is aligned with the mask plate 4 (alignment process), lifted by the lower receiving member 17 (arrow b), and abutted against the lower surface of the mask plate 4 (substrate abutting process). In FIG. 5B, while the squeegee 20 lowered and brought into contact with the mask plate 4 is slid in the Y direction (arrow c), the paste S supplied on the mask plate 4 is put into the pattern holes 4h. A squeegee operation is performed (squeezing step). In FIG. 5C, the substrate B is then peeled off from the mask plate 4 while lowering the substrate B (arrow d) (plate separation step). As a result, the paste S is transferred (screen printed) onto the land L of the substrate B.

  In FIG. 5A, the paste S adhered in the previous screen printing process remains around the pattern hole 4h (3). Therefore, in FIG. 5C, the paste S (3) transferred to the land L (3) has a “bleed” that is excessive in the amount of paste transferred and spreads from a predetermined range. In FIG. 5C, a part of the paste S (1) filled in the squeezing process is transferred to the land L (1) on the inner wall of the pattern hole 4h (1) of the mask plate 4 after separation of the plate. Remain. For this reason, in the paste S (1) transferred to the land L (1), the “sludge” occurs in which the transferred paste amount is too small and narrower than a predetermined range.

  Next, an example of the inspection result of the printing state of the transferred paste S on the substrate B after screen printing by the inspection apparatus M2 will be described with reference to FIG. FIG. 6 shows the lands L (1) and L (2) of the substrate B after screen printing shown in FIG. 5C, taken by the inspection camera provided in the inspection work unit 63 (see FIG. 8) of the inspection apparatus M2. , L (3), the captured image 32 is shown. In the substrate B, the lands L (1), L (2), and L (3) are covered with a resist R. For convenience, the display of the ink G printed on the resist R is omitted.

  The paste S (2) transferred onto the land L (2) is within a predetermined reference range. However, the paste S (1) transferred onto the land L (1) is less than a predetermined reference range, and “fading” occurs. Further, the paste S (3) transferred onto the land L (3) is larger than a predetermined reference range, and “bleeding” occurs.

  Next, the mask cleaning process in the screen printing apparatus M1 will be described with reference to FIG. In FIG. 7A, the paste S is attached to the mask plate 4 on the inner wall and the periphery of the pattern hole 4h. In the mask cleaning process, first, the wiping head 28 in which the unused cleaning paper 26 is circulated around the pressing surface on the upper surface is moved below the mask plate 4 (head preparation process). At this time, when wet cleaning is performed, the cleaning paper 26 to which the cleaning liquid is applied by the cleaning liquid application unit 31 circulates around the pressing surface of the wiping head 28.

  In FIG. 7B, the wiping head 28 is then raised by the head lifting mechanism 30 (arrow e), and the cleaning paper 26 is brought into contact with the lower surface of the mask plate 4 (head contact process). In FIG. 7C, the paste S adhering to the mask plate 4 is then wiped while the wiping head 28 is moved in the Y direction by the Y axis moving mechanism (arrow f) (paste wiping step). At this time, when performing suction cleaning, the wiping head 28 is moved while suctioning from the suction hole 28a by a vacuum suction source. 7D, the wiping head 28 is then lowered by the head lifting mechanism 30 (arrow g), and the wiping head 28 is retracted to a position where it does not interfere during screen printing (head retracting step).

  As described above, in the screen printing apparatus M1, the substrate holding and moving unit 6, the squeegee unit 7, the camera unit 8, the paste supply device, the X-axis moving mechanism, and the Y-axis moving mechanism are the mask plate 4 provided with the pattern holes 4h. The substrate B is brought into contact with the substrate, the paste S is supplied onto the mask plate 4 and the squeegee 20 is slid to thereby perform screen printing for transferring the paste S to the substrate B through the pattern holes 4h. 53 (see FIG. 8). Further, the cleaning unit 9 and the Y-axis moving mechanism constitute a cleaning operation unit 54 (see FIG. 8) that performs mask cleaning (suction cleaning, wet cleaning) for wiping off the paste S attached to the mask plate 4.

  Next, the configuration of the control system of the component mounting system 1 will be described with reference to FIG. Hereinafter, a configuration related to screen printing (screen printing system) will be described, and a description of a configuration related to component mounting in the component mounting apparatuses M3 and M4 will be omitted. The management computer 3 includes a management control unit 41, a management storage unit 42, an input unit 43, a display unit 44, and a communication unit 45. The input unit 43 is an input device such as a keyboard, a touch panel, or a mouse, and is used when an operation command or data is input. The display unit 44 is a display device such as a liquid crystal panel, and displays various information such as an operation screen for operation by the input unit 43. The communication unit 45 is a communication interface, and exchanges signals and data with the screen printing apparatus M1 and the inspection apparatus M2 via the communication network 2.

  The management control unit 41 is an arithmetic device such as a CPU, and manages the component mounting system 1 (screen printing system) based on information stored in the management storage unit 42. The management storage unit 42 is a storage device and stores component data 42a, board data 42b, mounting position data 42c, and the like. The component data 42 a includes data such as the type and shape of components mounted on the board B in the component mounting system 1. The board data 42b is information related to the board B to be worked on in the component mounting system 1, and includes the size of the board B, the size / position (XY coordinates) of each land L, the target of the paste S transferred to each land L, and The target paste amount is included. The mounting position data 42c includes data such as the type of component mounted on the board B and the XY coordinates of the mounting position.

  In FIG. 8, the screen printing apparatus M1 includes a print control unit 51, a print storage unit 52, a printing work unit 53, a cleaning work unit 54, and a communication unit 55. The communication unit 55 is a communication interface, and exchanges signals and data with the management computer 3 and the inspection apparatus M2 via the communication network 2. The print control unit 51 is an arithmetic device such as a CPU, and refers to various data stored in the print storage unit 52 to control the print work unit 53 to execute screen printing. The print control unit 51 includes, as internal processing functions, a first cleaning execution processing unit 51a, a second cleaning execution processing unit 51b, a printed sheet count unit 51c, a print inspection result acquisition unit 51d, and a stop time measurement unit 51e. .

  The print storage unit 52 is a storage device, and stores board information 52a, count number data 52b, set number data 52c, print inspection result information 52d, and the like. As the board information 52a, information such as the size of the board B necessary for screen printing on the board B to be worked in the screen printing apparatus M1 included in the board data 42b stored in the management storage unit 42 is obtained from the management computer 3. Sent and stored.

  The first cleaning execution processing unit 51a controls the cleaning work unit 54 to perform suction as a first mask cleaning when a first count number N1 described later reaches a first set number (for example, five). Perform cleaning. Further, the first cleaning execution processing unit 51a controls the cleaning work unit 54 to perform the first mask cleaning when the second count number N2 reaches a second set number (for example, 15). Performs wet cleaning as a second mask cleaning of a different type.

  As described above, the first cleaning execution processing unit 51a sets the count numbers (first count number N1, second count number N2) to the predetermined set numbers (first set number, second set number). When it reaches, mask cleaning is executed. The first set number and the second set number are determined in consideration of the required screen printing accuracy and productivity, and are stored in the set number data 52c.

  The second cleaning execution processing unit 51b controls the cleaning operation unit 54 to perform the first operation when a predetermined event described later that does not depend on the count numbers (the first count number N1 and the second count number N2) occurs. The suction cleaning is executed as the mask cleaning 3. Note that the first mask cleaning, the second mask cleaning, and the third mask cleaning are not limited to suction cleaning or wet cleaning. For example, as the second mask cleaning, the suction cleaning may be continuously executed twice.

  The printed sheet count unit 51c counts the number of substrates B on which the printing operation unit 53 has screen-printed after the mask cleaning is executed. Specifically, the printed sheet count unit 51c counts the number of substrates B screen-printed after the first mask cleaning (suction cleaning) is performed as the first count number N1. In addition, the printed sheet count unit 51c counts the number of substrates B screen-printed after the second mask cleaning (wet cleaning) is performed as the second count number N2.

  Then, in the printed sheet count unit 51c, the second cleaning execution processing unit 51b executes the third mask cleaning (suction cleaning) or the first cleaning execution processing unit 51a performs the first mask cleaning (suction cleaning). ) Is executed, the first count number N1 is initialized. In addition, when the first cleaning execution processing unit 51a executes the second mask cleaning (wet cleaning), the printed sheet count unit 51c initializes the first count number N1 and the second count number N2.

  In this manner, the first cleaning execution processing unit 51a executes mask cleaning (hereinafter referred to as “interval mask cleaning”) depending on the number of printed sheets of the screen-printed substrate B. In addition, the second cleaning execution processing unit 51b performs mask cleaning (hereinafter referred to as “non-interval mask cleaning”) independent of the number of screen-printed substrates B to be printed.

  Here, with reference to FIG. 9A, a specific example of the count number of the screen-printed substrate B and interval mask cleaning will be described. In this example, the first set number is 5, the second set number is 15, and a predetermined event that does not depend on the count number with which the second cleaning execution processing unit 51b performs mask cleaning has occurred. To do. Further, it is assumed that the first count number N1 and the second count number N2 are initialized before the screen printing for the substrate B (1) is executed.

  The printed sheet count unit 51c increases the first count number N1 and the second count number N2 by 1 each time screen printing is performed on the substrate B by the printing operation unit 53. When screen printing is performed on the substrate B (5) and the first count number N1 reaches the first set number of five (the second count number N2 is five), the first cleaning execution processing unit 51a executes suction cleaning (first mask cleaning). Then, the printed sheet count unit 51c initializes the first count number N1.

  In FIG. 9A, when screen printing is performed on the substrate B (10) and the first count number N1 reaches the first set number of 5 again (the second count number N2 is 10). Then, suction cleaning (first mask cleaning) is executed, and the first count number N1 is initialized. When screen printing is performed on the substrate B (15) and the second count number N2 reaches the second set number of 15, the first cleaning execution processing unit 51a performs wet cleaning (second mask cleaning). Is executed. At this time, the first count number N1 has also reached the first set number of five, but the first cleaning execution processing unit 51a executes the second mask cleaning with priority. Thereafter, the printed sheet count unit 51c initializes the first count number N1 and the second count number N2.

  In FIG. 8, the inspection apparatus M2 includes an inspection control unit 61, an inspection storage unit 62, an inspection work unit 63, and a communication unit 64. The inspection control unit 61 is an arithmetic unit such as a CPU. The inspection control unit 61 refers to various data stored in the inspection storage unit 62 and controls the inspection working unit 63 to check the printing state of the paste S on the substrate B after screen printing. Causes a print inspection to be performed. The inspection control unit 61 includes a print state determination unit 61a as an internal processing function.

  The inspection storage unit 62 is a storage device, and stores board information 62a, inspection result information 62b, and the like. The board information 62a includes the size and position (XY coordinates) of each land L necessary for executing the print inspection of the board B to be worked in the inspection apparatus M2 included in the board data 42b stored in the management storage unit 42. Information such as the target paste amount of the paste S transferred to each land L is transmitted from the management computer 3 and stored.

  The print state determination unit 61a determines the print state of the paste S transferred to the substrate B based on the position of the paste S acquired as a result of the print inspection and the amount of paste transferred. For example, the printing state determination unit 61a determines that the paste S is in a position irrelevant to the pattern hole 4h provided in the mask plate 4 or the paste amount of the paste S transferred to the land L exceeds a predetermined reference range. If there is a small amount of “blur” or “bleeding” greater than a predetermined reference range, it is determined that the printing is defective. The determination result by the printing state determination unit 61a is associated with the printed board B and land L and stored in the inspection storage unit 62 as inspection result information 62b.

  In FIG. 8, the print inspection result acquisition unit 51d of the screen printing apparatus M1 acquires the inspection result information 62b from the inspection apparatus M2, and stores it as the print inspection result information 52d. That is, the print inspection result acquisition unit 51d acquires the result of inspecting the printing state of the paste S on the substrate B after screen printing. The second cleaning execution processing unit 51b executes suction cleaning (third mask cleaning) when the acquired inspection result is printing failure. That is, the predetermined event that does not depend on the count number in the second cleaning execution processing unit 51b is that the inspection result is a printing failure.

  The stop time measuring unit 51e measures a stop time from when the screen printing is executed until the next screen printing is executed. The second cleaning execution processing unit 51b executes suction cleaning (third mask cleaning) when the stop time measured when the screen printing is executed exceeds a predetermined time. That is, the predetermined event that does not depend on the count number in the second cleaning execution processing unit 51b is that the stop time exceeds the predetermined time. Thereby, for example, when a mounting failure occurs in the component mounting apparatuses M3 and M4 on the downstream side and the screen printing in the screen printing apparatus M1 has been stopped for a long time, the mask printing is performed after the mask plate 4 is cleaned. By restarting, printing defects can be prevented in advance.

  Here, a specific example in which non-interval mask cleaning occurs in addition to interval cleaning will be described with reference to FIG. In this example, the first set number is 5 and the second set number is 15. Further, the event that does not depend on the count number at which the second cleaning execution processing unit 51b executes the non-interval mask cleaning is the occurrence of a printing failure and an excess of the stop time. It is assumed that the first count number N1 and the second count number N2 are initialized before screen printing on the substrate B (21) is executed.

  The printed sheet count unit 51c increases the first count number N1 and the second count number N2 by 1 each time screen printing is performed on the substrate B by the printing operation unit 53. When screen printing is performed on the substrate B (23) and the first count number N1 and the second count number N2 reach three, a printing failure is detected by the inspection apparatus M2. Therefore, the second cleaning execution processing unit 51b executes suction cleaning (third mask cleaning), and the printed sheet count unit 51c initializes the first count number N1. When screen printing is performed on the substrate B (28) and the first count number N1 reaches the first set number of five (the second count number N2 is eight), suction cleaning (first mask) Cleaning) is executed, and the first count number N1 is initialized.

  In FIG. 9B, when screen printing is performed on the substrate B (32) and the first count number N1 reaches 4 sheets and the second count number N2 reaches 12, the stop time of the printing is stopped. An excess has occurred. Therefore, the second cleaning execution processing unit 51b executes suction cleaning (third mask cleaning), and the printed sheet count unit 51c initializes the first count number N1. When screen printing on the substrate B (35) is executed and the second count number N2 reaches the second set number of 15 (the first count number N1 is 3), the first cleaning execution processing unit 51a performs wet cleaning (second mask cleaning). Thereafter, the printed sheet count unit 51c initializes the first count number N1 and the second count number N2.

  Next, a screen printing method by a screen printing system including an inspection apparatus M2 and a screen printing apparatus M1 that acquires an inspection result from the inspection apparatus M2 along the flow of FIGS. 10 to 12 with reference to FIG. 9B. explain. In the screen printing apparatus M1, the stop time is always measured. That is, the screen printing method includes a stop time measuring step of measuring a stop time from when the screen printing is executed until the next screen printing is executed.

  In FIG. 10, the second cleaning execution processing unit 51b determines whether or not the stop time has exceeded a predetermined time before screen printing is executed (ST1: stop time determination step). When the stop time exceeds the predetermined time (Yes in ST1), non-interval mask cleaning is executed (ST2: second cleaning process), and the stop time determination process (ST1) is executed again. When the stop time does not exceed the predetermined time (No in ST1), the substrate B (21) to be printed is loaded into the screen printing apparatus M1 (ST3: substrate loading step). The stop time determination step (ST1) may be performed after the substrate carry-in step (ST3).

  Next, screen printing for printing the paste S on the substrate B is executed (ST4: screen printing step). In FIG. 9B, the stop time does not exceed the predetermined time before the screen printing on the substrate B (21) is executed (No in ST1), and the substrate B (21) is carried in (ST3). Screen printing is then executed (ST4).

  In FIG. 10, the printed sheet count unit 51c then adds 1 to each of the first count number N1 and the second count number N2 to update the count number data 52b (ST5: printed sheet count step). That is, the first count number N1 and the second count number N2 are counted as the number of substrates B that are screen-printed in the screen printing step (ST4). In FIG. 9B, after the screen printing is performed on the substrate B (21), the first count number N1 is updated to 1 and the second count number N2 is updated to 1 (ST5).

  In FIG. 10, the substrate B after screen printing is then transported to the inspection apparatus M2, and a print inspection is performed (ST6: print inspection process). Next, the inspection result obtained by inspecting the printing state of the paste S on the substrate B (21) after screen printing is acquired by the print inspection result acquisition unit 51d (ST7: Print inspection result acquisition step). Next, the second cleaning execution processing unit 51b determines whether or not the acquired inspection result is a printing failure (ST8: printing failure determination step). If the inspection result is printing failure (Yes in ST9), the second cleaning step (ST2) (non-interval mask cleaning) is executed.

  In FIG. 9B, as a result of inspecting the printing state of the paste S screen-printed on the substrate B (23) by the inspection apparatus M2, a printing failure is detected (Yes in ST8). Therefore, the second cleaning step (ST2) (non-interval mask cleaning) is performed before screen printing is performed on the substrate B (24). In addition, after the screen printing on the substrate B (32) is executed and before the screen printing on the substrate B (33) is executed, a printing stop occurs and the stop time exceeds a predetermined time ( Yes in ST1). Therefore, the second cleaning step (ST2) (non-interval mask cleaning) is performed before screen printing is performed on the substrate B (33).

  As described above, when a predetermined event that does not depend on the number of counts occurs, such as printing failure or excess stop time, the second cleaning step (ST2) is executed and mask cleaning (non-interval mask cleaning) is executed. .

  In FIG. 10, when the inspection result is not a printing failure (No in ST8), the first cleaning execution processing unit 51a determines whether the first count number N1 has reached the first set number or the second count value. It is determined whether the count number N2 has reached the second set number (ST9: count number determination step). When either the first count number N1 or the second count number N2 has reached the set number (Yes in ST9), interval mask cleaning is executed (ST10: first cleaning step). That is, when the count numbers (first count number N1, second count number N2) reach predetermined set numbers (first set number, second set number), mask cleaning (interval mask cleaning) is performed. Is executed.

  In FIG. 10, when interval mask cleaning is executed in the first cleaning step (ST10), a stop time determination step (ST1) is then executed. When neither the first count number N1 nor the second count number N2 has reached the set number (No in ST9), the stop time determination step (ST1) is executed without executing the interval mask cleaning.

  In FIG. 9B, since the first count number N1 reaches the first set number (5 sheets) when screen printing is performed on the substrate B (28) (Yes in ST9), the first cleaning is performed. Step (ST10) (interval mask cleaning) is performed. When screen printing is performed on the substrate B (35), the second count number N2 reaches the second set number (15 sheets) (Yes in ST10), so the first cleaning step (ST10) ( (Interval mask cleaning) is executed.

  Next, the details of the first cleaning step (ST10) (interval mask cleaning) will be described along the flow of FIG. First, the first cleaning execution processing part 51a determines whether or not the second count number N2 has reached the second set number (15 sheets) (ST11). When the second count number N2 has reached the second set number (Yes in ST11), the first cleaning execution processing unit 51a performs the second mask cleaning (wet cleaning) (ST12: second). Mask cleaning process). Next, the printed sheet count unit 51c initializes the first count number N1 and the second count number N2, respectively (ST13: second count number initialization step).

  In FIG. 9B, the second count number N2 has reached the second set number (15 sheets) after screen printing on the substrate B (35) (Yes in ST11). Therefore, wet cleaning is performed (ST12), and the first count number N1 and the second count number N2 are initialized (ST13).

  In FIG. 11, when the second count number N2 has not reached the second set number (No in ST11), the first count number N1 has reached the first set number (five). . Therefore, the first cleaning execution processing unit 51a executes the first mask cleaning (suction cleaning) (ST14: first mask cleaning process). Next, the printed sheet count unit 51c initializes the first count number N1 (ST15: first count number initialization step).

  In FIG. 9B, the first count number N1 has reached the first set number (five sheets) after screen printing on the substrate B (28) (No in ST11). Accordingly, suction cleaning is executed (ST14), and the first count number N1 is initialized (ST15).

  Thus, in the first cleaning step (ST10), when the first count number N1 reaches the first set number (five), the first mask cleaning (suction cleaning) is performed (ST14). When the second count number N2 reaches the second set number (15 sheets) larger than the first set number, the second mask cleaning (wet cleaning) different from the first mask cleaning is executed. (ST12).

  When the first mask cleaning (suction cleaning) is executed in the first cleaning step (ST10) (ST14), the first count number N1 is initialized (ST15). When the second mask cleaning (wet cleaning) is performed in the first cleaning step (ST10) (ST12), the first count number N1 and the second count number N2 are initialized (ST13). .

  Next, the details of the second cleaning step (ST2) (non-interval mask cleaning) will be described along the flow of FIG. At this time, it is determined by the second cleaning execution processing unit 51b that an event that does not depend on the count number has occurred. Therefore, the second cleaning execution processing unit 51b executes the third mask cleaning (suction cleaning) (ST21: third mask cleaning process). Next, the printed sheet count unit 51c initializes the first count number N1 (ST22: third count number initialization step).

  In FIG. 9B, it is determined that an event independent of the number of counts has occurred after screen printing on the substrate B (23) and the substrate B (32) (Yes in ST8, Yes in ST1). Cleaning is executed (ST21), and the first count number N1 is initialized (ST22). As described above, when the third mask cleaning is executed in the second cleaning step (ST2) (ST21), the first count number N1 is initialized (ST22).

  As described above, when the first cleaning process (ST10) or the second cleaning process (ST2) is executed, the count numbers (the first count number N1 and the second count number N2) are initialized. Is done. In the example described above, the third mask cleaning (ST21) executed in the second mask cleaning step (ST2) is the first mask cleaning (ST14) executed in the first mask cleaning step (ST10). ) Is the same type of suction cleaning. However, the first mask cleaning and the third mask cleaning are not necessarily the same type.

  First mask cleaning (ST14), second mask cleaning (ST12) executed in the first mask cleaning step (ST10), and third mask cleaning (ST2) executed in the second mask cleaning step (ST2) The type of mask cleaning performed in ST21) can be selected as appropriate.

  As described above, the screen printing apparatus M1 includes the printing operation unit 53, the number-of-printing-counting unit 51c, and the count numbers (the first count number N1 and the second count number N2) of a predetermined set number (first count). The first cleaning execution processing unit 51a that executes the interval mask cleaning when reaching the set number of the second setting number), and the non-interval mask cleaning when the predetermined event that does not depend on the count number occurs And a second cleaning execution processing unit 51b. When the mask cleaning is executed by the first cleaning execution processing unit 51a or the second cleaning execution processing unit 51b, the printed sheet count unit 51c initializes the count number.

  As a result, even when an event that does not depend on the count number such as a printing failure occurs and the non-interval mask cleaning is executed, the interval until the next interval mask cleaning that depends on the count number can be set appropriately. As a result, the mask cleaning can be executed efficiently without reducing the productivity.

  The screen printing system includes a first cleaning execution processing unit 51a, a second cleaning execution processing unit 51b, a printed sheet count unit 51c, a print inspection result acquisition unit 51d, and a stop time measurement unit 51e included in the screen printing apparatus M1. The management computer 3 may be provided. In this case, the management computer 3 determines when the mask cleaning is to be executed, and the mask cleaning is executed in the screen printing apparatus M1 based on the determination result.

  INDUSTRIAL APPLICABILITY The screen printing method, the screen printing apparatus, and the screen printing system of the present invention have an effect that mask cleaning can be performed efficiently without reducing productivity, and are useful in the component mounting field where components are mounted on a substrate. is there.

4 Mask plate 4h Pattern hole 20 Squeegee B Substrate M1 Screen printing device M2 Inspection device N1 First count number N2 Second count number S Paste

Claims (11)

A screen printing method 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 a paste on the mask plate, and sliding a squeegee. ,
A screen printing process for printing the paste on the substrate;
A printing number counting step of counting the number of substrates printed in the screen printing step;
A first cleaning step of performing mask cleaning when the count number reaches a predetermined set number;
A second cleaning step of performing mask cleaning when a predetermined event that does not depend on the count number occurs,
The screen printing method according to claim 1, wherein the count is initialized when the first cleaning step or the second cleaning step is executed. A print inspection result acquisition step for acquiring a result of inspecting the print state of the paste on the printed circuit board further includes:
The screen printing method according to claim 1, wherein the event in the second cleaning step is that the inspection result is a printing failure. It further includes a stop time measuring step for measuring a stop time from when the printing is executed until the next printing is executed,
The screen printing method according to claim 1, wherein the event in the second cleaning step is that the stop time exceeds a predetermined time. In the printed sheet count step, the first count number and the second count number are counted,
In the first cleaning step, when the first count number reaches the first set number, the first mask cleaning is performed, and the second count number is a second value larger than the first set number. When the set number is reached, a second mask cleaning different from the first mask cleaning is performed,
When the mask cleaning is executed in the second cleaning step, or when the first mask cleaning is executed in the first cleaning step, the first count number is initialized,
4. The first count number and the second count number are initialized when the second mask cleaning is executed in the first cleaning step. A screen printing method according to claim 1.   The screen according to claim 4, wherein the mask cleaning performed in the second mask cleaning process is the same type as the first mask cleaning performed in the first mask cleaning process. Printing method. 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 print working unit for printing the paste on the substrate;
A print number counting unit that counts the number of substrates printed by the printing unit;
A first cleaning execution processing section for executing mask cleaning when the count number reaches a predetermined set number;
A second cleaning execution processing unit that executes mask cleaning when a predetermined event that does not depend on the count number occurs,
The screen printing apparatus, wherein when the mask cleaning is executed by the first cleaning execution processing unit or the second cleaning execution processing unit, the printed sheet count unit initializes the count number . A print inspection result acquisition unit that acquires a result of inspecting a printing state of the paste on the printed circuit board,
The screen printing apparatus according to claim 6, wherein the event in the second cleaning execution processing unit is that the inspection result is a printing failure. A stop time measuring unit that measures a stop time from when the printing is executed until the next printing is executed;
The screen printing apparatus according to claim 6, wherein the event in the second cleaning execution processing unit is that the stop time exceeds a predetermined time. The printed sheet count unit counts the first count number and the second count number,
The first cleaning execution processing unit executes the first mask cleaning when the first count number reaches the first set number, and the second count number is larger than the first set number. When the second set number is reached, a second mask cleaning different from the first mask cleaning is performed,
When the second cleaning execution processing unit executes mask cleaning, or when the first cleaning execution processing unit executes the first mask cleaning, the printed sheet count unit initializes the first count number. And
The printed sheet count unit initializes the first count number and the second count number when the first cleaning execution processing unit executes the second mask cleaning. The screen printing apparatus according to any one of 6 to 8.   The mask cleaning performed by the second mask cleaning execution processing unit is the same type as the first mask cleaning performed by the first mask cleaning execution processing unit. Screen printing equipment. An inspection device for inspecting the printing state of the paste on the printed circuit board;
An inspection result is acquired from the inspection apparatus, 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 thereby pass the substrate through the pattern hole. A screen printing system comprising: a screen printing device for printing a paste on the screen;
The screen printing apparatus according to claim 6, wherein the screen printing apparatus is a screen printing apparatus according to claim 6.

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