JP2005186328A - Screen printing machine, screen printing inspecting device and screen printing inspecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen printing machine, a screen printing inspecting device and a screen printing inspecting method, in which printing inspections (the direct inspection of printing quality after printing and the inspection of a screen mask as the indirect inspection of the printing quality) can be conducted without lowering the working ratio of a mounting line. <P>SOLUTION: When M groups exist on one board 10, inspections are respectively conducted by a screen printing machine 2 on a group 1 in a first sheet of the board 10a, on a group 2 in a second sheet of the board 10b and on a group M in a M-th sheet of the board 10m. When the inspection of M sheets of the board comes to an end, in a (M+1)-th sheet of the board 10m, by returning at the beginning of inspection, the inspection of the group 1 is conducted. Henceforth, the order of groups, on which inspection is conducted similarly, is changed over in every board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inspection of screen printing, and in particular, a screen printing machine for printing cream solder or the like on an electronic circuit board, and a screen printing inspection apparatus for inspecting an electronic circuit board on which screen solder or the like is used for screen printing or a mask used for screen printing, and The present invention relates to a screen printing inspection method.

When a device such as a package or chip is mounted on an electronic circuit board (hereinafter referred to as a board), if the component is mounted on a printed circuit board with insufficient or excessive solder, misalignment, or bridges, Soldering defects such as bridges, tilts, and misalignments occur. In order to avoid such soldering defects, it is important to inspect the substrate on which the solder is printed by the screen printer and the inspection of the screen mask which is indispensable for printing the solder. For this reason, in recent years, a board mounting line including a screen printing machine on which an inspection process is mounted and a printing inspection apparatus independent of the printing apparatus has been proposed (for example, see Patent Document 1).
Conventionally, locations (inspection points) to be inspected on a substrate are set in advance, and all the inspection points are inspected for one substrate. Even when a large amount of printing is performed using a screen mask having the same pattern, all the inspection points are inspected per substrate.
The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
JP-A-8-118596

  However, in the conventional inspection method, since all inspection points are inspected for one substrate, the inspection takes time. For this reason, the problem that the operation rate of a mounting line will fall has generate | occur | produced.

  For example, in a screen printing machine equipped with a print inspection function, a common table is used as a table for positioning a substrate to a mask and a table used for inspecting a printed substrate, so that the printing process and the inspection process are performed simultaneously. I can't do it. That is, the tact time in the screen printing machine is the sum of the printing time and the inspection time. Therefore, the operation rate of a mounting line incorporating such a printing machine is lower than that of a mounting line incorporating a printing machine not equipped with a printing function and a print inspection apparatus. In addition, when there are many inspection points and the time required for the print inspection is long, the operation rate of the mounting line has been reduced.

  In addition, even when a print inspection apparatus independent of the printing apparatus is adopted for the mounting line, in order to perform inspection without reducing the operation rate of the mounting line, one board is printed in the printing machine. It is necessary to perform a print inspection within the time required for. For this reason, as in the case of the printing machine mounted with the above-described inspection process, when there are many inspection points and the time required for the print inspection is long, it is difficult to inspect all the inspection points with the remaining time, As a result, the operation rate of the mounting line was reduced.

  In addition, when the inspection of the state of the screen mask, which is the main cause of printing failure (foreign matter or solder clogging on the screen mask opening, flux or solder bleeding on the back of the screen mask, etc.), that is, indirect printing quality inspection Must be carried out between the printing process on the board and the printing process on the next board. Even in this case, if there are many inspection points, the time required for the inspection becomes longer. It was difficult to perform an inspection without reducing the rate.

  Accordingly, the present invention has been made to solve the above-described problems, and performs printing inspection (direct printing quality inspection after printing, indirect printing without reducing the operation rate of the mounting line. An object of the present invention is to provide a screen printing machine, a screen printing inspection apparatus, and a screen printing inspection method capable of performing inspection of a screen mask, which is a quality inspection.

  In order to solve the above-described problems, a screen printer according to the present invention is a screen printer that prints a predetermined printing material on a substrate through an opening formed in the screen mask. A storage means for storing a plurality of set inspection points divided into a plurality of groups, or storing a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups; Inspecting means for inspecting the printing state of the board inspection points included in one of the groups, and changing means for changing the group inspected by the inspecting means for every arbitrary number of the substrates, To do.

  The screen printer may further include a substrate camera that images the printed substrate, and the inspection unit may inspect the substrate based on image data of the substrate camera.

  Another form of a screen printer according to the present invention is a screen printer that prints a predetermined printing material on a substrate through an opening formed in the screen mask, and a plurality of inspections set on the screen mask. A storage means for storing the points divided into a plurality of groups or storing a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups, and an arbitrary number of the substrates are printed The inspection means for inspecting the state of the screen mask at the inspection points included in one of the groups and the group to be inspected by the inspection means are changed every time an arbitrary number of the substrates are printed. And a changing unit.

  The screen printing machine may further include a mask camera that images a surface of the screen mask that contacts the substrate, and the inspection unit may inspect the screen mask based on imaging data of the mask camera.

A screen printing inspection apparatus according to the present invention is a screen printing inspection apparatus for inspecting a printed board through an opening formed in a screen mask with a predetermined printing material by a screen printing machine. Storing the plurality of inspection points divided into a plurality of groups or storing a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups; It is characterized by comprising inspection means for inspecting the printing state for the substrate inspection points included in one of the groups, and changing means for changing the group inspected by the inspection means for every arbitrary number of substrates.
The screen printing inspection apparatus may further include a substrate camera that images the printed substrate, and the inspection unit may inspect the substrate based on imaging data of the substrate camera.

  A screen printing inspection method according to the present invention is a screen printing inspection method for inspecting a substrate on which a predetermined printing material is printed through an opening formed in a screen mask by a screen printing machine. A first step of storing a plurality of inspection points divided into a plurality of groups, or storing a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups; A second step of inspecting a printing state for the inspection points included in one of the groups, and a third step of changing the group to be inspected in the second step for every arbitrary number of the substrates; It is characterized by providing.

  According to another aspect of the present invention, there is provided a screen printing inspection method for inspecting the screen mask of a screen printing machine that prints a predetermined printing material on a substrate through an opening formed in the screen mask. In the method, a plurality of inspection points set on the screen mask are divided into a plurality of groups and stored, or a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups are stored. A second step of inspecting the state of the screen mask for the inspection points included in one of the groups each time any number of the substrates are printed, and And a third step of changing the group to be inspected in a step every time an arbitrary number of the substrates are printed. And it features.

According to the present invention, a plurality of inspection points are divided into a plurality of groups, and not all of the plurality of inspection points for each substrate, but a print inspection is performed in order only in a predetermined group among the divided groups. Inspection time for one substrate can be shortened. Thereby, the fall of the operation rate of a mounting line can be prevented.
In addition, since the substrate is inspected while changing the group for each arbitrary number of substrates with respect to one screen mask pattern, it is possible to inspect without degrading the reliability (accuracy) of the judgment of printing quality. Become.
Further, according to the present invention, a plurality of inspection points are divided into a plurality of groups, and each time a substrate is printed, a mask inspection is performed not on all of the plurality of inspection points but only on a predetermined group among the divided groups. As a result, the inspection time per time can be shortened. Thereby, the fall of the operation rate of a mounting line can be prevented.
In addition, since the screen mask is inspected while changing the group each time an arbitrary number of substrates are printed with respect to one screen mask pattern, the reliability (accuracy) of indirect judgment of printing quality is lowered. It is possible to inspect without checking.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of an electronic circuit board mounting line provided with a screen printer according to the present embodiment.
In FIG. 1, a mounting line 1 includes a screen printer 2 for printing cream solder on a substrate, and mounters 3 and 4 for mounting various devices such as chips and packages on the substrate on which the solder is printed by the screen printer 2. And a reflow furnace 5 for heating the substrate on which the device is mounted by the mounters 3 and 4 and a substrate transfer conveyor 6 for sequentially feeding the substrate. Here, the quantity of the mounters 3 and 4 can be set freely as appropriate.
The present embodiment is characterized in the operation of the screen printer 2 in such a mounting line 1, particularly in the print inspection function of the substrate.

Next, the configuration of the screen printer 2 according to the present embodiment will be described with reference to FIGS. FIG. 2 is a perspective view showing a main configuration of the screen printing machine 2 according to the present embodiment, and FIG. 3 is a block diagram showing a hardware configuration of the screen printing machine 2 according to the present embodiment.
The screen printing machine 2 according to the present embodiment includes a table 20 that regulates and moves the substrate 10 to a predetermined position, and a screen mask 30 in which openings are formed corresponding to the solder printing pattern to be printed on the substrate 10. A squeegee device 40 for filling cream solder into the opening of the screen mask 30, a substrate recognition camera 50 that is disposed above the table 20 and images the substrate before printing, and is disposed above the table 20. At least a print inspection camera 60 that images the printed substrate 10 and a control device 70 that controls the operation of the entire screen printing machine 2 are provided.

The table 20 regulates the substrate 10 and moves it to a predetermined position. As shown in FIG. 2, such a table 20 is disposed on a base 21 that forms the lower part of the screen printing machine 2 and is installed on the factory floor so as to be movable in the Y direction by a first Y-axis motor 26. A first base plate 23 disposed above the base 22 so as to be movable in the Z direction while being parallel to the base 22 by the first Z-axis motor 27; and on the first intermediate plate 23, The second intermediate plate 24 is disposed so as to be movable in the X direction by the X-axis motor 28, and the stage 25 is supported on the second intermediate plate 24 so as to be rotatable in the θ direction by the θ-axis motor 29. Is done. A known mechanism for fixing the substrate 10 is provided on the stage 25.
Here, the X direction is the direction along the conveyance of the substrate 10, that is, the horizontal direction in FIG. 2, and the right side is the positive direction and the left side is the negative direction in FIG. Further, the Y direction is a direction facing the transport direction of the substrate 10, that is, a depth direction in FIG. 2, and a back side is a positive direction and a near side is a negative direction in a state where FIG. 2 is viewed from the front. Further, the Z direction is the vertical direction, that is, the vertical direction in FIG. 2, and the upper side is a positive direction and the lower side is a negative direction in a state where FIG. 2 is viewed from the front. The θ direction is a direction that rotates about the Z axis, and when viewed from the top, the clockwise direction is the positive direction.
The combinations of motors arranged in order between the base 22 and the first intermediate plate 23, between the first intermediate plate 23 and the second intermediate plate 24, and on the second intermediate plate 24 and the stage 25 are as described above. Furthermore, not only the combination of the order of the Z-axis motor, the X-axis motor and the θ-axis motor but also the combination of any order such as the order of the X-axis motor, the θ-axis motor and the Z-axis motor is possible.
On the stage 25, a mask recognition camera 80 for imaging the back surface of the screen mask 30 is attached at a predetermined position different from the position where the substrate 10 is mounted. The mask recognition camera 80 is constituted by a known CCD (Charge Coupled Device) camera or the like, images the screen mask 30, and sends the image data to the control device 70.

  As shown in FIG. 2, the screen mask 30 is made of a substantially rectangular thin plate of a metal such as an aluminum alloy, and is attached horizontally above the table 20. In such a screen mask 30, a large number of printing holes 31 each having an opening corresponding to a solder printing pattern to be printed on the substrate 10 are formed. The large printing range is about 380 mm × 330 mm, the size of the printing holes 31 is small, for example, about 0.2 mm × 0.2 mm, and the pitch between the printing holes 31 in the X direction or Y direction is small. Then, it is about 0.1 mm.

  The squeegee device 40 is disposed above the screen printing machine 2, and a bracket member 42 that is supported by a second Y-axis motor 46 so as to be movable in the Y direction with respect to a frame member 41 that is connected and fixed to the base 21. The bracket member 42 includes a first squeegee head 43 and a second squeegee head 44 that are supported by the second Z-axis motor 47 and the third Z-axis motor 48 so as to be movable in the Z direction on both sides in the Y direction. The lower portions of the first squeegee head 43 and the second squeegee head 44 have shapes extending left and right in the X direction, and a flexible polymer or a stainless steel spatula (not shown) is attached to the lower end of the squeegee. It has been. In such a squeegee device 40, the first and second squeegee heads 43 and 44 move along the upper surface of the screen mask 30, so that the cream solder supplied on the screen mask 30 is removed from the printing holes 31 of the screen mask 30. Then, it supplies to each land (electrode part which solders components) on the board | substrate 10, and prints.

The substrate recognition camera 50 is composed of a known CCD camera or the like provided above the stage 25 in a state in which the table 20 is moved in the positive direction in the Y direction and is out of the lower area of the screen mask 30. 10 is imaged, and this imaged data is sent to the control device 70.
The print inspection camera 60 is composed of a known CCD camera or the like provided above the stage 25 in a state in which the table 20 is moved in the positive direction in the Y direction and is out of the lower area of the screen mask 30. The substrate 10 thus picked up is imaged, and this imaged data is sent to the control device 70.

  The control device 70 includes an arithmetic device such as a CPU, a storage device such as a memory and an HDD (Hard Disc Drive), an input device that detects input of information from the outside, such as a keyboard, a mouse, a pointing device, a button, and a touch panel. A computer or controller having an I / F device for sending and receiving information to and from the outside, a display device such as a CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), or FED (Field Emission Display), and the computer or controller And the program installed on the computer. That is, the hardware resources and software cooperate to control the hardware resources by a program, and the motor drive unit 71, storage unit 72, image processing unit 73, I / O processing unit 74, inspection shown in FIG. The determination part 75, the display part 76, and the control part 77 are implement | achieved.

The motor driving unit 71 includes a first Y-axis motor 26, a first Z-axis motor 27, an X-axis motor 28, a θ-axis motor 29, a second Y-axis motor 46, a second Z-axis motor 47, and a third Z-axis motor 48. 2 is connected to each motor, and a control signal is sent to each motor based on an instruction from the control unit 77 to control driving of each motor.
Each of the first Y-axis motor 26, the first Z-axis motor 27, the X-axis motor 28, the θ-axis motor 29, the second Y-axis motor 46, the second Z-axis motor 47, and the third Z-axis motor 48 is incorporated with an encoder. The rotational position is fed back to the control device 70 so that the substrate 10, the first squeegee head 43, and the second squeegee head 44 can be accurately positioned.

  The storage unit 72 stores various programs related to the operation of the screen printing machine 2, recognition data input from the image processing unit 73, inspection data for performing a print inspection, and the like. Here, the inspection data refers to inspection points that are information relating to the position of the solder to be inspected, information related to a group to which the inspection point belongs, and the position and size of the solder for determining whether or not the printed solder is normal. It consists of information and various parameters required for image processing (certification setting, threshold value, allowable range value). This inspection data is set in advance.

  The image processing unit 73 is connected to the substrate recognition camera 50, the print inspection camera 60, and the mask recognition camera 80, and issues an imaging instruction to these cameras based on instructions from the control unit 77. Further, from the imaging data imaged by each camera based on this instruction, a positioning mark provided on the substrate 10, a solder state printed on the substrate 10, a positioning mark provided on the screen mask 30, Recognition data obtained by extracting the state of the screen mask 30 is generated and sent to the control unit 77. Note that the recognition data may be stored in the storage unit 72.

  The I / O processing unit 74 is connected to various actuators 81 such as an air cylinder and a regulator provided in the screen printing machine 2 and various sensors 82, and sends data input from the sensor 82 to the control unit 77. At the same time, a control signal is sent to the actuator 81 based on an instruction from the control unit 77. Based on this control signal, the actuator 81 operates.

  The inspection determination unit 75 functions as an inspection unit and a change unit. In the case of a print inspection, the recognition data generated by the image processing unit 73 based on the imaging data of the print inspection camera 60 according to an instruction from the control unit 77, and a storage unit A print inspection is performed based on the inspection data stored in 72. For example, the inspection determination unit 75 detects the printing position or planar shape of the solder printed at the inspection point from the recognition data, and compares whether or not this solder is printed at a predetermined position and size with the inspection data. Judgment.

  The display unit 76 is connected to a known display device 83 such as a CRT, LCD, or FED, and displays various types of information related to the operation of the screen printing machine 2 based on instructions from the control unit 77.

  The control unit 77 controls each operation of the screen printing machine 2 such as substrate loading, substrate and screen mask positioning, printing, inspection, and substrate unloading based on various programs stored in the storage unit 72.

  Next, with reference to FIGS. 1-4, each operation | movement of the screen printer 2 concerning this Embodiment is demonstrated. FIG. 4 is a flowchart showing the operation of the screen printer 2 according to the present embodiment.

[Loading board]
First, when printing solder on the substrate 10, the screen printing machine 2 drives the first Y-axis motor 26, the first Z-axis motor 27, and the X-axis motor 28 to move the stage 25 to a predetermined position, for example, screen printing. The substrate 10 is carried onto the stage 25 and fixed from a transport conveyor (not shown) provided on the positive direction side in the X direction in FIG. 2 of the machine 2 (step S401).

[Positioning]
When the substrate 10 is fixed on the stage 25, the screen printing machine 2 drives the first Y-axis motor 26 to move the stage 25 in the positive direction in the Y direction, and also drives the X-axis motor 28 as necessary. As a result, the stage 25 is arranged at a predetermined position below the substrate recognition camera 50, for example, at a position where the entire substrate 10 is included in the imaging range of the substrate recognition camera 50. Subsequently, the board 10 is imaged by the board recognition camera 50, the position of the positioning mark provided on the board 10 is recognized from the recognition data based on this imaging data, and a position serving as a reference for fixing the board 10 on the stage 25 A deviation (substrate fixation deviation) from the position where the substrate 10 is actually fixed on the stage 25 is detected (step S402).
When the substrate fixing deviation is detected, the screen printing machine 2 drives the first Y-axis motor 26 to move the stage 25 in the negative direction in the Y direction, and the first Z-axis motor 27 or By driving the X-axis motor 28, the mask recognition camera 80 provided on the stage 25 is moved to a predetermined position below the screen mask 30, for example, the position where the entire screen mask 30 is included in the imaging range of the mask recognition camera 80. To place. Subsequently, the screen mask 30 is imaged by the mask recognition camera 80, the position of the positioning mark provided on the screen mask 30 is recognized from the recognition data based on the imaging data, and the screen mask 30 becomes a reference to be fixed. A deviation (mask fixation deviation) between the position and the position where the screen mask 30 is actually fixed is detected (step S403). The screen printing machine 2 drives the first Y-axis motor 26 by a predetermined amount, and at least one of the X-axis motor 28 and the θ-axis motor 29 as necessary based on the detected substrate fixing deviation and mask fixing deviation. In some cases, the first Y-axis motor 26 is further driven to move the stage 25 to a predetermined position below the screen mask 30 where the circuit pattern of the substrate 10 and the opening of the screen mask 30 coincide with each other. By driving the shaft motor 27 and moving the stage 25 in the positive direction in the Z direction, that is, by raising the stage 25, the substrate 10 and the screen mask 30 are brought into contact with each other (step S404).

[printing]
When the substrate 10 and the screen mask 30 are brought into contact with each other, the screen printing machine 2 supplies cream solder onto the screen mask 30 from a solder supply port (not shown), and moves the squeegee device 40 along the upper surface of the screen mask 30 in a predetermined direction. The cream solder is filled in the printing holes 31 of the screen mask 30 by reciprocating in the Y direction (in this embodiment) (step S405).

Specifically, for example, the screen printing machine 2 drives the second Y-axis motor 46 and the second Z-axis motor 47 to move the first squeegee head 43 to a predetermined position on the screen mask 30, as shown in FIG. A squeegee at the lower end is brought into contact with the vicinity of the end portion on the negative direction side in the Y direction of 30 so that the side of the end portion is parallel to the longitudinal direction of the first squeegee head 43. At this time, the second squeegee head 44 is positioned above.
Subsequently, the screen printing machine 2 supplies cream solder between the position where the first squeegee head 43 abuts on the screen mask 30 and the position where the printing holes 31 are provided. When the cream solder is supplied, the screen printing machine 2 drives the second Y-axis motor 46 to bring the squeegee at the lower end of the first squeegee head 43 into contact with the screen mask 30 in the Y direction of FIG. Move in the positive direction. Thereby, the cream solder supplied onto the screen mask 30 is moved in the positive direction in the Y direction on the screen mask 30 by the first squeegee head 43, thereby filling the printing holes 31. At this time, since the second squeegee head 44 is positioned above, it does not contact the cream solder.

When the first squeegee head 43 passes through all the printing holes 31 provided in the screen mask 30, the second Y-axis motor 46 is stopped and the screen printing machine 2 drives the third Z-axis motor 48 to 2 The squeegee head 44 is lowered, and the edge of the second squeegee head 44 and the side of the second squeegee head 44 are placed at a predetermined position on the screen mask 30 near the end of the screen mask 30 shown in FIG. The longitudinal direction is made parallel and the squeegee at the lower end is brought into contact. At this time, the screen printing machine 2 drives the second Z-axis motor 47 to move the first squeegee head 43 to the upper position.
Subsequently, the screen printing machine 2 drives the second Y-axis motor 46 to move in the negative direction in the Y direction of FIG. 2 with the squeegee at the lower end of the second squeegee head 44 in contact with the screen mask 30. Let Thus, the cream solder moved by the first squeegee head 43 is filled in the printing holes 31 by being moved in the negative direction in the Y direction on the screen mask 30 by the second squeegee head 44. At this time, since the first squeegee head 43 is positioned above, it does not contact the cream solder.

  After the cream solder is filled and pressed in the printing holes 31 of the screen mask 30 and printed in this way, the screen printing machine 2 drives the first Z-axis motor 27 to lower the stage 25 in the negative direction in the Z direction. Then, the substrate 10 and the screen mask 30 are separated from each other (step S406), and printing is completed.

[Inspection]
When printing is completed, the screen printing machine 2 drives the first Y-axis motor 26 to move the stage 25 in the positive direction in the Y direction, and if necessary, the first Z-axis motor 27, the X-axis motor 28, and By driving at least one of the θ-axis motors 29, the stage 25 is moved to a predetermined position below the print inspection camera 60, for example, a position where the entire substrate 10 is included in the imaging range of the print inspection camera 60. An inspection is performed (step S407). This print inspection will be described below.
Note that the substrate recognition camera 50 and the print inspection camera 60 may be combined with a camera having the same resolution.

First, the screen printing machine 2 specifies a group of inspection points for inspecting solder previously printed on the substrate 10.
As shown in FIG. 5, solder is printed on the substrate 10 on lands 12 that are connected to the lead portions and exposed electrode portions of the N devices mounted on the substrate 10. In the conventional inspection method, the solder printed on all the lands 12, that is, all the inspection points are inspected for each substrate. In contrast, in the present embodiment, for example, as shown in FIG. 6, N devices are divided into arbitrary M groups. The inspection determination unit 75 of the screen printing machine 2 identifies one group to be inspected next from the groups thus divided, and inspects only the inspection points included in this group.

  Such information regarding group division is set in advance by the user for each screen mask as inspection data, and is stored in the storage unit 72. The number of group divisions and the number of inspection points included in one group can be set as appropriate in consideration of the number of inspection points in one inspection and the time required for the inspection. In addition, the group includes not only a device unit for grouping a plurality of adjacent devices as a unit or grouping for each device type (for example, by size), but also a plurality of adjacent lands 12. It is also possible to divide into groups by one unit, or to divide by individual land 12 units such as the shape and size of the land 12.

Further, in one inspection, only one group of M groups is extracted and specified, and when a print inspection for inspecting only inspection points included in this group is completed a predetermined number of times, another group is extracted and specified. The inspection is performed in the same manner. The order of this extraction is, for example, the order of each group of m1, m2, m3, m1, m4, etc., the order of each group of m1, m2, m3, m4, etc., or m1, m2, m3. , M4, m5, m6, m1, m2, m7, m8..., And the extraction is switched in a desired group order. If possible, all of the M groups are extracted at least once with a predetermined number of extractions. In addition, the number of inspections serving as a trigger for switching the extraction of the group is changed and set based on the group to be inspected before switching.
Furthermore, all the plurality of inspection points and a program related to group division are stored in the storage unit 72, and are programmed before inspection for each substrate type to be printed, for each printing lot on the same substrate, or for every predetermined number of substrates. Divide a plurality of inspection points into groups, and based on the result of the group division, extract and identify one group to be inspected next from the divided groups, and only the inspection points included in this group An inspection may be performed.

When the group to be inspected is specified, the screen printer 2 images the substrate 10 on which the cream solder is printed by the print inspection camera 60, as shown in FIG. For example, as illustrated in FIG. 8, the imaging data includes visual fields 11 a to 11 f assigned to a plurality of devices mounted on the substrate 10, and recognition data obtained by extracting each device and land is an image processing unit. 73. The inspection determination unit 75 extracts the solder state (two-dimensional shape) printed on the inspection points included in the group specified from the recognition data. Further, information relating to the shape of the solder serving as a reference for the inspection points of the specified group is extracted from the inspection data stored in advance in the storage unit 72. For each inspection point, the inspection determination unit 75 compares (for example, area comparison) or pattern matching between the solder shape extracted from the recognition data and information on the solder shape serving as a reference extracted from the inspection data, and prints. It is determined whether or not the process has been performed normally.
It should be noted that a threshold value and an allowable value for deviation from the printed solder position and size reference value for determining whether or not printing has been normally performed can be freely set as appropriate, and in advance as inspection data. Stored in the storage unit 72.

When the determination is made, the inspection determination unit 75 specifies the group of the substrates 10 to be inspected next.
Here, the group that performs the print inspection is switched one by one for each printed substrate 10. For example, as illustrated in FIG. 9, when there are M groups on one substrate 10, the inspection determination unit 75 determines that the first substrate 10 a is for group 1 and the second substrate 10 b is for group 2. The M-th substrate 10m is inspected for the group M, respectively. When the inspection of the M substrates is completed, the (M + 1) th substrate 10n is returned to the beginning and the inspection of the group 1 is performed. Thereafter, the groups to be inspected in the same manner are switched in order of the set groups for each substrate.

[Unloading board]
When no printing failure is found by the above-described print inspection, that is, when printing is performed normally (step S408: NO), the screen printing machine 2 includes the first Y-axis motor 26 and, if necessary, the first Z-axis motor 27, X The shaft motor 28 and the θ-axis motor 29 are driven to move the stage 25 to a predetermined position and, for example, are carried out to the mounter 3 provided on the negative direction side in the X direction in FIG. The unloaded substrate 10 is subjected to processes following the mounters 3 and 4 and the reflow furnace 5, that is, mounting and firing of devices.
On the other hand, when a printing failure is found by the print inspection (step S408: YES), the screen printing machine 2 carries out the substrate 10 in which the printing failure is found to the outside of the screen printing machine 2 (step S410). An instruction to request removal is displayed on the display device 83 (step S411). Here, the screen printer 2 may be provided with a container that collects only the substrates on which printing defects are found. In this case, when a printing failure is found, the screen printing machine 2 automatically carries the substrate on which the printing failure is found to the container. As a result, it is possible to save the trouble of an operator who removes a substrate in which a printing defect is found, which is very convenient.

  As described above, according to the present embodiment, a plurality of inspection points are divided into a plurality of groups, and not all of the plurality of inspection points for each substrate, but a print inspection only with a predetermined group among the divided groups. Thus, the inspection time for one substrate can be shortened. For this reason, the fall of the operation rate of a mounting line can be prevented. In addition, since the print inspection is performed for each group, it is possible to prevent a reduction in the operation rate of the mounting line and increase inspection points. Furthermore, since it is possible to inspect the substrate while changing the group for each arbitrary number of substrates for one screen mask pattern, it is possible to inspect without degrading the reliability (accuracy) of the judgment of printing quality. Become.

  Note that, according to the present embodiment, the groups to be inspected are switched in order, so in the example shown in FIG. 9, the (M−1) printed defective substrates are missed and the substrate is transferred to the subsequent process. May be carried out. However, if the cause of the printing failure is a sudden abnormality of the screen printing machine 2 or the screen mask, such as foreign matter or solder clogging in the screen mask opening, flux or solder bleeding on the back of the screen mask, the failure will continue. Since it continues to occur, it is possible to notify the operator of the occurrence of a defect before producing (M-1) or more printed defective substrates.

  The above-described inspection method is a print inspection method that is effective in a screen printer equipped with a print inspection function, but can also be applied to a dedicated print inspection machine that is independent of the printing process. This is particularly effective when there are many print inspection points and the time required for print inspection is long.

The above-described printing inspection method can also be applied to the inspection of the screen mask 30 (mask inspection) which is an indirect inspection of printing quality. The operation when performing mask inspection will be described with reference to FIG. FIG. 10 is a flowchart showing the mask inspection operation of the screen printer according to this embodiment.
In FIG. 10, steps S1001 to S1006 showing the steps of carrying in, positioning, printing, and carrying out the substrate are the same as the print inspection described with reference to FIG.

[Inspection]
When the substrate 10 on which the solder is printed is carried out to the next process (step S1007), the screen printing machine 2 performs a mask inspection (step S1008).

First, the screen printing machine 2 specifies a group of inspection points for inspecting the screen mask 30 in advance.
As in the case of the substrate 10, predetermined inspection points are divided and set for each group in the screen mask 30, and the inspection determination unit 75 of the screen printing machine 2 selects the next group Q from the divided groups Q. One group to be inspected is identified, and only the inspection points included in this group are inspected.

  Information regarding such group division is set in advance by the user for each screen mask as inspection data and stored in the storage unit 72 as in the case of substrate inspection. The number of group divisions and the number of inspection points included in one group can be set as appropriate in consideration of the number of inspection points in one inspection and the time required for the inspection. In addition, the group includes not only a device unit for grouping a plurality of adjacent devices as a unit or grouping for each device type (for example, by size), but also a plurality of adjacent lands 12. It is also possible to divide into groups by one unit, or to divide by individual land 12 units such as the shape and size of the land 12.

Further, in one inspection, only one group out of Q groups is extracted and specified, and when a screen mask inspection for inspecting only inspection points included in this group is completed a predetermined number of times, another group is extracted and specified. , Do the same inspection. The extraction order is, for example, the order of each group of q1, q2, q1, q3, q1, q4..., The order of each group of q1, q2, q3, q4. , Q3, q4, q5, q6, q1, q2, q7, q8..., And the extraction is switched in a desired group order. If possible, all Q groups are extracted at least once with a predetermined number of extractions. In addition, the number of inspections serving as a trigger for switching the extraction of the group is changed and set based on the group to be inspected before switching.
Furthermore, all of the plurality of inspection points and the program related to group division are stored in the storage unit 72, and before each inspection, for each screen mask type used for printing, for each printing lot in the same screen mask, or for every predetermined number of printing times. The program divides a plurality of inspection points into groups by the program, and based on the division result of this group, one group to be inspected is extracted and specified from the divided groups, and the inspection points included in this group are identified. You may make it test | inspect only about.

  When the group to be inspected is specified, the screen printing machine 2 drives the at least one of the first Y-axis motor 26, the first Z-axis motor 27, the X-axis motor 28, and the θ-axis motor 29 on the stage 25. The provided mask recognition camera 80 is moved to a predetermined position below the screen mask 30, for example, to a position where the entire screen mask 30 is included in the imaging range of the mask recognition camera 80, and the screen mask 30 is imaged by the mask recognition camera 80. To do. Based on this imaging data, the image processing unit 73 creates recognition data similar to the case of the substrate 10 described with reference to FIG. 8, for example. The inspection determination unit 75 extracts the state of the screen mask 30 of the inspection points included in the group specified from the recognition data, particularly the shape of the opening, that is, the position and size of the opening. Further, information relating to the shape of the screen mask 30 serving as a reference for the inspection points of the specified group is extracted from the inspection data stored in the storage unit 72 in advance. The inspection determination unit 75 compares the shape of the screen mask 30 extracted from the recognition data with information about the shape of the reference screen mask 30 extracted from the inspection data for each inspection point (for example, comparison of areas) or a pattern. Matching is performed to determine whether or not the state of the screen mask 30 is normal. This determination is made when, for example, foreign matter or solder clogging in the opening of the screen mask 30, flux on the back of the screen mask 30, solder bleeding, or the like is detected, the inspection determination unit 75 determines that the state of the screen mask 30 is abnormal. Judge that there is.

When the determination is made, the inspection determination unit 75 specifies a group to be inspected next.
Here, the group performing mask inspection is switched one by one each time the substrate 10 is printed. For example, as shown in FIG. 9, when there are M groups in the screen mask 30, the inspection determination unit 75 performs the first printing for the group 1, the second printing for the group 2, and the Mth printing. Each group M is inspected. When the M-th inspection is completed, when the (M + 1) -th printing is performed, the process returns to the beginning and the group 1 inspection is performed. Thereafter, the group to be inspected in the same manner is switched in turn every time the substrate is printed.

[Mask cleaning]
If an abnormality of the screen mask 30 is found by the mask inspection described above (step S1009: YES), the screen printing machine 2 displays an instruction to clean the screen mask 30 on the display device 83 (step S1010). Here, the screen printer 2 may be provided with a mechanism for automatically cleaning the screen mask 30. In this case, the screen printer 2 may automatically clean the screen mask 30 when a mask abnormality is found. As a result, the operator's trouble of cleaning the screen mask 30 can be saved, which is very convenient.
If no abnormality of the screen mask 30 is found by the mask inspection (step S1009: YES), the screen printing machine 2 returns to step S1001 and prints the next substrate 10.

Thus, according to the present embodiment, a plurality of inspection points are divided into a plurality of groups, and every time a substrate is printed, not all of the plurality of inspection points, but only a predetermined group among the divided groups. Since the mask inspection is performed in this manner, the inspection time for one inspection can be shortened. For this reason, the fall of the operation rate of a mounting line can be prevented. Further, since mask inspection is performed for each group, it is possible to prevent a reduction in the operating rate of the mounting line and increase inspection points. Furthermore, since the screen mask is inspected while changing the group each time an arbitrary number of substrates are printed with respect to one screen mask pattern, the reliability (accuracy) of indirect judgment of printing quality is lowered. It is possible to inspect without checking.
In the present embodiment, both the screen mask inspection and the substrate inspection are performed, but one of the inspections is performed, and the inspection based on the grouping is performed sequentially by switching the groups as described above. Also good.

It is a schematic diagram which shows the structure of the mounting line of the electronic circuit board provided with the screen printer concerning this Embodiment. It is a perspective view which shows the principal part structure of the screen printer concerning this Embodiment. It is a block diagram which shows the hardware constitutions of the screen printer concerning this Embodiment. It is a flowchart which shows operation | movement of the screen printer concerning this Embodiment. It is a figure explaining the inspection point of a board | substrate. It is a figure explaining grouping of an inspection point. It is a schematic diagram which shows the visual field size of a printing inspection camera. It is a figure explaining the inspection point of a board | substrate. It is a figure explaining the printing test | inspection performed for every group. It is a flowchart which shows the mask test | inspection operation | movement of the screen printer concerning this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mounting line, 2 ... Screen printer, 3, 4 ... Mounter, 5 ... Reflow furnace, 6 ... Substrate conveyance conveyor, 10, 10a, 10b, 10m, 10n ... Substrate, 11 ... Inspection point, 12 ... Lead part, DESCRIPTION OF SYMBOLS 20 ... Table, 21 ... Base, 22 ... Base, 23 ... 1st intermediate plate, 24 ... 2nd intermediate plate, 25 ... Stage, 26 ... 1st Y-axis motor, 27 ... 1st Z-axis motor, 28 ... X-axis motor , 29 ... θ-axis motor, 30 ... screen mask, 31 ... printing hole, 40 ... squeegee device, 41 ... frame member, 42 ... blanket member, 43 ... first squeegee head, 44 ... second squeegee head, 46 ... second Y Axis motor, 47 ... 2nd Z-axis motor, 48 ... 3rd Z-axis motor, 50 ... Board recognition camera, 60 ... Print inspection camera, 70 ... Control device, 71 ... Motor drive unit, 72 Storage unit, 73 ... image processing unit, 74 ... I / O processing unit, 75 ... inspection judging unit, 76 ... display unit, 80 ... mask recognition camera, 81 ... actuator, 82 ... sensor, 83 ... display device.

Claims (8)

In a screen printing machine that prints a predetermined printing material on a substrate through an opening formed in a screen mask,
Storage means for storing a plurality of inspection points set on the substrate divided into a plurality of groups, or storing a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups; ,
Inspection means for inspecting a printed state for the substrate inspection points included in one of the groups for the substrate;
A screen printing machine comprising: changing means for changing a group to be inspected by the inspecting means for each of the arbitrary number of the substrates. A board camera for imaging the board after printing;
The screen printing machine according to claim 1, wherein the inspection unit inspects the substrate based on imaging data of the substrate camera. In a screen printing machine that prints a predetermined printing material on a substrate through an opening formed in a screen mask,
Storage means for storing a plurality of inspection points set on the screen mask divided into a plurality of groups or storing a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups When,
Inspection means for inspecting the state of the screen mask for the inspection points included in one of the groups each time an arbitrary number of the substrates are printed;
A screen printing machine comprising: changing means for changing a group to be inspected by the inspecting means every time an arbitrary number of the substrates are printed. A mask camera for imaging a surface of the screen mask that contacts the substrate;
The screen printing machine according to claim 3, wherein the inspection unit inspects the screen mask based on imaging data of the mask camera. In a screen printing inspection apparatus for inspecting a printed substrate through an opening formed in a screen mask with a predetermined printing material by a screen printer,
Storage means for storing a plurality of inspection points set on the substrate divided into a plurality of groups, or storing a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups; ,
Inspection means for inspecting a printed state for the substrate inspection points included in one of the groups for the substrate;
A screen printing inspection apparatus comprising: changing means for changing a group to be inspected by the inspection means for each arbitrary number of substrates. A board camera for imaging the board after printing;
The screen printing inspection apparatus according to claim 5, wherein the inspection unit inspects the substrate based on imaging data of the substrate camera. In a screen printing inspection method for inspecting a substrate on which a predetermined printing material is printed through an opening formed in a screen mask by a screen printer,
A plurality of inspection points set on the substrate are divided into a plurality of groups and stored, or a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups are stored. Steps,
A second step of inspecting a printing state for the inspection points included in one of the groups per substrate;
A screen printing inspection method comprising: a third step of changing the group to be inspected in the second step for every arbitrary number of the substrates. In a screen printing inspection method for inspecting the screen mask of a screen printing machine that prints a predetermined printing material on a substrate through an opening formed in the screen mask,
A plurality of inspection points set on the screen mask are divided into a plurality of groups and stored, or a plurality of inspection points and a program for dividing the plurality of inspection points into a plurality of groups are stored. And the steps
A second step of inspecting the state of the screen mask for the inspection points included in one of the groups each time any number of the substrates are printed;
A screen printing inspection method comprising: a third step of changing the group to be inspected in the second step every time an arbitrary number of the substrates are printed.

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