JP5848566B2 - Screen printing machine and screen printing method - Google Patents

Description

  The present invention relates to a screen printing machine or a screen printing method, and more particularly to a screen printing machine or a screen printing method capable of reliably detecting when a plurality of printed circuit boards are supplied to the screen printing machine.

  A conventional screen printing machine includes a warp correction device that not only applies a coating agent to a printed circuit board but also generally presses the printed circuit board supported by the substrate support device from above to correct the warp. Such a screen printing machine is disclosed in Patent Document 1.

JP 2009-241268 A

  The conventional screen printing machine disclosed in Patent Document 1 only corrects the warping of the printed circuit board using an air cylinder. For this reason, even if a plurality of overlapping prints are supplied, a printing operation is performed, causing a printing defect.

  Accordingly, the present invention provides a highly reliable screen printing machine or screen printing method capable of detecting not only the warpage correction of a printed circuit board but also the supply of a plurality of overlapping printed circuit boards using the substrate warpage correction means. For the purpose.

In order to achieve the above object, the present invention has at least the following features.
The present invention mounts the printed circuit board on the substrate support unit, lowers the warpage correction body and presses the printed circuit board placed above to correct the printed circuit board warpage by the substrate correction unit , and then In a screen printing machine or a screen printing method for printing a print pattern of a screen on the printed circuit board, the distance from the printed circuit board is measured by a distance sensor provided in a fixed portion that does not move with the warp correction body in the substrate correction unit. A first feature is to detect directly or indirectly and to determine that a plurality of the printed circuit boards are supplied to the substrate support unit based on a result of the detection.

The present invention also in that a pre Ki距 away sensor to a support frame for supporting vertically movably said warp correcting member and the second feature.
Furthermore, the present invention is characterized in that the distance sensor is provided on a fixed chute out of two chutes of a conveyance path for conveying the printed circuit board.

Further, the present invention has a fourth feature that the distance sensor is a light detection distance sensor.
Furthermore, the present invention, the light detection distance sensor detects directly the distance between the printed circuit board has a color or transparency of the printed circuit board in advance as data, to correct the distance on the basis of the data This is the fifth feature.

  According to the present invention, it is possible to provide a highly reliable screen printing machine or screen printing method capable of detecting not only the warpage correction of a printed circuit board but also the supply of a plurality of overlapping printed circuit boards using the substrate warpage correction means. .

It is a figure which shows the side view of the screen printer which is embodiment of this invention. It is a top view of the substrate correction unit which is an example in the screen printer of the embodiment of the present invention. FIG. 3 is a side view schematically showing a state before the substrate correction unit presses the printed circuit board, as viewed from the AA cross section shown in FIG. 2. FIG. 3 is a side view schematically showing a state in which the substrate correction unit is pressing the printed circuit board as viewed from the AA cross section shown in FIG. 2. FIG. 3 is a side view schematically showing a state in which two printed circuit board correction units are pressing a printed circuit board supplied and viewed from the AA cross section shown in FIG. 2. It is a figure which shows the processing flow of operation | movement of the screen printer which is embodiment of this invention, and the detection of two printed circuit boards.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a screen printing machine 100 according to an embodiment of the present invention. The screen printing machine 100 is for printing on the printed circuit board P with cream solder as a coating agent. The screen printing machine 100 has a substrate support unit 2 installed on the apparatus main body 1 and a movement for moving in the Y-axis direction (left-right direction in FIG. 1) disposed above the substrate support unit 2 and extending in the horizontal direction. A screen 3 supported by a screen support means (not shown) provided with a mechanism, and a printed circuit board P placed between the substrate support unit 2 and the screen 3 and placed on the substrate support unit 2 is imaged. An imaging camera 8 that performs correction, a substrate correction unit (substrate warpage correction means) 4 that corrects warpage by pressing a printed circuit board P placed on the substrate support unit 2 from above, and a screen 3. And a printing mechanism 6 provided with a squeegee 5.

  The substrate support unit 2 includes a movement mechanism (not shown) that can move in the X-axis direction (direction perpendicular to the paper surface), the angle direction in the horizontal plane of XY, and the Z-axis direction (vertical direction above and below the paper surface), and printing. A substrate transport mechanism (not shown) for transporting the substrate P in the X-axis direction, a backup table 2A having a backup pin for supporting the printed circuit board P from below and movable in the Z-axis direction, and the printed circuit board P sideways And a pair of support chutes 2B and 2C which are sandwiched and supported (clamped).

  In order to correct the warp of the printed circuit board P on the backup table 2A, the substrate correction unit 4 is arranged in the Y-axis direction (see FIG. 1) between a position below the screen 3 and a position retracted from the screen 3 (position shown in FIG. 1). 1 and the substrate correction unit 4 can be moved in the Z-axis (vertical direction).

  The printing mechanism 6 includes a squeegee 5 for printing cream solder on the printed circuit board P, a moving mechanism for moving in the Y-axis direction, and a vertical moving mechanism for moving the squeegee 5 in the Z-axis (vertical) direction. And.

Next, the further structure and operation | movement of the board | substrate correction unit 4 are demonstrated using FIGS. The substrate correction unit 4 corrects the warp of the printed circuit board P before applying the coating agent on the printed circuit board P. For this purpose, the substrate correction unit 4 moves between the retracted position shown in FIG. 1 and the substrate support unit 2. 2 is a plan view of the substrate correction unit 4. The left part of FIG. 2 is the front side (the paper surface side of FIG. 1) and the right part is the rear side (the back side of FIG. 1). FIG. 3 is a side view schematically showing a state before the substrate correction unit 4 presses the printed circuit board P, as viewed from the AA cross section shown in FIG.
FIG. 4 is a side view schematically showing a state in which the substrate correction unit 4 is pressing the printed board, as viewed from the AA cross section shown in FIG.

  The support frame 10 has an edge (a U-shape in plan view) on the left, right, and top of FIG. Further, the support frame 10 has frame support pieces 11 (11a to 11d) having an L-shaped cross section standing and fixed at the four corners thereof. The warp correction body 12 is supported by the support frame 10 so as to be vertically movable, and is moved up and down in the Z-axis direction of FIG. 1 in order to press the printed circuit board P by the air cylinder 17 (drive source) shown in FIG. The warp correction body 12 of the present embodiment has a function of moving up and down and a warp correction function of correcting the warp of the printed circuit board P. There are various sizes and thicknesses of the printed circuit board P. The printed circuit board P may be separated into a lifting plate having a function of moving up and down and a warp correction body suitable for the printed circuit board P, and the warpage correction body may be detachable from the lifting board.

Hereinafter, an elevating mechanism in which the warp correction body 12 moves up and down with respect to the support frame body 10 will be described mainly with reference to FIG. 2 with reference to FIGS. 3 and 4.
As shown in FIG. 3, the air cylinder 17 fixed to the support frame 10 rotates the contact member 16 in the direction of arrow B around the drive shaft 13. As shown in FIG. 2, the drive shaft 13 fixed to the contact member 16 is rotatably supported by support pieces 11a and 11b at both ends thereof. The drive shaft 13 has link pieces 14a and 14b whose one ends are fixed to the drive shaft 13 at both ends thereof. Support piece shafts 15a and 15b of a support piece 12A (see FIG. 3) provided on both sides of the warp correction body 12 are rotatably connected to the other ends of the link pieces 14a and 14b.
In FIG. 3, for easy understanding, the contact member 16 (and air cylinder 17) portion arranged at the center portion of the drive shaft 13 in FIG. 2 is based on the drive shaft 13 as indicated by a broken line. It is drawn by shifting upward. The same applies to FIGS. 4 and 5 described later.

  Therefore, as shown in FIG. 3, when the air cylinder 17 rotates the contact member 16 in the direction of arrow B around the drive shaft 13, the warp correction body 12 has support piece shafts 15 a and 15 d (see FIG. 3). Rotate in the direction of arrow C (counterclockwise) around 2). As shown in FIG. 2, the rotation in the direction of arrow C (counterclockwise) is transmitted to the corresponding support piece shafts 15b and 15c through the warp correction body 12, and the link pieces 14b and 14c are also moved in the direction of arrow C. The driven shaft 13j that rotates and is rotatably supported by the frame support pieces 11b and 11c also rotates in the direction of arrow C.

  As a result, the warp correction body 12 descends while moving in parallel with the stable rotation of the four support piece shafts 15a to 15d in the direction of arrow C, and shifts from the state of FIG. 3 to the state of FIG. Then, as shown in FIG. 4, the warp correction body 12 presses the printed board P supported by the backup table 2 </ b> A to correct the warp of the printed board P.

  In the above embodiment, the support pieces 11a to 11d fixed to the support frame 10 have the springs 19 stretched between the support portions 18a to 18d and the support piece shafts 15a to 15d provided on the support pieces 11a to 11d. Has been. The springs 19 bias the link pieces 14a to 14d so as to rotate in the direction of arrow D (clockwise) shown in FIG. Therefore, when the air cylinder 17 is not in operation, the air cylinder 17 is biased so as to approach the support frame 10, and when the air in the air cylinder 17 is released, the state shown in FIG. 4 returns to the state shown in FIG. Although the warp correction body 12 is returned to the original position using the spring 19 in the above, a cylinder operating in two directions by connecting the contact member 16 and the cylinder rod 17a in a rotatable manner may be used.

  Next, with reference to FIGS. 3 to 5, an example of detecting a plurality of boards using the board correction unit 4, particularly two printed boards that are highly likely to occur will be described. FIG. 5 is a side view schematically showing a state in which the substrate correction unit 4 is pressing the two printed circuit boards P supplied and viewed from the AA cross section shown in FIG.

  In the present embodiment, as shown in FIGS. 2 to 5, the distance sensor 20 is fixed to the support frame 10, and the distance to the warp correction body 12 instead of the printed board P is detected. In the present embodiment, the distance sensor 20 is a light detection type that detects a distance by light, such as a laser distance detection sensor.

  As described with reference to FIG. 3, at the time of pressing, the warp correction body 12 descends while moving in parallel in the direction of arrow C along with the rotation. On the other hand, the support frame 10 does not move. Here, for example, before the production of the substrate, the distance for one printed circuit board is detected in advance, and the detected distance is stored in the storage device. Then, the distance obtained by subtracting the allowable distance from the stored distance is defined as a normal distance Ls. When the detection distance L is larger than that, it is determined that there is one printed circuit board. )

The distance sensor 20 is provided on the side close to the reference side 2B , which is a fixed chute, of the pair of support chutes 2B and 2C that form the transport path of the printed board described in FIG. In the present embodiment, as shown in FIG. 2, the distance sensor 20 is provided on the left side of the support frame 10 on the paper surface. When the warp correction is performed by the substrate warp correction unit 4, the substrate transport width needs to be changed depending on the width of the substrate. When the width of the substrate is small, warpage occurs at a portion where the warp correction body 12 does not press the printed circuit board. Therefore, the distance is accurately measured at the place where the printed circuit board is pressed regardless of the substrate width.

In the above embodiment, the distance from the warp correction body 12 is detected using the light detection type, but the distance from the printed circuit board P may be directly detected. However, the color and transparency of the printed circuit board P to be used are various, and the detected height is not constant. In that case, the color and transparency of the printed circuit board P are previously stored as data, and the detection distance is corrected based on the data.
In other words, the embodiment for detecting the distance from the warp correction body 12 has an advantage that it can detect a substrate in which a plurality of sheets are stably overlapped regardless of the color and transparency of the printed board.

According to the present embodiment described above, a highly reliable screen printing machine or screen printing capable of detecting not only the warpage correction of the printed circuit board but also the supply of a plurality of overlapping printed circuit boards using the substrate warpage correction means. Can provide a method.
In addition, the method for detecting the distance from the warp correction body 12 in the embodiment described above is reliable regardless of the color and transparency of the printed circuit board and can stably detect a substrate in which a plurality of sheets are overlapped. High screen printer or screen printing method can be provided.

In the embodiment described above, the distance sensor 20 is fixed to the support frame 10, but it may be any place as long as it does not move together with the warp correction body 12 like the support frame 10 during substrate warp correction. For example, the imaging camera 8 of the substrate correction unit 4 shown in FIG.
In the embodiment described above, the light detection type is used as the distance sensor 20, but if the distance from the warp correction body 12 is measured, for example, an eddy current displacement sensor or an ultrasonic displacement sensor may be used. Good.

  Next, description will be made with reference to FIG. 6 showing a processing flow of the operation of the screen printing machine 100 according to the embodiment of the present invention and detection of two printed boards. In the following description, in each symbol, the suffixes a to d are omitted to indicate the overall movement or configuration of the symbol.

  First, the printed circuit board P is supplied to the support chutes 2B and 2C of the substrate support unit 2 by a transport device (not shown), and is locked and positioned by a stopper pin (not shown) (Step 30). Then, the substrate correction unit 4 moves from the retracted position shown in FIG. 1 to the upper part of the printed circuit board P between the screen 3 and the substrate support unit 2 (Step 31).

  Next, in FIG. 3, first, the air cylinder 17 is operated, and the expanded cylinder rod 17 a presses the contact member 16 fixed to the drive shaft 13, against the urging force of the spring 19 and the drive shaft 13 and The link piece 14 is rotated in the direction of arrow C (counterclockwise), and the warp correction body 12 rotatably connected to the link piece 14 via the support piece shaft 15 is lowered (Step 32), and the substrate support unit 2 is backed up. The table 2A is raised (Step 33). Note that Step 32 and Step 33 may be performed in reverse.

  Thereafter, the printed board P is sandwiched between the backup table 2A and the warp correction body 12 of the board correction unit 4, and this state is maintained for a certain period of time to correct the warp of the printed board P (Step 34).

  Next, the distance L to the warp correction body 12 is detected by the distance sensor 20, and it is determined whether or not the distance is equal to or greater than the normal distance Ls indicating one printed circuit board (Step 35). If the detected distance L is less than or equal to the normal distance Ls, it is determined that two or more printed circuit boards P have been supplied (Step 36), and the printed circuit boards P determined to be two or more are discharged (Step 36). Then, it returns to Step30 and the process of the new printed circuit board P is performed.

  On the other hand, when the detection distance L is greater than or equal to the normal distance Ls. The cylinder rod 17 a is retracted by operating the air cylinder 17, and the drive shaft 13 and the link piece 14 are rotated in the direction of arrow D (clockwise) shown in FIG. Then, the warp correction body 12 rotatably connected to the link piece 14 is raised (Step 38), and the substrate correction unit 4 is retracted from the screen 3 (Step 39).

  Next, the support chute 2B and the backup table 2A are raised (Step 40), the printed circuit board P comes into contact with the lower surface of the screen 3, the printing mechanism 6 is operated, and the squeegee 5 removes the cream solder from the printing pattern hole of the screen 3. It is applied and printed on the printed circuit board P (Step 41). After this printing, the support chute 2B and the backup table 2A of the substrate support unit 2 are lowered and separated (Step 42). Finally, it is determined whether the predetermined number of sheets has been implemented. If it has been implemented, the process is terminated without returning to Step 30.

  According to the embodiment of the present invention described above, it is possible to provide a highly reliable screen printing method capable of detecting not only the warping correction of a printed board but also the supply of a plurality of printed boards.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention is not limited to the various embodiments described above without departing from the spirit of the present invention. It encompasses alternatives, modifications or variations.

1: Device main body 2: Substrate support unit 2A: Backup table 2B: Support chute 3: Screen 4: Substrate correction unit 5: Squeegee 6: Printing mechanism 8: Imaging camera 10: Support frame 11, 11a to 11d: Frame support Piece 12: Warp correction body 13: Drive shaft 13j: Drive shaft 14, 14a to 14d: Link piece 15, 15a to 15d: Support piece shaft 16: Contact member 17: Air cylinder 18: Spring support portion 19: Spring 20: Distance sensor 100: Clean printing machine P: Printed circuit board

Claims (10)

A substrate support unit that supports the printed circuit board that has been conveyed; a warp correction body that presses the printed circuit board from above; and a lifting mechanism that raises and lowers the warpage correction body, and is placed on the substrate support unit. In a screen printing machine having a substrate correction unit for correcting warpage of a printed circuit board, and a printing mechanism for printing a print pattern of a screen on the printed circuit board,
A distance sensor that is provided in a fixed portion that does not move together with the warp correction body of the substrate correction unit, and that directly or indirectly detects a distance from the printed circuit board, and the substrate support based on a detection result of the distance sensor A screen printing machine characterized in that it is determined that a plurality of printed circuit boards overlapping with a unit have been supplied.   The screen printer according to claim 1, wherein the distance sensor is provided on a support frame that supports the warp correction body so as to be movable up and down.   The screen printing machine according to claim 1, wherein the distance sensor is provided on a fixed chute out of two chutes of a conveyance path that conveys the printed circuit board.   The screen printer according to claim 1, wherein the distance sensor is a light detection distance sensor. The light detection distance sensor detects directly the distance between the printed circuit board has a color or transparency of the printed circuit board in advance as data, and corrects the distance based on the data according Item 5. A screen printer according to item 4.   The screen printer according to claim 1, wherein the distance sensor is an eddy current displacement sensor or an ultrasonic displacement sensor. The printed board is placed on the board support unit, the warp correction body is lowered, the printed board placed above is pressed from above to correct the warp of the printed board by the board correction unit , and then the printed board is placed on the printed board. In a screen printing method for printing a print pattern of a screen,
The distance from the printed circuit board is detected directly or indirectly by a distance sensor provided in a fixed part that does not move with the warp correction body of the substrate correction unit, and the substrate support unit is detected based on the detection result. A screen printing method comprising determining that a plurality of overlapping printed circuit boards have been supplied. Screen printing method according to claim 7, characterized in that a pre Ki距 away sensor to a support frame for supporting vertically movably said warp correcting member.   The screen printing method according to claim 7, wherein the distance sensor is a light detection distance sensor. The light detection distance sensor detects directly the distance between the printed circuit board has a color or transparency of the printed circuit board in advance as data, and corrects the distance based on the data according Item 10. A screen printing method according to Item 9.

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