JP4437723B2 - Screen printing device - Google Patents

Description

  The present invention relates to a screen printing apparatus for applying paste such as cream solder to a substrate such as a printed circuit board.

  Conventionally, a mask sheet (hereinafter referred to as a mask) is placed on a substrate set on a stage, and a paste such as cream solder or conductive paste supplied on the mask is expanded with a squeegee, thereby opening the mask. A screen printing apparatus that applies (prints) a paste to a predetermined position on a substrate via a section is generally known.

  Conventionally, this type of screen printing apparatus has a head provided with a pair of squeegees having different inclination directions so that the squeegee can be moved up and down, and pastes paste by alternately using the pair of squeegees while reciprocating the head along the mask. Although it was the mainstream to expand, in this device it is difficult to keep the printing load in the forward and backward directions uniform because each squeegee is raised and lowered separately, and the degree of freedom of the contact angle of the squeegee with respect to the mask is small There were problems such as.

Therefore, in recent years, as disclosed in, for example, Patent Document 1, a screen printing apparatus has been proposed in which a squeegee is supported so as to be swingable around an axis (support axis) parallel to the longitudinal direction of the head. According to this device, the contact angle with respect to the mask (the angle between the squeegee and the mask sheet surface) can be arbitrarily set simply by driving the squeegee around the axis, and the squeegee can be driven up and down by a single mechanism. It becomes easy to maintain the printing load at the time of restoration.
JP-A-10-323964

  By the way, in a screen printing device, when the paste is expanded with a squeegee, the paste may protrude to both sides in the longitudinal direction of the squeegee and be wasted, or may adhere to unnecessary portions on the mask. A side plate (lateral leakage prevention plate) is provided on both outer sides in the longitudinal direction of the squeegee, and the lateral leakage of the paste is prevented by sliding the lateral leakage prevention plate with a mask together with the squeegee.

  Therefore, the device as disclosed in Patent Document 1 that can arbitrarily set the contact angle of the squeegee also ensures the degree of freedom of the contact angle as described above, while at the same time being set to any contact angle. However, Patent Document 1 does not disclose anything about this point.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to reliably prevent lateral leakage of paste in a screen printing apparatus that supports a squeegee so as to be swingable with respect to a head.

In order to solve the above-described problems, a screen printing apparatus according to the present invention is a squeegee that can be rotated around a support axis perpendicular to the moving direction of a head that relatively reciprocates along a mask sheet superimposed on a substrate. An assembling portion is provided, and an elongated squeegee is assembled in the squeegee assembling portion in a direction parallel to the support shaft, and the squeegee is moved forward and backward by the operation of the squeegee assembling portion. In the screen printing machine configured to perform the printing operation while reversing the tilt direction of the squeegee , the squeegee assembling portion is provided with fulcrum shafts parallel to the support shaft and arranged on both outer sides in the longitudinal direction of the squeegee. side leakage preventing plates that prevents flow into the side of the paste Te is the is the fulcrum axis swingably supported on the side leakage prevention plate is in sliding contact with the mask sheet during the forward movement the A slidable contact surface and a second slidable contact surface that is slidably contacted with the mask sheet during backward movement, and the squeegee is pressed against the mask sheet in a state where the squeegee assembly portion is held at a predetermined angle around the support shaft. In response to pressing the squeegee against the mask sheet from a neutral position that is a position of the side leakage preventing plate with respect to the squeegee assembled portion in a state where the side leakage preventing plate is separated from the mask sheet. The side leakage preventing plate at the neutral position until the angle formed by the mask sheet side sliding contact surface of the first sliding contact surface and the second sliding contact surface becomes zero. The lateral leakage prevention plate is supported so as to be swingable about the fulcrum axis by an angle formed by the sliding contact surface on the mask sheet side and the mask sheet (Claim 1).

  According to this screen printing apparatus, the lateral leakage prevention plates are provided on both outer sides in the longitudinal direction of the squeegee, and the lateral leakage prevention plates are configured to be relatively displaceable with respect to the squeegee. While making contact with the mask sheet surface at an angle, the side leakage prevention plate can be appropriately slidably contacted with the mask sheet surface without being restricted by the angle. Therefore, the lateral leakage of the paste can be reliably prevented regardless of the contact angle.

In addition, as a specific configuration, for example, in the screen printing apparatus according to claim 1, the lateral leakage prevention plate includes the support shaft and the fulcrum shaft in a state where the lateral leakage prevention plate is separated from the mask sheet. In a state where the first sliding contact surface and the second sliding contact surface are provided symmetrically with respect to a connecting line , and the side leakage prevention plate is in the neutral position, the first sliding contact surface and the squeegee are The angle formed and the angle formed between the second slidable contact surface and the squeegee can be made equal (claim 2).

  In this screen printing apparatus, the printing operation is advanced by reversing the tilt direction of the squeegee during forward and backward movement of the head while reciprocating. The reversal of the tilt direction of the squeegee is performed by rotating the squeegee assembly part with respect to the head. At this time, the side leakage prevention plate is also reversed together with the squeegee assembly part. The side leakage prevention plate is slidably contacted with the mask sheet surface via the first sliding contact surface during forward movement, while the side leakage prevention plate is slidably contacted with the mask sheet surface via the second sliding contact surface during backward movement. It becomes. At this time, the side leakage prevention plate is supported so as to be able to swing relative to the squeegee assembly portion, so that the side leakage prevention plate is not restricted by the contact angle of the squeegee during any reciprocal movement. Will slidably contact the mask sheet surface.

  In the case of this configuration, it is preferable that the side leakage preventing plate is supported so as to be elastically swingable around the fulcrum shaft with respect to the neutral position (claim 3).

  According to this configuration, when the side leakage prevention plate is rotated relative to the squeegee assembly portion from the neutral position, a restoring force (elastic force) for returning the side leakage prevention plate to the neutral position is the side leakage prevention plate. Therefore, it is possible to press the side leakage prevention plate against the mask sheet surface by this restoring force. That is, the side leakage prevention plate can be slidably brought into sliding contact with the mask sheet surface by bringing the side leakage prevention plate into pressure contact with the mask sheet surface in this way.

In the screen printing apparatus of the present invention , the squeegee holder that holds the squeegee is detachably attached to the squeegee attaching portion, whereby the squeegee is attached to the squeegee attaching portion, and further the lateral squeegee is attached. It is preferable that the side leakage prevention plate is supported by the squeegee assembly part via the squeegee holder by assembling the leakage prevention plate to the squeegee holder.

  According to this configuration, it is possible to easily and quickly replace the squeegee and the side leakage prevention plate with respect to the head by previously incorporating the side leakage prevention plate suitable for the size and contact angle of the squeegee into the squeegee holder. .

  According to the screen printing apparatus according to any one of claims 1 to 4, while the squeegee is brought into contact with the mask sheet surface at a predetermined contact angle, the side leakage preventing plate is appropriately slidably brought into contact with the mask sheet surface without being restricted by the angle. Therefore, while ensuring the degree of freedom of the contact angle of the squeegee with respect to the mask sheet, it is possible to satisfactorily prevent the wasteful consumption due to the lateral leakage of the paste and the adhesion of the paste to unnecessary portions of the mask sheet.

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

  1 and 2 show the configuration of the head portion of the screen printing apparatus according to the present invention. As shown in FIG. 1, the screen printing apparatus is supported by a traveling unit 2 that reciprocally moves along a mask sheet M superimposed on a substrate (not shown), and is movable up and down with respect to the traveling unit 2. It has a head 1 composed of an elevating unit 4, and slides along the surface of the mask sheet M in a state where a squeegee 31 described later is pressed against the mask sheet M at a predetermined angle and pressure by the operation of the head 1. In this way, paste such as cream solder or conductive paste supplied on the mask sheet by this sliding is expanded.

  The traveling unit 2 is provided so as to be able to travel in one direction (left and right in FIG. 1) along a rail that is not shown in the figure. For example, the traveling unit 2 is connected to a ball screw shaft that is rotationally driven using a motor as a drive source. The ball screw shaft is configured to reciprocate along the rail in accordance with forward / reverse rotation driving of the ball screw shaft. In the following description, for the sake of convenience, the traveling direction of the traveling unit 2 will be referred to as the X-axis direction, and the direction orthogonal to this on the horizontal plane will be referred to as the Y-axis direction (illustrated in FIG. 1).

  The lifting / lowering unit 4 is attached to the lower end of the rod 3 connected to a lifting / lowering driving mechanism that uses a motor or air cylinder as a driving source mounted on the traveling unit 2. It is driven up and down.

  The elevating unit 4 holds the squeegee 31 for expanding the paste supplied on the mask sheet M. The squeegee 31 is integrally incorporated in the squeegee unit 30. Hereinafter, the squeegee unit 30 will be described in detail together with a specific configuration of the elevating unit 4.

  As shown in FIG. 1, the elevating unit 4 has a main frame 10 made of, for example, aluminum connected to the rod 3. A support portion 14 with a pressure sensor 12 such as a load cell interposed is suspended from the lower surface of the frame 10, and a sub-frame 16 is swingably supported by the support portion 14. Specifically, a first support shaft 15 extending in the X-axis direction protrudes from the support portion 14, and the sub-frame 16 is attached to the first support shaft 15 via a bearing or the like, so that the frame 16 is attached to the first support shaft 15. 1 is supported so as to be swingable around a support shaft 15.

  The subframe 16 is rotatably supported by a unit assembly member 18 corresponding to the squeegee assembly portion according to the present invention, and a drive mechanism for driving the unit assembly member 18 is mounted.

Unit assembly member 18, as shown in FIG. 3, Y-axis direction in an elongated rectangular plate member, rotates in the sub-frame 16 via the supporting portion 18a which is erected in the longitudinal direction intermediate portion thereof Supported as possible. Specifically, the second support shaft 17 extending in the Y-axis direction is supported by the subframe 16 in a state of being rotatable around the axis, and the unit assembly member 18 is supported by the second support shaft 17 via the support portion 18a. By mounting, the unit assembling member 18 is swingably supported with respect to the subframe 16.

  The second support shaft 17 that supports the unit assembling member 18 passes through the subframe 16 and protrudes to the opposite side, and a pulley 24 is attached to the protruding portion. A servo motor 22 as a drive source is fixed to the sub-frame 16, and a drive belt 26 is attached across the pulley 23 attached to the output shaft of the motor 22 and the pulley 24. The drive belt 26 is stretched by the tension pulley 28 being pressed from the outer peripheral side of the lever. That is, the servo motor 22, the pulleys 23, 24, 28, the drive belt 26, and the like constitute the drive mechanism, and the operation of the servo motor 22 causes the unit assembly member 18 to rotate forward and backward around the second support shaft 17. It is designed to be driven.

  A squeegee unit 30 is detachably attached to the unit assembly member 18. As shown in FIGS. 3 and 4, the squeegee unit 30 includes a squeegee 31 and a squeegee holder 32 that holds the squeegee 31.

  The squeegee holder 32 is an elongated plate member in the Y-axis direction made of a light alloy such as an aluminum alloy. On the other hand, the squeegee 31 is a rectangular plate-like member made of, for example, hard urethane or stainless steel and elongated in the Y-axis direction, and is held by the holder 32 in a state of being superimposed on the squeegee holder 32 as shown in FIG. .

  Of the squeegee holder 32, a surface 32a opposite to the surface on which the squeegee 31 is held is an assembly surface for the unit assembly member 18 (hereinafter referred to as an assembly surface 32a). A pair of screw shafts 36 project integrally from the assembly surface 32a at a predetermined interval in the Y-axis direction, and an operation nut 37 is screwed and attached to the tips of the screw shafts 36. As will be described later, the squeegee unit 30 is fixed to the unit assembling member 18 by these screw shafts 36 and the like.

  At both ends in the longitudinal direction of the squeegee holder 32, side leakage prevention plates 34 are further provided. These lateral leakage prevention plates 34 are members for preventing the paste from flowing and leaking (running away) to the side of the squeegee 31 (the Y axis direction outer side) during the printing operation.

  As shown in FIGS. 1 and 5, the side leakage prevention plates 34 are a pair that approach each other from the base end portion toward the tip end portion (in FIG. 5, the upper portion to the lower portion) with a center line L (shown in FIG. 1) as a boundary. This is a substantially trapezoidal plate-like member having a slidable contact surface 34a (first and second slidable contact surfaces), which is on the center line L and whose base end is a fulcrum (rotation center). And is elastically held at a predetermined neutral position.

  More specifically, as shown in FIG. 5, the side leakage preventing plate 34 is formed with a through hole 34c penetrating in the thickness direction at the center of the base end portion, and a collar 39 is inserted into the through hole 34c. ing. A fixing bolt 40 (fulcrum shaft) is inserted into the through hole 34 c (collar 39) from the outside of the side leakage prevention plate 34, and this fixing bolt 40 is screwed into the screw hole 32 b of the squeegee holder 32. Accordingly, the side leakage prevention plate 34 is assembled to the end of the squeegee holder 32 in a state of being rotatable around the fixing bolt 40.

  Further, each lateral leakage prevention plate 34 has a base end portion (through hole 34c) formed by cutting a part of the outer surface side thereof, that is, the surface opposite to the assembly surface side with respect to the squeegee holder 32 in the thickness direction. A pair of contact surfaces 34b are formed which are spread evenly from the first portion toward the distal end. An urging member 38 having a pair of leaf spring pieces 38a extending in a substantially inverted V shape (inverted V shape in FIG. 5) is fixed to the squeegee holder 32, and each of the plates of the urging member 38 is The tip of the spring piece 38a is in contact with each contact surface 34b of the side leakage prevention plate 34 from both sides of the fixing bolt 40 as shown in FIGS. That is, in the state where no external force acts on the side leakage prevention plate 34, the elastic force of each leaf spring piece 38a acts on the side leakage prevention plate 34 evenly, whereby the angle formed between the squeegee 31 and each sliding contact surface 34a. The lateral leakage prevention plate 34 is held at a position where both α (hereinafter referred to as sliding contact surface angle α) are equal (referred to as a neutral position). On the other hand, an external force is applied only to the lateral leakage prevention plate 34 while the squeegee holder 32 is restrained. When acted, the side leakage prevention plate 34 rotates against the elastic force of the leaf spring piece 38a, and when this external force is removed, the side leakage prevention plate 34 rotates counterclockwise by the elasticity of the leaf spring piece 38a. As a result, the side leakage prevention plate 34 is configured to return to the neutral position.

  In the present embodiment, the squeegee unit 30 is configured such that the sliding contact surface angle α is 70 ° in the state where the side leakage preventing plate 34 is in the neutral position as described above.

  The squeegee unit 30 as described above is assembled and fixed to the unit assembling member 18 by the operation nut 37 in a state of being superimposed on the unit assembling member 18.

  Specifically, a pair of notches 20 corresponding to the screw shafts 36 of the squeegee unit 30 are formed at both ends in the Y-axis direction of the unit assembly member 18 as shown in FIG. On the other hand, with each screw shaft 36 inserted from the side, the squeegee unit 30 is superimposed on the lower surface (lower surface in FIG. 3) of the unit assembly member 18 via the assembly surface 32a. By tightening the nut 37, the squeegee unit 30 is retracted and fixed to the lower surface of the unit assembly member 18. In short, the squeegee unit 30 is fixed to the unit assembly member 18 by sandwiching the unit assembly member 18 between the operation nut 37 and the squeegee unit 30.

  The specific shape of the notch 20 of the unit assembling member 18 is such that, for example, the squeegee 31 is positioned so that the squeegee 31 is positioned in a state where the screw shaft 36 is abutted against the back end of the notch 20. Width, depth (guide depth) dimensions, etc. are set.

  Next, the function and effect of the screen printing apparatus as described above will be described.

  In this screen printing apparatus, preparation work for assembling the squeegee unit 30 to the unit assembling member 18 of the head 1 is performed prior to the start of work. This assembly is an operator task. In this case, the operator overlaps the unit assembly member 18 with the squeegee unit 30 while inserting each screw shaft 36 of the squeegee unit 30 into the notch 20 of the unit assembly member 18. Then, by tightening the operation nut 37 and fixing the squeegee unit 30 to the unit assembling member 18, the squeegee unit 30 can be easily and quickly assembled to the head 1. It is assumed that the substrate is already positioned at a predetermined reference position in a state where the mask sheet M is overlaid.

  When the preparatory work is completed, the head 1 is operated based on an operation input instruction for starting the work by the operator, whereby the printing work is started in the screen printing apparatus.

  Specifically, first, the squeegee 31 is disposed above a predetermined work start position by the operation of the traveling unit 2, and the squeegee unit 30 is rotationally displaced by the operation of the unit assembly member 18, for example, in FIG. When 31 moves to the right, the squeegee 31 is set in a state of being bent forward (acute angle) toward the traveling direction as indicated by a solid line in FIG. At this time, the squeegee 31 is set to the attack angle β during the printing operation. The attack angle β is a contact angle of the squeegee 31 with respect to the mask sheet M, that is, an inclination angle of the squeegee 31 with respect to the mask sheet M when the paste is expanded by bringing the squeegee 31 into contact with the mask sheet M (FIG. 6 (a)).

  Next, the squeegee 31 is set at a height position where the edge portion abuts on the contact point on the mask sheet M by the operation (lowering) of the elevating unit 4. At this time, the squeegee 31 is brought into pressure contact with the mask sheet M at a preset pressure by driving and controlling the elevating unit 4 based on the detection value by the pressure sensor 12.

  When the squeegee 31 is set at a height position in contact with the mask sheet M as described above, the side leakage preventing plate 34 is interposed through the sliding contact surface 34a on one side as shown in FIG. In this embodiment, the side leakage prevention plate 34 is formed so as to be rotatable as described above. As a result, within a predetermined angle (in this embodiment, 40 ° to 70 °). If the attack angle β is any angle, the side leakage prevention plate 34 will appropriately come into contact with the mask sheet M without a gap. Specifically, for example, when the attack angle β = 70 °, the sliding contact surface angle α of the side leakage prevention plate 34 is “70 °” as described above, so that the squeegee 31 is brought into contact with the mask sheet M. As shown in FIG. 6A, the side leakage preventing plate 34 comes into contact with the mask sheet M through the assembly surface 32a while maintaining the neutral position. On the other hand, when attack angle β <sliding contact surface angle α, for example, when attack angle β = 60 °, 40 °, when squeegee 31 is brought into contact with mask sheet M, FIGS. 6 (b) and 6 (c). As shown in FIGS. 4A and 4B, the side leakage prevention plate 34 is rotationally displaced from the neutral position against the elastic force of the leaf spring piece 38a, and comes into contact with the mask sheet M in this state. In this case, the lateral leakage prevention plate 34 is pressed against the mask sheet M with respect to the mask sheet M by an elastic force corresponding to the bending of the leaf spring piece 38a.

  When the squeegee 31 is pressed against the predetermined contact point in this way, paste is supplied onto the mask sheet M by a supply device (not shown), and the squeegee 31 is moved in the X-axis direction by the operation of the traveling unit 2. By (forward movement), the paste on the mask sheet M is expanded by the squeegee 31. At this time, the lateral leakage prevention plate 34 prevents the lateral leakage of the paste, thereby appropriately expanding the paste.

When the squeegee 31 reaches the end position, the tilting direction of the squeegee 31 is switched as shown by a two-dot chain line in FIG. The direction of the prevention plate 34 is switched. Then, after the squeegee 31 is set at a height position where it abuts on the contact point on the mask sheet M as described above, the squeegee 31 moves in the X-axis direction. 31. At this time, the side leakage prevention plate 34 is in pressure contact with the mask sheet M through the other sliding contact surface 34a, that is, the sliding contact surface 34a on the side different from the forward movement, so that the paste can be removed as in the forward movement. Side leakage will be prevented.

  Thereafter, the paste is expanded by reciprocating the squeegee 31 along the mask sheet M while reversing the direction of the squeegee 31 as described above, and as a result, the paste is applied to the substrate through the opening formed in the mask sheet M. Is applied (printed).

  When this reciprocation is repeated a predetermined number of times, the printing operation is completed, the squeegee 31 is reset to a predetermined home position, and a series of printing operations by the screen printing apparatus is completed.

  After the printing operation is completed, the squeegee unit 30 is replaced with one corresponding to the next production (next lot), that is, one holding the squeegee 31 corresponding to the next production as necessary. This work is the work of the operator as described above. In this case, the operator loosens the fixing bolt 40 of the squeegee unit 30 to release the fixed state with respect to the unit assembling member 18, and then into the notch 20. By pulling the squeegee unit 30 away from the unit assembly member 18 along the squeegee unit 30, the squeegee unit 30 can be easily and quickly detached from the head 1.

  As described above, in this screen printing apparatus, the lateral leakage prevention plates 34 are provided on both outer sides in the longitudinal direction of the squeegee 31, and these lateral leakage prevention plates 34 can be displaced relative to the squeegee 31. Is configured to be swingable around the fixing bolt 40 with respect to the unit assembly member 18, so that the attack angle β is any angle within a certain angle (an angle of 40 ° to 70 °). Even in this case, the side leakage preventing plate 34 is appropriately brought into contact with the mask sheet M without any gap, thereby preventing the side leakage of the paste. Accordingly, while maintaining the degree of freedom of the attack angle β (contact angle) of the squeegee 31 with respect to the mask sheet M, it is possible to satisfactorily prevent wasteful consumption due to side leakage of the paste and adhesion of the paste to unnecessary portions of the mask sheet M. can do.

  In particular, in this apparatus, the side leakage prevention plate 34 is provided by the leaf spring piece 38a so as to be elastically swingable with respect to the neutral position, and if the attack angle β is less than 70 °, as described above. The side leakage prevention plate 34 is rotationally displaced from the neutral position against the elastic force of the leaf spring piece 38a, and the side leakage prevention plate 34 is masked by the restoring force (the elastic force of the biasing member 38). Therefore, there is an advantage that the side leakage prevention plate 34 can be reliably pressed against the mask sheet M to prevent the side leakage of the paste.

  Further, in this apparatus, the squeegee 31 is held by the squeegee holder 32, the assembly (squeegee unit 30) is detachably attached to the unit assembling member 18, and the side squeegee holder 32 is prevented from side leakage. Since the plate 34 is assembled, there is an advantage that the replacement work of the squeegee 31 and the side leakage prevention plate 34 can be performed easily and quickly. That is, the shape and interval of the side leakage prevention plate 34 may be changed according to the size of the squeegee 31 and the attack angle β, but this configuration is suitable for the squeegee 31 and the size and attack angle β of the squeegee 31. Since the lateral leakage prevention plate 34 is incorporated in the squeegee holder 32 in advance, the lateral leakage prevention plate 34 can be replaced at the same time when the squeegee 31 is replaced. Compared to a configuration in which the squeegee 34 is attached and detached independently, the replacement work of the squeegee 31 and the side leakage prevention plate 34 can be performed easily and quickly.

  In particular, in this apparatus, the unit assembly member 18 is provided with the notch 20 as described above, while the squeegee unit 30 is provided with the screw shaft 36 to which the operation nut 37 is screwed, and the screw shaft 36 is inserted into the notch 20. However, after the squeegee unit 30 is overlaid on the unit assembling member 18, the squeegee unit 30 can be assembled and fixed to the head 1 simply by tightening the operation nut 37, and the squeegee unit 30 is loosened by loosening the operation nut 37. Since the squeegee unit 30 can be detached from the head 1 simply by pulling it away from the assembly member 18, the squeegee unit 30 (squeegee 31 and side leakage prevention plate 34) can be replaced very easily and quickly. There is an advantage that can be done.

  The above-described screen printing apparatus is an example of the screen printing apparatus according to the present invention, and the specific configuration thereof can be appropriately changed without departing from the gist of the present invention.

  For example, in the above-described embodiment, the lateral leakage prevention plate 34 is configured to support the elastically swingable manner so as to utilize the elastic force of the leaf spring piece 38a (the biasing member 38). For example, a configuration may be adopted in which a torsion coil spring is inserted into the fixing bolt 40 and the side leakage prevention plate 34 is supported in an elastically swingable manner by utilizing the elastic force of the coil spring. In short, any structure may be used as long as the elastic force is generated when the attack angle β <the sliding contact surface angle α, and the side leakage prevention plate 34 is in pressure contact with the sliding surface 34a.

  In addition to the configuration in which the biasing member 38 is provided and the lateral leakage prevention plate 34 is elastically swingably supported as described above, for example, lateral leakage prevention is performed within a certain range based on the neutral position. The plate 34 may be configured to swing by its own weight, and may be configured to contact the mask sheet M by its own weight when the squeegee 31 is brought into contact with the mask sheet M.

  In the above embodiment, the lateral leakage prevention plate 34 is provided on the squeegee holder 32 (squeegee unit 30) that can be attached to and detached from the head 1 (unit assembly member 18). The leakage prevention plate 34 may be provided directly on the unit assembly member 18. However, since the shape and interval of the side leakage prevention plate 34 may be changed according to the size of the squeegee 31 and the attack angle β, the side leakage prevention plate 34 as in the above embodiment is taken into consideration in consideration of workability at the time of replacement. Is preferably provided in the squeegee holder 32 (squeegee unit 30).

  In the above embodiment, the sliding contact surface angle α of the side leakage preventing plate 34 is configured to be 70 ° on the assumption that the attack angle β of the squeegee 31 is 70 ° to 40 °. The configuration of details such as the contact surface angle α can be appropriately changed according to the specific attack angle β of the squeegee 31 and is not limited to the embodiment.

  In this embodiment, the screen printing apparatus is configured such that the work surface of the squeegee 31 (that is, the surface for expanding the paste) is orthogonal to the rotational radius direction of the squeegee 31. Needless to say, the present invention can also be applied to a screen printing apparatus in which a squeegee is provided so that the work surface of the squeegee is substantially parallel to the rotational radius direction, as disclosed in Patent Document 1 of the related art. .

It is a side view which shows the head part of the screen printing apparatus which concerns on this invention. It is a perspective view which shows the raising / lowering unit of a screen printing apparatus. It is a perspective view of the raising / lowering unit which shows the state which removed the squeegee unit from the unit assembly | attachment member. It is a perspective view which shows the structure of a squeegee unit. It is a disassembled perspective view which shows the attachment structure of the side leakage prevention board in a squeegee unit. It is a schematic diagram which shows the positional relationship of the squeegee and side leakage prevention board at the time of a printing operation ((a) is an attack angle of 70 degrees, (b) is an attack angle of 60 degrees, (c) is an attack. The case where the angle is 40 ° is shown).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Head 2 Traveling unit 4 Lifting unit 18 Unit assembly member 20 Notch 22 Servo motor 30 Squeegee unit 31 Squeegee 34 Side leakage prevention plate 36 Screw shaft 40 Fixing bolt

Claims (4)

A squeegee assembling portion that is rotatable around a support shaft orthogonal to the moving direction is provided on a head that relatively reciprocates along a mask sheet that is superimposed on the substrate, and the squeegee assembling portion includes the support shaft and A screen in which elongated squeegees are assembled in parallel directions, and printing is performed while reversing the inclination direction of the squeegee during forward and backward movement of the head by the operation of the squeegee assembly part. In the printing press
A fulcrum shaft parallel to the support shaft is provided on the squeegee assembly part,
A lateral leakage prevention plate disposed on both outer sides in the longitudinal direction of the squeegee to prevent the paste from flowing laterally is supported so as to be swingable about the fulcrum shaft, and the lateral leakage prevention plate is A first slidable contact surface that slidably contacts the mask sheet, and a second slidable contact surface that slidably contacts the mask sheet when returning,
In a state where the squeegee assembling part is held at a predetermined angle around the support shaft, before the squeegee is pressed against the mask sheet, the squeegee is released from the mask sheet. When the squeegee is pressed against the mask sheet from the neutral position, which is the position of the side leakage prevention plate with respect to the assembly portion, the mask sheet side of the first sliding contact surface and the second sliding contact surface Until the angle between the sliding contact surface and the mask sheet becomes 0, the lateral leakage prevention plate is formed by an angle formed by the sliding contact surface on the mask sheet side of the lateral leakage prevention plate at the neutral position and the mask sheet. A screen printing apparatus, wherein the screen printing apparatus is supported so as to be swingable about the fulcrum shaft. The screen printing apparatus according to claim 1,
The lateral leakage prevention plate includes the first sliding contact surface and the second sliding contact surface with a line connecting the support shaft and the fulcrum shaft as a boundary in a state where the lateral leakage prevention plate is separated from the mask sheet. And the angle formed by the first sliding contact surface and the squeegee and the angle formed by the second sliding contact surface and the squeegee are equal to each other in a state where the side leakage prevention plate is in the neutral position. A screen printing apparatus characterized by that. The screen printing apparatus according to claim 1 or 2,
The screen printing apparatus, wherein the side leakage prevention plate is supported so as to be elastically swingable about the fulcrum shaft with respect to the neutral position. The screen printing apparatus according to any one of claims 1 to 3,
The squeegee holder that holds the squeegee is removably assembled to the squeegee assembling part so that the squeegee is assembled to the squeegee assembling part,
A screen printing apparatus, wherein the lateral leakage prevention plate is supported by the squeegee assembly portion via the squeegee holder by assembling the lateral leakage prevention plate to the squeegee holder.

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