JP2010158867A - Screen printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen printing machine showing high transferability of solder to a circuit board irrespectively of the size of an electronic component. <P>SOLUTION: The screen printing machine 1 includes an inertial force-generating device 4 integrally giving inertial force to the circuit board B after solder printing and a screen mask 301 approximately contacting the circuit board B before plate removal in the lamination direction of the circuit board B and the screen mask 301 to improve transferability of the solder to the circuit board B. The inertial force given by the inertial force-generating device 4 pushes the solder to the circuit board B. Therefore the solder is fixed to the circuit board B. Accordingly the transferability of the solder to the circuit board B is improved irrespectively of the size of the electronic component. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a screen printing machine that prints solder on lands (circuit electrode portions) of a circuit board on which electronic components are mounted.

  In mounting electronic components, a method of soldering electronic components to a circuit board by a reflow method is used. That is, a method is used in which solder is first printed on a land of a circuit board, then an electronic component is mounted on the circuit board, and then the circuit board is heated to solder the electronic component to the land. In this series of steps, screen printers are used to print solder on circuit board lands.

  The screen printing machine includes a screen mask and a squeegee. During printing, the screen mask is disposed above the circuit board. The squeegee is disposed above the screen mask. The screen mask has a large number of printing openings. The opening for printing is opened corresponding to the solder printing scheduled position of the circuit board. The solder is disposed on the upper surface of the screen mask.

  When printing solder on a circuit board, first, the lower surface of the screen mask and the upper surface of the circuit board are brought into contact with each other. Next, the solder is pushed into the printing opening with a squeegee. The pressed solder passes through the printing opening and is transferred to the solder printing scheduled position on the circuit board. Thus, the solder is printed on the circuit board through the printing opening of the screen mask.

  FIG. 24 shows an enlarged schematic diagram of the circuit board after solder printing. The solder 100 has viscosity. For this reason, the solder 100 is bonded not only to the upper surface of the land 101 a of the circuit board 101 but also to the inner peripheral surface of the printing opening 102 a of the screen mask 102. Therefore, in order to transfer the solder 100 to the land 101a, when separating the screen mask 102 and the circuit board 101, that is, when separating the plate, the solder 100 is peeled off from the inner peripheral surface of the printing opening 102a. It is necessary to fix on the upper surface of the surface.

  Here, assuming that the area of the inner peripheral surface of the printing opening 102a is S100 and the opening area of the printing opening 102a is S101, the transferability of the solder 100 is improved when S101 / S100 is larger. That is, the transfer property of the solder 100 is improved when the shape of the printing opening 102a has a short axis and a large diameter, as compared with a case where the major axis has a small diameter. The reason is that the adhesive force of the solder 100 to the upper surface of the land 101a tends to be larger than the adhesive force of the solder 100 to the inner peripheral surface of the printing opening 102a.

JP 2006-142646 A

  Incidentally, in recent years, along with downsizing of electronic devices such as mobile phones, cases of mounting small electronic components (for example, electronic components having a size of 0.4 mm × 0.2 mm) on the circuit board 101 have increased. Yes. In order to mount a small electronic component on the circuit board 101, it is necessary to reduce the hole diameter of the printing opening 102a. For example, the hole diameter of the printing opening 102a needs to be about 0.2 mm. When the hole diameter of the printing opening 102a is reduced, the opening area S101 of the printing opening 102a is reduced accordingly. Therefore, in order to improve the transferability of the solder 100, it is necessary to reduce the area S100 of the inner peripheral surface of the printing opening 102a. That is, it is necessary to reduce the overall length of the printing opening 102a, that is, the thickness of the screen mask 102. As an example, when the thickness of the general-purpose screen mask 102 is about 0.12 mm, it is necessary to reduce the thickness of the screen mask 102 to about 0.08 mm in order to cope with a small electronic component.

  However, not only small electronic components but also large general electronic components conventionally used are mounted on the circuit board 101. In other words, electronic components of various sizes are mixed on the circuit board 101. For this reason, when the thickness of the screen mask 102 is set based on a small electronic component, the transfer amount (S101 × S100) of the solder 100 is insufficient for a general electronic component. Therefore, there is a possibility that the bonding force of general electronic components to the circuit board 101 is insufficient.

  Therefore, ideally, a general-purpose screen mask 102, in other words, a screen mask 102 having a thickness that can secure the transfer amount of the solder 100 required for a general electronic component, is used for a large electronic component. It is preferable that the solder 100 can be satisfactorily transferred not only to the land 101a but also to the land 101a for a small electronic component. In other words, even if S101 / S100 is small, it is preferable that the transferability of the solder 100 is high.

  In this regard, Patent Document 1 discloses a screen printing machine that extrudes the solder 100 from the printing opening 102a by air. In the screen printing machine described in this document, after the solder 100 is printed, the solder 100 is pushed out from the printing opening 102a by press-fitting air into the printing opening 102a to fix the solder 100 to the land 101a. Therefore, the solder 100 can be transferred not only to the large electronic component land 101a but also to the small electronic component land 101a.

  However, according to the screen printing machine described in the same document, when the adhesion between the screen mask 102 and the circuit board 101 after solder printing is poor, that is, when there is a gap between the lower surface of the screen mask 102 and the upper surface of the circuit board 101, There is a possibility that the air press-fitted into the printing opening 102a may leak from the gap. In this case, the solder 100 leaks from the gap together with the air, and the transfer shape of the solder 100 with respect to the land 101a may be disturbed. Further, when air is pressed into the printing opening 102a during the separation of the plate, the air may leak out from the gap between the lower surface of the screen mask 102 and the upper surface of the circuit board 101. That is, the transfer shape of the solder 100 with respect to the land 101a may be disturbed. Further, according to the screen printing machine described in the document, it is necessary to cover the screen mask 102 with a cover member from above to form a closed space in order to ensure air pressure. For this reason, the structure of the screen printer becomes large.

  The screen printing machine of the present invention has been completed in view of the above problems. Accordingly, an object of the present invention is to provide a screen printing machine having high transferability of solder to a circuit board regardless of the size of an electronic component.

  (1) In order to solve the above-described problem, the screen printing machine of the present invention includes a circuit board after solder printing and a screen mask before the plate separation that is substantially in contact with the circuit board. An inertial force generator that applies an inertial force integrally in the stacking direction to improve transferability of the solder to the circuit board is provided (corresponding to claim 1).

  Here, “substantially abut” means not only that the circuit board and the screen mask are in contact but also a small gap (a gap where solder can be printed) is interposed between the circuit board and the screen mask. Including the case.

  Here, the inertial force refers to a resistance force that tries to maintain the state before the external force is applied even when the external force is applied. The screen printing machine of the present invention includes an inertial force generator. The inertial force generator applies at least one of acceleration and deceleration to the circuit board and the screen mask in the stacking direction of the circuit board and the screen mask. That is, the inertial force generator applies an inertial force to the circuit board and the screen mask in the stacking direction of the circuit board and the screen mask. Due to the inertial force, the printed solder is pressed against the circuit board. That is, the solder is fixed on the circuit board. According to the screen printing machine of the present invention, the transferability of solder to a circuit board can be improved regardless of the size of the electronic component.

  Further, even when a minute gap is interposed between the circuit board and the screen mask, the stacking direction of the circuit board and the screen mask intersects with the extending direction of the gap. That is, the direction in which the inertial force and the extending direction of the gap intersect. For this reason, it is difficult for the solder to leak from the gap. Therefore, the transfer shape of the solder with respect to the circuit board is hardly disturbed.

  (2) Preferably, in the configuration of the above (1), the inertial force generation device applies at least one of acceleration and deceleration in a predetermined pattern to the circuit board and the screen mask. It is better to apply a force (corresponding to claim 2).

  When applying an inertial force by acceleration, for example, an acceleration that exceeds the deceleration in absolute value may be applied to the circuit board and the screen mask. When the inertia force is applied by the deceleration, for example, a deceleration exceeding the acceleration in absolute value may be applied to the circuit board and the screen mask.

  (3) Preferably, in the above configuration (1) or (2), the screen mask is further arranged so that the circuit mask is further disposed above the circuit board supporting member and the circuit board supporting member. It is preferable that the inertial force generator is configured to connect the circuit board and the screen mask so that the circuit board and the screen mask can be separated from each other. (Corresponding to claim 3).

  According to this configuration, the circuit board and the screen mask can be relatively separated and brought into contact with each other by the inertial force generator. For this reason, for example, at the time of circuit board imaging, the imaging device can be inserted between the circuit board and the screen mask. Further, the circuit board and the screen mask can be separated when the plate is separated. On the other hand, an inertial force can be integrally applied to the circuit board and the screen mask after printing and before separation of the plate.

  (4) Preferably, in the configuration of (3), the inertial force generation device moves in an axial direction of the shaft portion when the shaft portion is inserted and the shaft portion rotates around an axis. A ball screw device having a nut portion capable of connecting the nut portion and one of the substrate support member and the mask support member, and the substrate support member and the mask support member. The other is driven by the nut portion, and the ball screw device connects the nut portion and one of the substrate support member and the mask support member via the connection portion, and moves the nut portion. It is better to apply an inertial force integrally to the circuit board and the screen mask (corresponding to claim 4).

  The ball screw device includes a shaft portion, a nut portion, and a connecting portion. One of the substrate support member and the mask support member can be connected to and disconnected from the nut portion via the connecting portion. The other of the substrate support member and the mask support member is driven by the nut portion.

  According to this configuration, for example, when the circuit board is imaged or separated from the plate, the circuit board and the screen mask are separated by disconnecting the connection between one of the board support member and the mask support member and the nut portion. Can be made. More specifically, when the mask support member follows the nut portion, the connection portion blocks the connection between the nut portion and the substrate support member, whereby the circuit board and the screen mask can be separated. Further, when the substrate support member follows the nut portion, the connection portion blocks the connection between the nut portion and the mask support member, whereby the circuit board and the screen mask can be separated.

  On the other hand, after printing and before separating the plate, one of the substrate support member and the mask support member and the nut portion are connected to each other by a connecting portion, whereby an inertial force is applied integrally to the circuit board and the screen mask. be able to. More specifically, when the mask support member follows the nut portion, the connecting portion connects the nut portion and the substrate support member, so that an inertial force can be applied integrally to the circuit board and the screen mask. When the substrate support member is driven by the nut portion, the connecting portion connects the nut portion and the mask support member so that an inertial force can be applied integrally to the circuit board and the screen mask.

  (5) Preferably, in the configuration of (4), the substrate support member has a guided portion, and when the inertial force is applied integrally to the circuit board and the screen mask, the guided member is It is better to have a guide member having a guide portion on which the portion slides (corresponding to claim 5).

  According to this configuration, the operation direction of the substrate support member can be regulated by the guided portion and the guide portion. For this reason, the direction in which the inertial force can be regulated. Further, by adjusting the sliding distance between the guided portion and the guide portion, the moving distance (stroke) of the circuit board and the screen mask when applying the inertial force can be adjusted. That is, the maximum speed of the circuit board and the screen mask can be adjusted.

  (6) Preferably, in the configuration of (3), the inertial force generator moves in the axial direction of the shaft portion when the shaft portion is inserted and the shaft portion rotates around the axis. The first nut portion that can be moved, and the shaft portion is inserted and rotated around the axis so that the shaft portion can move in the axial direction of the shaft portion, and the shaft portion itself rotates around the axis of the shaft portion. A second nut portion that is movable in the axial direction of the shaft portion, and one of the substrate support member and the mask support member is driven by the first nut portion, The other of the substrate support member and the mask support member follows the second nut portion, and the biaxial ball screw device moves at least one of the first nut portion and the second nut portion. The Rukoto is better to adopt a configuration adding integrally inertial force and said circuit board the screen mask (corresponding to claim 6).

  The biaxial ball screw device includes a shaft portion, a first nut portion, and a second nut portion. One of the substrate support member and the mask support member is driven by the first nut portion. The other of the substrate support member and the mask support member is driven by the second nut portion.

  The first nut portion is movable in the axial direction of the shaft portion as the shaft portion rotates. Similar to the first nut portion, the second nut portion is movable in the axial direction of the shaft portion as the shaft portion rotates. Moreover, the second nut part is movable in the axial direction of the shaft part by rotating itself. That is, the second nut portion can move in the axial direction of the shaft portion not only when the shaft portion is rotating but also when the shaft portion is stopped. In other words, the first nut portion and the second nut portion can move independently of each other.

  For example, the first nut portion and the second nut portion can be moved in the same direction at the same speed. Further, the first nut portion and the second nut portion can be moved in the same direction at different speeds. Further, the first nut portion and the second nut portion can be moved in the opposite directions at the same speed. Moreover, a 1st nut part and a 2nd nut part can be moved at a different speed in the opposite direction.

  For this reason, the space | interval of a board | substrate support member and a mask support member can be freely adjusted simultaneously or with a predetermined time difference. Therefore, for example, when imaging a circuit board, a desired gap can be quickly secured between the circuit board and the screen mask. Further, at the time of plate separation, a desired plate separation speed (relative speed between the circuit board and the screen mask) can be ensured. On the other hand, an inertial force can be integrally applied to the circuit board and the screen mask after printing and before separation of the plate.

  According to the present invention, it is possible to provide a screen printer with high transferability of solder to a circuit board regardless of the size of electronic components.

It is a top view of the screen printer of a first embodiment. It is a right view of the screen printing machine. It is a model right view in the board | substrate fixing process of the screen printing machine. It is a model right view in the imaging process of the screen printing machine. It is a model right view in the plate matching process of the screen printing machine. It is a model right view in the transfer process 1st stage of the screen printing machine. It is a model right view in the transfer process 2nd stage of the screen printing machine. It is a model right view in the transfer process 3rd stage of the screen printing machine. It is a model right view in the transfer process 4th stage of the same screen printing machine. It is a model right view in the fixing process of the screen printing machine. It is a model right view in the plate separation process of the screen printing machine. It is a perspective view of the screen printer of a second embodiment. It is a right view of the upper part of the screen printing machine. FIG. 3 is an enlarged perspective view near the substrate support member of the screen printing machine. FIG. 3 is an enlarged perspective view of the vicinity of a mask support member and a squeegee member of the screen printing machine. It is an expanded sectional view in the frame XVI of FIG. It is an expanded sectional view in the frame XVII of FIG. It is a model right view in the board | substrate fixing process of the upper part of the screen printing machine. It is a model right view in the imaging process of the upper part of the screen printing machine. It is a model right view in the plate matching process of the upper part of the screen printing machine. It is a model right view in the transfer process of the upper part of the screen printing machine. It is a model right view in the fixing process of the upper part of the screen printing machine. It is a schematic diagram of the time-speed pattern employable in the fixing process of the screen printer of the present invention. It is an expansion schematic diagram of the circuit board after solder printing.

  Hereinafter, embodiments of the screen printing machine of the present invention will be described.

<First embodiment>
[Configuration of screen printer]
First, the configuration of the screen printing machine of this embodiment will be described. FIG. 1 shows a top view of the screen printing machine of the present embodiment. The mask support member 3 and the squeegee member 7 are omitted. FIG. 2 shows a right side view of the screen printing machine. The guided member 26 of the substrate support member 2 and the guide portion 50 of the guide member 5 are shown in a transparent manner. As shown in FIGS. 1 and 2, the screen printing machine 1 according to the present embodiment includes a substrate support member 2, a mask support member 3, a ball screw device 4, a pair of left and right guide members 5, a base 6, And a squeegee member 7.

(Base 6 and guide member 5)
The substrate 6 is arranged on the floor of the factory. The base 6 has a rectangular plate shape.

  Each of the pair of left and right guide members 5 has a rectangular plate shape. The pair of left and right guide members 5 protrude upward from the vicinity of both left and right edges of the upper surface of the base 6. A pair of front and rear guide portions 50 are recessed in the right surface of the left guide member 5. A pair of front and rear guide portions 50 are recessed on the left surface of the right guide member 5. The four guide portions 50 each have a groove shape extending in the vertical direction. Each of the four guide portions 50 accommodates guided portions 260 of the substrate support member 2 described later so as to be slidable in the vertical direction.

(Substrate support member 2)
The substrate support member 2 is supported by the base 6 so as to be movable in the vertical direction. The substrate support member 2 mainly includes a pair of front and rear side clamps 20, a pair of front and rear edge clamps 21, an upper table 22, an intermediate table 23, a lower table 24, a pair of front and rear belt conveyors 25, and four pieces. The guided member 26 is provided.

  The lower table 24 has a rectangular plate shape. The lower table 24 is supported by the base 6 through a ball bearing (not shown) so as to be movable in the front-rear direction, the left-right direction, and the direction around the vertical axis.

  The middle table 23 has a rectangular plate shape. The middle table 23 is disposed above the lower table 24. The middle table 23 is guided by the guide rod 230 and can be moved in the vertical direction by a cam mechanism (not shown). Further, the middle table 23 can move independently of the lower table 24.

  The upper table 22 has a rectangular plate shape. The upper table 22 is disposed above the middle table 23. The upper table 22 is supported by the guide rod 230. The upper table 22 can be moved in the vertical direction by a motor (not shown). Further, the upper table 22 is movable independently of the middle table 23. A plurality of backup pins 220 are mounted on the upper surface of the upper table 22.

  The pair of front and rear edge clamps 21 are arranged opposite to each other in the front-rear direction. That is, the pair of front and rear edge clamps 21 project upward from the vicinity of both front and rear edges of the upper surface of the lower table 24. The upper end of the front edge clamp 21 is bent backward. The upper end of the rear edge clamp 21 is bent forward. Each of the pair of edge clamps 21 is movable in the front-rear direction. That is, the interval between the pair of edge clamps 21 can be adjusted.

  The pair of front and rear side clamps 20 are disposed to face each other in the front-rear direction. That is, the pair of front and rear side clamps 20 project upward from the vicinity of both front and rear edges of the upper surface of the middle table 23. The upper end of the front side clamp 20 is bent backward. The upper end of the rear side clamp 20 is bent forward. The rear side clamp 20 is movable in the front-rear direction. That is, the interval between the pair of side clamps 20 can be adjusted.

  The pair of front and rear belt conveyors 25 are arranged to face each other in the front-rear direction. The front belt conveyor 25 is disposed near the upper edge of the rear surface of the front side clamp 20. The front belt conveyor 25 extends in the left-right direction. The rear belt conveyor 25 is disposed in the vicinity of the upper front edge of the rear side clamp 20. The rear belt conveyor 25 extends in the left-right direction. On the pair of front and rear belt conveyors 25, a rectangular circuit board B is placed in a bridging manner.

  The four guided members 26 have a rectangular plate shape. The four guided members 26 protrude downward from near the four corners of the lower surface of the lower table 24. Near the left lower end of the left pair of guided members 26, small-diameter columnar guided portions 260 are projected. In the vicinity of the lower right end of the pair of guided members 26 on the right side, small-diameter columnar guided portions 260 are provided so as to project.

(Ball screw device 4)
The ball screw device 4 includes ball screw portions 4F and 4R. The ball screw portion 4F is disposed near the front edge of the upper surface of the base 6. The ball screw portion 4R is disposed near the rear edge of the upper surface of the base 6. The ball screw portion 4F and the ball screw portion 4R are arranged to face each other in the front-rear direction.

  The front ball screw portion 4F will be described. The ball screw portion 4F includes a shaft portion 40, a nut portion 41, a pair of left and right connecting portions 42, and a pair of left and right guide portions 43. The shaft portion 40 has a round bar shape. The shaft portion 40 protrudes upward from the substantially center of the front edge of the upper surface of the base body 6. A spiral groove (not shown) is formed on the outer peripheral surface of the shaft portion 40. The shaft portion 40 can rotate around the axis by a driving force of a motor (not shown). The pair of left and right guide portions 43 have a round bar shape. The pair of left and right guide portions 43 project upward from the vicinity of both left and right front edges of the upper surface of the base body 6. The pair of left and right guide portions 43 are disposed on both the left and right sides of the shaft portion 40.

  The nut portion 41 has a rectangular plate shape. The nut portion 41 includes a shaft portion insertion hole 410 and a pair of left and right guide portion insertion holes 411. A spiral groove (not shown) is formed on the inner peripheral surface of the shaft portion insertion hole 410. The shaft portion 40 penetrates the shaft portion insertion hole 410 in the vertical direction. The groove portion on the outer peripheral surface of the shaft portion 40 and the groove portion on the inner peripheral surface of the shaft portion insertion hole 410 are engaged via a large number of balls (not shown). The pair of left and right guide portions 43 penetrates the pair of left and right guide portion insertion holes 411 in the vertical direction. The pair of left and right connecting portions 42 protrudes from the rear surface of the nut portion 41. Each of the pair of left and right connecting portions 42 includes a protruding portion (not shown) that can protrude rearward.

  The configuration of the rear ball screw portion 4R is the same as the configuration of the front ball screw portion 4F described above. Further, the rear ball screw portion 4R and the front ball screw portion 4F are arranged substantially symmetrically with the substrate support member 2 interposed therebetween. Therefore, description of the rear ball screw portion 4R is omitted here.

(Mask support member 3, squeegee member 7)
The mask support member 3 is disposed above the substrate support member 2. The mask support member 3 includes a pair of front and rear frame support portions 302. The pair of front and rear frame support portions 302 face each other in the front-rear direction. Each of the pair of front and rear frame support portions 302 has a thin plate shape extending in the left-right direction. The front frame support portion 302 is fixed to the rear surface of the front nut portion 41. The rear frame support portion 302 is fixed to the front surface of the rear nut portion 41. The frame 300 and the screen mask 301 are supported by the mask support member 3. The frame 300 has a rectangular frame shape. The frame 300 is placed between the pair of front and rear frame support portions 302 in a bridging manner. The screen mask 301 has a rectangular thin plate shape. The screen mask 301 is stretched on the frame 300. A substrate-corresponding portion (not shown) is disposed at a substantially central portion of the screen mask 301. The board corresponding part has the same shape as the circuit board B. A large number of printing openings (not shown) are opened in the substrate corresponding part. The printing openings are opened corresponding to the solder printing scheduled positions of the circuit board B. The solder is disposed on the upper surface of the screen mask 301.

  The squeegee member 7 is disposed above the mask support member 3. The squeegee member 7 includes a pair of front and rear squeegee cylinder devices 70, a pair of front and rear squeegees 71, and a pair of left and right guide members 72. The pair of left and right guide members 72 are opposed in the left-right direction. Each of the pair of left and right guide members 72 has a prismatic shape extending in the front-rear direction. Each of the pair of left and right guide members 72 is installed between the pair of front and rear nut portions 41. The pair of front and rear squeegee cylinder devices 70 are engaged with a pair of left and right guide members 72 so as to be slidable in the front-rear direction. The pair of front and rear squeegees 71 are disposed below the pair of front and rear squeegee cylinder devices 70. The pair of front and rear squeegees 71 can move in the vertical direction. The pair of front and rear squeegees 71 can contact the upper surface of the screen mask 301. During solder printing, the pair of front and rear squeegees 71 are driven alternately. The front squeegee 71 pushes the solder into the printing opening of the screen mask 301 while moving from the front toward the rear. The rear squeegee 71 pushes the solder into the printing opening of the screen mask 301 while moving from the rear toward the front.

[Solder printing method]
Next, a solder printing method by the screen printer 1 of the present embodiment will be described. The solder printing method includes a substrate fixing step, an imaging step, a plate aligning step, a transfer step, a fixing step, and a plate separating step.

(Board fixing process)
FIG. 3 shows a right side view in the substrate fixing process of the screen printing machine of the present embodiment. As shown in FIG. 3, in the board fixing step, the upper table 22 and the middle table 23 are raised, and the circuit board B is lifted from the pair of belt conveyors 25 by the backup pins 220. The top surface of the circuit board B, the top surface of the pair of side clamps 20, and the top surface of the pair of edge clamps 21 are at a high level so that the circuit substrate B is sandwiched by the pair of side clamps 20 from the front-rear direction. .

(Imaging process)
FIG. 4 shows a schematic right side view in the imaging process of the screen printing machine of the present embodiment. As shown in FIG. 4, in the imaging process, first, the camera 90 is inserted between the circuit board B and the screen mask 301. Subsequently, the mark (not shown) of the screen mask 301 above the camera 90 and the mark (not shown) of the circuit board B below the camera 90 are imaged. Then, based on the imaging data, the lower table 24 is driven so that the circuit board B and the board corresponding portion of the screen mask 301 face each other in the vertical direction. Thereafter, the camera 90 is withdrawn from between the circuit board B and the screen mask 301.

(Plate matching process)
FIG. 5 shows a schematic right side view in the plate aligning step of the screen printing machine of the present embodiment. As shown in FIG. 5, in the plate aligning step, the pair of front and rear shaft portions of the ball screw device 4 are rotated around the axis. That is, the pair of front and rear nut portions 41 are lowered along the total of four guide portions 43. A mask support member 3 and a squeegee member 7 are installed between the pair of front and rear nut portions 41. For this reason, when the pair of front and rear nut portions 41 are lowered, the mask support member 3 is also lowered. As the mask support member 3 is lowered, the lower surface of the screen mask 301 is brought into close contact with the upper surface of the circuit board B.

(Transfer process)
FIG. 6 shows a schematic right side view in the first stage of the transfer process of the screen printing machine of the present embodiment. As shown in FIG. 6, in the first stage of the transfer process, the protruding portion 420 is protruded from the connecting portion 42. That is, the lower table 24 is sandwiched from the front-rear direction by the pair of front protrusions 420 and the pair of rear protrusions 420. And the nut part 41 and the board | substrate support member 2 are connected via the connection part 42. FIG.

  FIG. 7 shows a schematic right side view in the second stage of the transfer process of the screen printing machine of the present embodiment. As shown in FIG. 7, in the second stage of the transfer process, the pair of front and rear shaft portions of the ball screw device 4 are rotated around the axis. That is, the pair of front and rear nut portions 41 are raised along a total of four guide portions 43. A mask support member 3 and a squeegee member 7 are installed between the pair of front and rear nut portions 41. In addition, the pair of front and rear nut portions 41 are coupled to the substrate support member 2 via the coupling portion 42. For this reason, when the pair of front and rear nut portions 41 are raised, the mask support member 3 and the substrate support member 2 are integrally raised in a state where the adhesion between the screen mask 301 and the circuit board B is ensured. At this time, the four guided portions 260 of the substrate support member 2 rise along the four guide portions 50 of the guide member 5 by the vertical length of the guide portion 50.

  FIG. 8 shows a schematic right side view in the third stage of the transfer process of the screen printing machine of the present embodiment. As shown in FIG. 8, in the third stage of the transfer process, first, the squeegee 71 is lowered from the squeegee cylinder device 70, and the squeegee 71 is brought into contact with the upper surface of the screen mask 301. Next, in this state, the squeegee cylinder device 70 is moved in the front-rear direction along the guide member 72. At this time, the squeegee 71 pushes the solder on the upper surface of the screen mask 301 into the printing opening. The pushed solder adheres to the solder printing scheduled position on the upper surface of the circuit board B.

  FIG. 9 shows a schematic right side view in the fourth stage of the transfer process of the screen printing machine of the present embodiment. As shown in FIG. 9, in the fourth stage of the transfer process, the squeegee 71 is separated upward from the upper surface of the screen mask 301.

(Fixing process)
FIG. 10 shows a schematic right side view in the fixing process of the screen printing machine of the present embodiment. As shown in FIG. 10, in the fixing step, the pair of front and rear shaft portions of the ball screw device 4 are rotated around the axis. That is, the pair of front and rear nut portions 41 are lowered along the total of four guide portions 43. A mask support member 3 and a squeegee member 7 are installed between the pair of front and rear nut portions 41. In addition, the pair of front and rear nut portions 41 are coupled to the substrate support member 2 via the coupling portion 42. Therefore, when the pair of front and rear nut portions 41 are lowered, the mask support member 3 and the substrate support member 2 are integrally lowered in a state where the adhesion between the screen mask 301 and the circuit board B is ensured. At this time, the four guided portions 260 of the substrate support member 2 are lowered along the four guide portions 50 of the guide member 5 by the vertical length of the guide portion 50.

  Here, the rotation speed of the shaft portion in this step is set so as to be slow at the beginning, then gradually increase, and finally stop suddenly. For this reason, the screen mask 301 and the circuit board B first descend slowly, then gradually increase the descending speed, and finally suddenly stop from the maximum speed. When the screen mask 301 and the circuit board B are suddenly stopped, the solder in the printing opening is pressed against the upper surface of the circuit board B by the inertial force at the time of sudden stop.

(Release process)
FIG. 11 shows a schematic right side view in the plate separating process of the screen printing machine of the present embodiment. As shown in FIG. 11, in the plate separating step, first, the lower table 24 is released from the four projecting portions 420 of the connecting portion 42. That is, the connection between the pair of front and rear nut portions 41 and the substrate support member 2 is blocked. Next, the pair of front and rear nut portions 41, the mask support member 3, and the squeegee member 7 are raised by the ball screw device 4. In addition, the circuit board B is released from the pair of side clamps 20. Further, the upper table 22 and the middle table 23 are lowered, and the circuit board B is placed on the pair of belt conveyors 25 in a bridging manner. That is, the screen printer 1 is returned to the state shown in FIG.

[Function and effect]
Next, the effect of the screen printer 1 of this embodiment is demonstrated. The screen printing machine 1 according to this embodiment includes a ball screw device 4. The ball screw device 4 applies an inertial force to the circuit board B and the screen mask 301 by applying a deceleration from above to below. The solder after printing is pressed against the circuit board B by the inertial force. That is, the solder is fixed to the circuit board B. According to the screen printer 1 of the present embodiment, the transferability of solder to the circuit board B can be improved regardless of the size of the electronic component.

  Further, even when a minute gap is interposed between the circuit board B and the screen mask 301, the direction in which the inertial force acts (up and down direction), the direction in which the gap extends (horizontal direction), Are substantially orthogonal. For this reason, it is difficult for the solder to leak from the gap. Therefore, the transfer shape of the solder with respect to the circuit board B is hardly disturbed.

  Further, according to the screen printing machine 1 of the present embodiment, the circuit board B and the screen mask 301 can be relatively separated and brought into contact with each other by the ball screw device 4. For this reason, in the imaging step, the camera 90 can be interposed between the circuit board B and the screen mask 301 as shown in FIG. Further, in the plate separation step, as shown in FIGS. 11 and 2, the circuit board B and the screen mask 301 can be separated. On the other hand, in the fixing process, an inertial force can be applied integrally to the circuit board B and the screen mask 301 as shown in FIG.

  Further, according to the screen printing machine 1 of the present embodiment, the operation direction of the substrate support member 2 can be regulated by the guided portion 260 and the guide portion 50. For this reason, the direction in which the inertial force can be regulated. Further, by adjusting the sliding distance between the guided portion 260 and the guide portion 50 (the vertical length of the guide portion 50), the movement distance (stroke) of the circuit board B and the screen mask 301 when applying an inertial force. ) Can be adjusted. That is, the speeds of the circuit board B and the screen mask 301 can be adjusted.

  Further, according to the screen printing machine 1 of the present embodiment, the circuit board B is adjusted by adjusting the inclination and pitch of the groove portion on the outer peripheral surface of the shaft portion 40 and the inclination and pitch of the groove portion on the inner peripheral surface of the shaft portion insertion hole 410. In addition, the speed of the screen mask 301 can be adjusted. In addition, the speed of the circuit board B and the screen mask 301 can be adjusted by adjusting the rotational speed of the shaft portion 40.

<Second embodiment>
[Configuration of screen printer]
First, the configuration of the screen printing machine of this embodiment will be described. FIG. 12 is a perspective view of the screen printing machine of this embodiment. FIG. 13 shows a right side view of the upper part of the screen printing machine. In addition, about the site | part corresponding to FIG. 1, FIG. 2, it shows with the same code | symbol.

  As shown in FIGS. 12 and 13, the screen printing machine 1 of the present embodiment includes a substrate support member 2, a mask support member 3, a biaxial ball screw device 8, a base 6, a squeegee member 7, and left and right A pair of frames 9 and an imaging device 91 are provided.

(Base 6 and frame 9)
The substrate 6 is arranged on the floor of the factory. The base 6 has a rectangular parallelepiped box shape.

  Each of the pair of left and right frames 9 has a C-shaped frame shape that opens downward. The pair of left and right frames 9 project upward from the vicinity of both left and right edges of the upper surface of the base 6. The pair of left and right frames 9 are opposed to each other in the left-right direction.

(Biaxial ball screw device 8)
FIG. 14 is an enlarged perspective view of the vicinity of the substrate support member of the screen printing machine according to the present embodiment. FIG. 15 is an enlarged perspective view of the vicinity of the mask support member and the squeegee member of the screen printing machine according to the present embodiment.

  As shown in FIGS. 12 to 15, the biaxial ball screw device 8 includes four biaxial ball screw portions 8Fl, 8Fr, 8Rl, 8Rr, three first nut portion timing belts 80, and a first nut portion. Motors (not shown), three second nut portion timing belts 81, and second nut portion motors 82 are provided.

  The biaxial ball screw portion 8 </ b> Fl is disposed near the left front corner of the upper surface of the base body 6. The biaxial ball screw portion 8Fr is disposed near the right front corner of the upper surface of the base 6. The biaxial ball screw portion 8Rl is disposed near the left rear corner of the upper surface of the base 6. The biaxial ball screw portion 8Rr is disposed near the right rear corner of the upper surface of the base 6.

  The right front biaxial ball screw portion 8Fr will be described. The biaxial ball screw portion 8Fr includes a shaft portion 83, a first nut portion 84, a second nut portion 85, a first nut portion pulley 86, and a second nut portion pulley 87.

  The shaft portion 83 has a round bar shape. The shaft portion 83 protrudes upward from the upper surface of the base body 6. A spiral groove 830 is formed on the outer peripheral surface of the shaft portion 83. The lower end of the shaft portion 83 is connected to the first nut portion motor. The shaft portion 83 can rotate around the axis by the driving force of the first nut portion motor.

  The first nut portion 84 has a cylindrical shape. The first nut portion 84 is mounted on the shaft portion 83. A spiral groove (not shown) is formed on the inner peripheral surface of the first nut portion 84. The groove portion 830 on the outer peripheral surface of the shaft portion 83 and the groove portion on the inner peripheral surface of the first nut portion 84 are engaged via a large number of balls (not shown). For this reason, the 1st nut part 84 is movable to an up-down direction, when the shaft part 83 rotates around an axis | shaft.

  The first nut portion pulley 86 has a cylindrical shape. The first nut pulley 86 is mounted on the shaft 83. The first nut portion pulley 86 is fixed to the outer peripheral surface of the shaft portion 83. The first nut portion pulley 86 is disposed below the first nut portion 84.

  The second nut portion 85 has a cylindrical shape. The second nut portion 85 is mounted on the shaft portion 83. The second nut portion 85 is disposed above the first nut portion 84. FIG. 16 is an enlarged cross-sectional view in the frame XVI of FIG. As shown in FIG. 16, the second nut portion 85 includes an inner cylinder portion 850, an outer cylinder portion 851, and a bearing portion 852. The inner cylinder part 850 has a long-axis cylindrical shape. A spiral groove (not shown) is formed on the inner peripheral surface of the inner cylinder portion 850. The groove portion 830 on the outer peripheral surface of the shaft portion 83 and the groove portion on the inner peripheral surface of the inner cylinder portion 850 are engaged via a large number of balls (not shown). For this reason, the inner cylinder part 850 is movable in the up-down direction when the shaft part 83 rotates around the axis. In addition, the inner cylinder portion 850 can move in the vertical direction by rotating around the axis of the shaft portion 83 by a driving force of a second nut portion motor 82 described later. The outer cylinder portion 851 has a short-axis cylindrical shape. The outer cylinder portion 851 is disposed on the radially outer side of the inner cylinder portion 850. The bearing portion 852 is interposed between the inner cylinder portion 850 and the outer cylinder portion 851. Through the bearing portion 852, the inner cylinder portion 850 and the outer cylinder portion 851 can rotate independently of each other. In addition, the inner cylinder portion 850 and the outer cylinder portion 851 can be moved in the vertical direction integrally.

  The second nut portion pulley 87 has a cylindrical shape. The second nut portion pulley 87 is mounted around the inner cylinder portion 850 of the second nut portion 85. The second nut portion pulley 87 is fixed to the outer peripheral surface of the inner cylinder portion 850. The second nut portion pulley 87 is disposed above the outer cylinder portion 851 of the second nut portion 85.

  The configuration of the left front biaxial ball screw portion 8Fl is the same as the configuration of the right front biaxial ball screw portion 8Fr described above. Accordingly, the description of the left front ball screw portion 8Fl is omitted here.

  The biaxial ball screw portion 8Rr on the right rear will be described. The difference between the configuration of the biaxial ball screw portion 8Rr and the configuration of the above-described right front biaxial ball screw portion 8Fr is that the first nut portion left and right connecting pulley 88 is located above the first nut portion pulley 86. It is a point that is arranged. In addition, the second nut portion left and right connecting pulley 89 is disposed above the second nut portion pulley 87. Therefore, only the differences will be described here.

  As shown in FIG. 14, the first nut portion left and right connecting pulley 88 has a cylindrical shape. The first nut portion left and right connecting pulley 88 is mounted around the shaft portion 83. The first nut portion left and right connecting pulley 88 is fixed to the outer peripheral surface of the shaft portion 83.

  As shown in FIG. 15, the second nut portion left and right connecting pulley 89 has a cylindrical shape. FIG. 17 is an enlarged cross-sectional view in the frame XVII in FIG. As shown in FIG. 17, the second nut portion right and left connecting pulley 89 is mounted on the shaft portion 83 so as to be relatively rotatable. The second nut portion left and right connecting pulley 89 is fixed to the upper surface of the second nut portion pulley 87.

  The configuration of the left rear biaxial ball screw portion 8Rl is the same as the configuration of the right rear biaxial ball screw portion 8Rr described above. Accordingly, the description of the left rear ball screw portion 8Rl is omitted here.

  As shown in FIG. 14, the first nut portion timing belt 80 is made of rubber and has an annular shape. A total of three first nut portion timing belts 80 are arranged. Among these, the first first nut portion timing belt 80 is stretched between a pair of front and rear first nut portion pulleys 86 on the right side. The second first nut portion timing belt 80 is stretched between a pair of front and rear first nut portion pulleys 86 on the left side. The third first nut portion timing belt 80 is stretched between a pair of rear left and right first nut portion left and right connecting pulleys 88. That is, the three first nut portion timing belts 80 are arranged in a U-shape opening forward.

  As shown in FIG. 15, the second nut portion timing belt 81 is made of rubber and has an annular shape. A total of three second nut portion timing belts 81 are arranged. Of these, the first second nut portion timing belt 81 is stretched between a pair of front and rear second nut portion pulleys 87. The second second nut portion timing belt 81 is stretched between a pair of front and rear pulleys 87 for the second nut portion. The third second nut portion timing belt 81 is stretched between a pair of rear left and right second nut portion left and right connecting pulleys 89. That is, the three second nut portion timing belts 81 are arranged in a U-shape opening forward.

  As shown in FIG. 15, the second nut portion motor 82 is disposed substantially at the center of the rear edge of the mask support member 3 described later. Of the three second nut timing belts 81, the rear second nut timing belt 81 is also wound around the rotation shaft 820 of the second nut motor 82.

(Substrate support member 2)
As shown in FIGS. 12 to 14, the substrate support member 2 is disposed above the base 6. The substrate support member 2 mainly includes a pair of front and rear fixed wall portions 27, a movable wall portion 28, an upper table 22, an intermediate table 23, a lower table 24, a pair of front and rear belt conveyors 25, and a ball screw portion. 29.

  The lower table 24 has a rectangular plate shape. Four first nut fixing holes 240 are formed in the four corners of the lower table 24. First nut portions 84 are fixed to the inner peripheral surfaces of the four first nut portion fixing holes 240, respectively.

  The pair of front and rear fixed wall portions 27 are erected on the upper surface of the lower table 24. The front fixed wall 27 has a thin plate shape that is long in the left-right direction. The front fixed wall portion 27 is disposed at the front portion of the lower table 24. The rear fixed wall 27 has a thin plate shape that is long in the left-right direction. The rear fixed wall portion 27 is disposed along the rear edge of the lower table 24.

  The ball screw portion 29 includes a pair of left and right shaft portions 290 and a pair of left and right nut portions 291. The shaft portion 290 is constructed between the pair of front and rear fixed wall portions 27. The nut portion 291 is engaged with the shaft portion 290 via a large number of balls (not shown).

  The movable wall portion 28 is interposed between the pair of front and rear fixed wall portions 27. A pair of nut portions 291 of the ball screw portion 29 are fixed near the left and right edges of the movable wall portion 28. The movable wall portion 28 can be moved in the front-rear direction by a ball screw portion 29. A notch 280 opening downward is formed at the lower edge of the movable wall portion 28.

  The pair of front and rear belt conveyors 25 are arranged to face each other in the front-rear direction. The pair of front and rear belt conveyors 25 extend in the left-right direction. The front belt conveyor 25 is disposed on the rear surface of the front fixed wall portion 27. The rear belt conveyor 25 is disposed in front of the movable wall portion 28. On the pair of front and rear belt conveyors 25, a rectangular circuit board B is placed in a bridging manner. By moving the movable wall portion 28, the distance between the pair of front and rear belt conveyors 25 can be adjusted.

  The middle table 23 has a rectangular plate shape. The middle table 23 is disposed above the lower table 24. The middle table 23 is movable in the vertical direction. Further, the middle table 23 can move independently of the lower table 24. The movement allowance of the middle table 23 is secured by the notch 280.

  The upper table 22 has a rectangular plate shape. The upper table 22 is disposed above the middle table 23. The upper table 22 is movable in the vertical direction. Further, the upper table 22 is movable independently of the middle table 23. The movement allowance of the upper table 22 is secured by the notch 280. A plurality of backup blocks 221 are arranged on the upper surface of the upper table 22.

(Mask support member 3)
As shown in FIGS. 12, 13, and 15 to 17, the mask support member 3 includes a mask table 31 and a pair of left and right frame support portions 302.

  The mask table 31 has a U-shaped plate opening forward. Four second nut fixing holes 310 are formed in the four corners of the mask table 31. The outer cylindrical portions 851 of the second nut portions 85 are fixed to the inner peripheral surfaces of the four second nut portion fixing holes 310, respectively. The pair of left and right frame support portions 302 are opposed in the left-right direction. The pair of left and right frame support portions 302 extend in the front-rear direction. The pair of left and right frame support portions 302 are fixed to the lower surface of the mask table 31 so as to be separated in the left-right direction. The left frame support portion 302 has an L shape when viewed from the front. The right frame support portion 302 has an inverted L shape when viewed from the front.

  The frame 300 and the screen mask 301 are supported by the mask support member 3. The frame 300 has a rectangular frame shape. The frame 300 is placed between the pair of left and right frame support portions 302 in a bridging manner. The screen mask 301 has a rectangular thin plate shape. The screen mask 301 is stretched on the frame 300. A substrate-corresponding portion (not shown) is disposed at a substantially central portion of the screen mask 301. The board corresponding part has the same shape as the circuit board B. A large number of printing openings (not shown) are opened in the substrate corresponding part. The printing openings are opened corresponding to the solder printing scheduled positions of the circuit board B. The solder is disposed on the upper surface of the screen mask 301.

(Squeegee member 7)
The squeegee member 7 is disposed above the mask support member 3. The squeegee member 7 includes an erection member 73, a pair of front and rear squeegees 71, and a pair of left and right guide members 72. The pair of left and right guide members 72 are opposed in the left-right direction. Each of the pair of left and right guide members 72 has a stepped prism shape extending in the front-rear direction. The pair of left and right guide members 72 are fixed to the upper surface of the mask table 31 so as to be separated in the left-right direction.

  The erection member 73 has a prismatic shape that is long in the left-right direction. A pair of guided portions 730 are recessed in the left and right ends of the lower surface of the erection member 73. The pair of left and right guided portions 730 are engaged with the pair of left and right guide members 72 so as to be slidable in the front-rear direction.

  The pair of front and rear squeegees 71 are disposed below the erection member 73. The pair of front and rear squeegees 71 can move in the vertical direction. The pair of front and rear squeegees 71 can contact the upper surface of the screen mask 301. During solder printing, the pair of front and rear squeegees 71 are driven alternately. The front squeegee 71 pushes the solder into the printing opening of the screen mask 301 while moving from the front toward the rear. The rear squeegee 71 pushes the solder into the printing opening of the screen mask 301 while moving from the rear toward the front.

(Imaging device 91)
As illustrated in FIGS. 12 and 13, the imaging device 91 includes a camera 910 and a pair of left and right guide portions 911. The pair of left and right guide portions 911 face each other in the left-right direction. The pair of left and right guide portions 911 have a prismatic shape that is long in the front-rear direction. The left guide portion 911 is provided between the front edge and the rear edge of the left frame 9. The right guide portion 911 is constructed between the front edge and the rear edge of the right frame 9. The camera 910 can slide in the front-rear direction with respect to the pair of left and right guide portions 911.

[Motion of screen printer]
Next, the movement of the screen printing machine 1 according to the present embodiment will be described. First, the case where the board | substrate support member 2 is moved to an up-down direction is demonstrated. When moving the board | substrate support member 2, the motor for 1st nut parts is driven. As described above, the shaft portion 83 of the right front biaxial ball screw portion 8Fr shown in FIG. 14 is connected to the first nut portion motor. The driving force of the first nut portion motor is changed from the right front shaft portion 83 to the right front first nut portion pulley 86 → the right first nut portion timing belt 80 → the right rear first nut portion pulley 86 → Right rear first nut portion right and left connecting pulley 88 → Rear first nut portion timing belt 80 → Left rear first nut portion left and right connecting pulley 88 → Left rear first nut portion pulley 86 → Left side The first nut part timing belt 80 is transmitted to the right rear, left rear, and left front shaft part 83 through a transmission path of the first nut part pulley 86 on the left front side. For this reason, the four first nut portions 84, that is, the substrate support members 2, move in the vertical direction in synchronization with the rotation of the four shaft portions 83 around the axes. Thus, the board | substrate support member 2 can be moved to an up-down direction by driving the motor for 1st nut parts.

  Next, a case where the mask support member 3 and the squeegee member 7 are moved will be described. When the mask support member 3 and the squeegee member 7 are moved, at least one of the first nut motor and the second nut motor 82 shown in FIG. 15 is driven.

  The driving force of the first nut portion motor is transmitted to each shaft portion 83 through the transmission path described above. Here, as shown in FIGS. 16 and 17, in addition to the first nut portion 84, the inner cylinder portion 850 of the second nut portion 85 is also mounted around the four shaft portions 83. For this reason, the four second nut portions 85, that is, the mask support member 3 and the squeegee member 7 move in the vertical direction in synchronization with the rotation of the four shaft portions 83 around the axes. Thus, the mask support member 3 and the squeegee member 7 can be moved in the vertical direction by driving the first nut portion motor.

  Further, the driving force of the second nut portion motor 82 is shown in FIG. 15 from the rotary shaft 820 to the rear second nut portion timing belt 81 → the pair of left and right second nut portion left and right connecting pulleys 89 → rearward. A pair of left and right second nut portion pulleys 87 → second nut portion timing belt 81 on both left and right sides → a pair of front left and right second nut portion pulleys 87, a rear left and right, front left and right second nut portions. 85 is transmitted to the inner cylinder portion 850 (see FIGS. 16 and 17). For this reason, the inner cylinder portions 850 of the four second nut portions 85 move in the vertical direction in synchronization with each other while rotating around the axis of the shaft portion 83. Accordingly, the outer cylindrical portions 851 of the four second nut portions 85, that is, the mask support member 3 and the squeegee member 7 move in the vertical direction in synchronization. In this way, by driving the second nut portion motor 82, the mask support member 3 and the squeegee member 7 can be moved in the vertical direction.

  As described above, by driving at least one of the first nut portion motor and the second nut portion motor 82, by changing the rotational speed of each motor, or by rotating the rotation direction of each motor forward and backward. By controlling, the substrate support member 2, the mask support member 3, and the squeegee member 7 can be moved independently or integrally.

[Solder printing method]
Next, a solder printing method by the screen printer 1 of the present embodiment will be described. The solder printing method includes a substrate fixing step, an imaging step, a plate aligning step, a transfer step, a fixing step, and a plate separating step.

(Board fixing process)
FIG. 18 shows a schematic right side view in the substrate fixing process of the upper part of the screen printing machine of the present embodiment. For convenience of explanation, the squeegee 71, the frame 300, and the screen mask 301 are shown in a transparent manner.

  As shown in FIG. 18, in the board fixing step, the upper table 22 and the middle table 23 are raised, and the circuit board B is lifted from the pair of belt conveyors 25 by the backup block 221. The circuit board B is configured so that the upper surface of the circuit board B, the upper surface of the front fixed wall portion 27, and the upper surface of the movable wall portion 28 are substantially flush with each other. B is sandwiched from the front-rear direction.

(Imaging process)
FIG. 19 shows a schematic right side view in the imaging process of the upper part of the screen printing machine of the present embodiment. As shown in FIG. 19, in the imaging process, first, the first nut motor is driven to rotate the shaft 83 of the biaxial ball screw device 8 around the axis. And the 1st nut part 84, ie, the board | substrate support member 2, is moved below. At the same time, the second nut motor is driven to rotate the second nut 85 of the biaxial ball screw device 8 around the shaft 83. Then, the second nut portion 85, that is, the mask support member 3 and the squeegee member 7 are moved upward. In this way, a predetermined gap is ensured between the circuit board B and the screen mask 301.

  Next, the camera 910 is inserted between the circuit board B and the screen mask 301 along the guide portion 911. Subsequently, the mark (not shown) of the screen mask 301 above the camera 910 and the mark (not shown) of the circuit board B below the camera 910 are imaged. Then, based on the imaging data, alignment is performed so that the circuit board B and the board corresponding part of the screen mask 301 face each other in the vertical direction. Thereafter, the camera 910 is withdrawn from between the circuit board B and the screen mask 301 along the guide portion 911.

(Plate matching process)
FIG. 20 shows a schematic right side view in the plate aligning step of the upper part of the screen printing machine of the present embodiment. As shown in FIG. 20, in the plate aligning step, the second nut motor is driven to rotate the second nut 85 of the biaxial ball screw device 8 around the shaft 83. Then, the second nut portion 85, that is, the mask support member 3 and the squeegee member 7 are moved downward. As the mask support member 3 is lowered, the lower surface of the screen mask 301 is brought into close contact with the upper surface of the circuit board B.

(Transfer process)
FIG. 21 shows a schematic right side view in the transfer process of the upper part of the screen printer of this embodiment. As shown in FIG. 21, in the transfer process, first, the squeegee 71 is lowered from the erection member 73, and the squeegee 71 is brought into contact with the upper surface of the screen mask 301. Next, in this state, the erection member 73 is moved in the front-rear direction along the guide member 72. At this time, the squeegee 71 pushes the solder on the upper surface of the screen mask 301 into the printing opening. The pushed solder adheres to the solder printing scheduled position on the upper surface of the circuit board B. Thereafter, the squeegee 71 is separated upward from the upper surface of the screen mask 301.

(Fixing process)
FIG. 22 shows a schematic right side view in the fixing process of the upper part of the screen printer of this embodiment. As shown in FIG. 22, in the fixing process, the first nut motor is driven to rotate the shaft 83 of the biaxial ball screw device 8 about the axis. Then, the first nut portion 84 and the second nut portion 85 are simultaneously moved upward. That is, the substrate support member 2, the mask support member 3, and the squeegee member 7 are simultaneously moved upward.

  Here, the rotational speed of the shaft portion in this step is set so that it is initially fast, then gradually slows, and finally slowly stops. For this reason, the screen mask 301 and the circuit board B first rise rapidly, then gradually decrease in the rising speed, and finally stop slowly. When the screen mask 301 and the circuit board B rapidly rise, the solder in the printing opening is pressed against the upper surface of the circuit board B by the inertial force at the time of sudden rise.

(Release process)
In the plate separation process, as shown in FIG. 22, first, the first nut motor is driven to rotate the shaft 83 of the biaxial ball screw device 8 about the axis. And the 1st nut part 84, ie, the board | substrate support member 2, is moved below. At the same time, the second nut motor is driven to rotate the second nut 85 of the biaxial ball screw device 8 around the shaft 83. Then, the second nut portion 85, that is, the mask support member 3 and the squeegee member 7 are moved downward. In this way, the screen printer 1 is returned to the state shown in FIG.

  Subsequently, the circuit board B is released from the front fixed wall portion 27 and the movable wall portion 28. Further, the upper table 22 and the middle table 23 are lowered, and the circuit board B is placed on the pair of belt conveyors 25 in a bridging manner. That is, the screen printer 1 is returned to the state shown in FIG.

[Function and effect]
Next, the effect of the screen printer 1 of this embodiment is demonstrated. The screen printing machine 1 according to this embodiment includes a biaxial ball screw device 8. The biaxial ball screw device 8 applies an inertial force to the circuit board B and the screen mask 301 by applying acceleration from below to above. The solder after printing is pressed against the circuit board B by the inertial force. That is, the solder is fixed to the circuit board B. According to the screen printer 1 of the present embodiment, the transferability of solder to the circuit board B can be improved regardless of the size of the electronic component.

  Further, even when a minute gap is interposed between the circuit board B and the screen mask 301, the direction in which the inertial force acts (up and down direction), the direction in which the gap extends (horizontal direction), Are substantially orthogonal. For this reason, it is difficult for the solder to leak from the gap. Therefore, the transfer shape of the solder with respect to the circuit board B is hardly disturbed.

  Further, according to the screen printing machine 1 of the present embodiment, the substrate support member 2 is driven by the first nut portion 84 as shown in FIG. In addition, as shown in FIGS. 15 to 17, the mask support member 3 is driven by the second nut portion 85.

  The first nut portion 84 can move in the vertical direction as the shaft portion 83 rotates. Similar to the first nut portion 84, the second nut portion 85 can move in the vertical direction as the shaft portion 83 rotates. Moreover, the 2nd nut part 85 is movable to an up-down direction, when self rotates. That is, the second nut portion 85 can move in the axial direction of the shaft portion 83 not only when the shaft portion 83 is rotating but also when the shaft portion 83 is stopped. That is, the first nut portion 84 and the second nut portion 85 can move independently of each other.

  For example, the first nut portion 84 and the second nut portion 85 can be moved in the same direction at the same speed. Further, the first nut portion 84 and the second nut portion 85 can be moved in the same direction at different speeds. Further, the first nut portion 84 and the second nut portion 85 can be moved in the opposite directions at the same speed. Further, the first nut portion 84 and the second nut portion 85 can be moved at different speeds in the opposite directions.

  For this reason, the space | interval of the board | substrate support member 2 and the mask support member 3 can be freely adjusted simultaneously or with a predetermined time difference. Accordingly, in the imaging step, as shown in FIG. 19, the substrate support member 2 can be moved downward and the mask support member 3 can be moved simultaneously simultaneously. That is, the space for the camera 910 can be quickly secured as compared with the case where only the substrate support member 2 is movable in the vertical direction. In the plate separation step, as shown in FIGS. 22 and 18, a desired plate separation speed (relative speed between the circuit board B and the screen mask 301) can be ensured. On the other hand, in the fixing step, an inertial force can be applied integrally to the circuit board B and the screen mask 301 as shown in FIG.

  Further, according to the screen printing machine 1 of the present embodiment, the inclination and pitch of the groove portion on the outer peripheral surface of the shaft portion 83, the inclination and pitch of the groove portion on the inner peripheral surface of the first nut portion 84, and the inner cylinder of the second nut portion 85. The speed of the circuit board B and the screen mask 301 can be adjusted by adjusting the inclination and pitch of the groove on the inner peripheral surface of the portion 850. In addition, the speed of the circuit board B and the screen mask 301 can be adjusted by adjusting the rotational speed of the shaft portion 83.

<Others>
The embodiment of the screen printing machine of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  In the first embodiment, an inertial force is applied to the solder by suddenly stopping the circuit board B and the screen mask 301 from the maximum speed state. In the second embodiment, an inertial force is applied to the solder by rapidly starting the circuit board B and the screen mask 301 from the stopped state. However, the method for applying an inertial force to the solder is not particularly limited. An inertial force may be applied to the solder by applying acceleration or deceleration to the circuit board B and the screen mask 301 in stages.

  In addition, inertia force may be applied to the solder by causing the circuit board B and the screen mask 301 to stop suddenly from the maximum speed state using the screen printing machine 1 of the second embodiment. Similarly, an inertial force may be applied to the solder by causing the circuit board B and the screen mask 301 to suddenly start from a stopped state using the screen printer 1 of the first embodiment. That is, the moving direction of the circuit board B and the screen mask 301 and the direction of the inertial force with respect to the solder in the fixing process are not particularly limited.

  In the first embodiment, an inertial force is applied to the solder by the ball screw device 4. In the second embodiment, an inertial force is applied to the solder by the biaxial ball screw device 8. However, for example, an inertial force may be applied to the solder by naturally dropping the circuit board B and the screen mask 301. Further, an inertial force may be applied to the solder by moving the circuit board B and the screen mask 301 with an actuator such as a hydraulic cylinder, an air cylinder, or a solenoid. In addition, an inertial force may be applied to the solder by causing the moving circuit board B and the screen mask 301 to collide with a stopper made of an elastic member such as rubber or urethane. That is, an inertial force may be applied to the solder by impact.

  Moreover, the mechanism in which the protrusion part 420 is made to go in and out with respect to the connection part 42 in said 1st embodiment is not specifically limited. An actuator such as a hydraulic cylinder, an air cylinder, or a solenoid may be used. Further, the moving distance of the circuit board B and the screen mask 301 in the fixing process of the above embodiment is not particularly limited. What is necessary is just to adjust suitably so that a desired inertia force may be acquired.

  Further, the position (height) of plate alignment between the circuit board B and the screen mask 301 is not particularly limited. It may be set in consideration of the transport height of the circuit board B, the position of the circuit board B in the previous process and the next process, and the like.

  Further, the time-speed pattern of the screen mask 301 and the circuit board B in the fixing process is not particularly limited. FIG. 23 shows a schematic diagram of a time-speed pattern that can be employed in the fixing process of the screen printing machine of the present invention. FIG. 23 shows a case where the solder is fixed to the circuit board B by applying a rapid deceleration to the screen mask 301 and the circuit board B.

  As shown in the pattern a of FIG. 23, the screen mask 301 and the circuit board B may be controlled so as to accelerate slowly at first, maintain a maximum speed state halfway, and finally decelerate and stop suddenly. Further, as shown in the pattern b of FIG. 23, the screen mask 301 and the circuit board B may be controlled so as to accelerate slowly at first and then rapidly decelerate and stop immediately after reaching the maximum speed state. Further, as shown in a pattern c in FIG. 23, a pattern (pattern b) of accelerating at first and then rapidly decelerating and stopping immediately after reaching the maximum speed state may be repeated a plurality of times. Of course, the pattern a may be repeated a plurality of times.

  Further, when the solder is fixed to the circuit board B by applying a rapid acceleration to the screen mask 301 and the circuit board B, the time-speed pattern shown in FIG. .

  In addition, the configuration of the above (5) and the screen printing machine 1 of the second embodiment may not be used for the purpose of applying an inertial force integrally to the circuit board B and the screen mask 301. Even if it is not used for the application, the advantage that the substrate support member 2 and the mask support member 3 can be independently driven is the configuration of the above (5), the screen printing of the second embodiment. The machine 1 has. For example, since the imaging process and the like can be performed quickly, the cycle time of circuit board B production can be shortened. Further, in the plate aligning step and the plate separating step, the contact and separation between the circuit board B and the screen mask 301 can be precisely controlled. In the plate matching step, the level of plate matching can be controlled up and down.

1: screen printer, 2: substrate support member, 3: mask support member, 4: ball screw device, 4F: ball screw portion, 4R: ball screw portion, 5: guide member, 6: base, 7: squeegee member, 8: biaxial ball screw device, 8Fl: biaxial ball screw portion, 8Fr: biaxial ball screw portion, 8Rl: biaxial ball screw portion, 8Rr: biaxial ball screw portion, 9: frame.
20: side clamp, 21: edge clamp, 22: upper table, 23: middle table, 24: lower table, 25: belt conveyor, 26: guided member, 27: fixed wall, 28: movable wall, 29: Ball screw part, 31: mask table, 40: shaft part, 41: nut part, 42: connecting part, 43: guide part, 50: guide part, 70: cylinder device for squeegee, 71: squeegee, 72: guide member 73: Construction member, 80: Timing belt for first nut part, 81: Timing belt for second nut part, 82: Motor for second nut part, 83: Shaft part, 84: First nut part, 85: First Two nut parts, 86: Pulley for the first nut part, 87: Pulley for the second nut part, 88: Pulley for connecting the first nut part to the left and right, 89: Left and right connection for the second nut part Use pulley, 90: camera, 91: image pickup device.
220: backup pin, 221: backup block, 230: guide rod, 240: first nut portion fixing hole, 260: guided portion, 280: notch portion, 290: shaft portion, 291: nut portion, 300: frame, 301 : Screen mask, 302: Frame support part, 310: Second nut part fixing hole, 410: Shaft part insertion hole, 411: Guide part insertion hole, 420: Projection part, 730: Guided part, 820: Rotating shaft, 830 : Groove part, 850: inner cylinder part, 851: outer cylinder part, 852: bearing part, 910: camera, 911: guide part.
B: Circuit board.

Claims (6)

  An inertial force is integrally applied to the circuit board after the solder printing and the screen mask before the plate separation that is substantially in contact with the circuit board in the stacking direction of the circuit board and the screen mask, and the solder against the circuit board A screen printer provided with an inertial force generator for improving the transferability of the ink.   2. The screen printing machine according to claim 1, wherein the inertial force generation device applies the inertial force to the circuit board and the screen mask by applying at least one of acceleration and deceleration in a predetermined pattern. Furthermore, a board support member that supports the circuit board, and a mask support member that supports the screen mask so that the screen mask is disposed above the circuit board,
The screen printing machine according to claim 1, wherein the inertial force generation device connects the substrate support member and the mask support member so that the circuit board and the screen mask can be separated from each other. The inertial force generating device includes a shaft portion, a nut portion that is inserted through the shaft portion and rotated around an axis, and is movable in an axial direction of the shaft portion, the nut portion, and the substrate support member And a connecting part capable of connecting one of the mask support members, and a ball screw device,
The other of the substrate support member and the mask support member follows the nut portion,
The ball screw device connects the nut portion and one of the substrate support member and the mask support member via the connecting portion, and moves the nut portion to thereby connect the circuit board and the screen mask. The screen printing machine according to claim 3, wherein an inertial force is applied integrally to the screen printing machine. The substrate support member has a guided portion,
The screen printing machine according to claim 4, further comprising a guide member having a guide portion on which the guided portion slides when an inertial force is integrally applied to the circuit board and the screen mask. The inertial force generator includes a shaft portion, a first nut portion that is movable in an axial direction of the shaft portion when the shaft portion is inserted and the shaft portion rotates around an axis, and the shaft portion is inserted. A second nut that is movable in the axial direction of the shaft portion by rotating about the axis of the shaft portion, and is movable in the axial direction of the shaft portion by rotating itself around the axis of the shaft portion A biaxial ball screw device having a portion,
One of the substrate support member and the mask support member is driven by the first nut portion,
Of the substrate support member and the mask support member, the other follows the second nut portion,
The biaxial ball screw device according to claim 3, wherein at least one of the first nut portion and the second nut portion is moved to apply an inertial force integrally to the circuit board and the screen mask. Screen printing machine.

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