JPH0213474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a screen printing machine that prints adhesive or creamy solder on a predetermined portion of a printed circuit board, and particularly to a screen printing machine that prints adhesive or creamy solder on a predetermined portion of a printed circuit board. This invention relates to a screen printing machine that can perform printing.

2. Description of the Related Art It is widely practiced to construct an electronic circuit by attaching chip-shaped circuit components to a printed circuit board on which a wiring pattern is formed. To do this, adhesive is applied in spots to predetermined areas on the printed circuit board, and the lead wires of the circuit components are soldered to the wiring pattern while the circuit components are temporarily attached to the printed circuit board using the adhesive. However, a screen printing machine is used as one device for applying this adhesive. In addition, creamy solder is applied to the wiring pattern in advance and the lead wires of circuit components are soldered to the wiring pattern using the creamy solder. A screen printing machine is used.

This screen printing machine includes a substrate support stand, a screen support stand disposed above the substrate support stand, and a squeegee movable in a linear direction above the substrate support stand, and the squeegee moves over the screen supported by the screen support stand. By doing so, adhesive or creamy solder is printed on a predetermined portion of the printed circuit board supported on the board support stand.

One of these screen printing machines was published in Japanese Patent Publication No. 57-2596.
It is stated in the No. This is equipped with multiple ropes that move parallel to the top surface of the board support stand, and when the board support stand is in the lowered position, these ropes support and transport the printed circuit board, and the board support When the platform is raised to support the substrate, each rope is accommodated in a groove formed on the top surface of the substrate support. In addition, in order to save the installation space of the screen printing machine,
The direction in which the printed circuit board is transported by the rope is made to match the direction in which the squeegee moves.

Problems to be Solved by the Invention As described above, when a printed circuit board is transported between a board support stand and a screen using a transport device such as a rope, it is difficult to easily position the printed circuit board with respect to the board support stand. In order to do this, it is desirable to provide a pair of guide rails for guiding both side edges of the printed circuit board. Further, in order to be able to supply printed circuit boards having a plurality of different widths, it is desirable to be able to change the distance between the pair of guide rails.

However, if one of the pair of guide rails is a fixed rail and the other is a movable rail that can approach and move away from the fixed rail, the width direction of all printed circuit boards with different widths can be controlled by the central device, the board support stand, It becomes impossible to match the central device of the printing mechanism consisting of a screen, a squeegee, etc., and uneven printing is likely to occur. In screen printing machines, if the center of the printed circuit board is not aligned with the center of the printing mechanism, the thickness (amount of applied adhesive) of the printed adhesive or cream solder tends to be uneven in the width direction of the printed circuit board. be.

A pair of guide rails are both movable rails,
The above problem can be solved if printed circuit boards of different widths can be guided by moving them symmetrically, but if the pair of guide rails are both movable rails, the transfer device Another problem arises in that the structure becomes complicated and the manufacturing cost of the screen printing machine increases.

In view of the above circumstances, the present invention has been developed to enable printed circuit boards with different widths to be supplied with their widthwise centers always aligned with the center of the printing mechanism, without complicating the structure of the conveying device. This was done with the aim of doing so.

Means for Solving the Problems To achieve this, the present invention includes a substrate support, a screen support, and a squeegee, and the squeegee linearly moves over the screen supported by the screen support. In a screen printing machine that prints adhesive, cream solder, etc. on a printed circuit board supported by a board support, the board support, screen support, and squeegee can be moved in a direction perpendicular to the direction of movement of the squeegee. The board transport device is installed on a movable table and carries and/or transports the printed circuit board between the board support stand and the screen support stand in a direction parallel to the direction of movement of the squeegee. of,
a fixed rail that guides one side edge of the printed circuit board;
It is possible to approach and move away from the fixed rail,
It is equipped with a movable rail that guides the other side edge of the printed circuit board, and is capable of transporting printed circuit boards of different widths. A moving device is provided that moves the movable platform in the same direction as the moving direction of the movable rail and by half the distance in conjunction with the movement, so that the substrate support platform and the screen can be moved even if the width of the substrate transfer device is changed. The widthwise centers of the support stand and the squeegee and the substrate transport device are always aligned.

In one embodiment of the present invention, the moving device includes a plurality of rail nuts fixed to the movable rail at a distance in the longitudinal direction of the movable rail and in an attitude perpendicular to the movable rail, and a plurality of rail nuts that are rotatable and axially A rail feed screw fixed to the movable base in a position parallel to the rail nut, a movable base nut fixed to the movable base in a position parallel to the rail nut, and a movable base nut rotatably but immovable in the axial direction. The movable base feed screw screwed into the movable base feed screw, the movable base feed screw, and the rail feed screw, the product of the pitch of the rail feed screw and the number of revolutions is twice the product of the pitch of the movable base feed screw and the number of revolutions. and a rotation transmission mechanism that is coupled so as to

Functions and Effects In the printed circuit board screen printing machine according to the present invention, when the width of the printed circuit board to be printed changes and the movable rail approaches or moves away from the fixed rail accordingly, the moving direction of the movable rail is The movable base is moved in the same direction and by half the distance. Therefore, the printing mechanism such as a squeegee supported by the movable base also moves by half the distance in the same direction as the movable rail, and the center position of the printing mechanism is always the same as the center position of the printed circuit board. They match, and the occurrence of printing unevenness is avoided.

Moreover, since it is only necessary to move one of the pair of guide rails, the structure of the substrate transport device does not become complicated and the manufacturing cost of the screen printing machine does not increase.

In particular, when the moving device includes a rail nut, a rail feed screw, a movable base nut, a movable base feed screw, and a rotation transmission mechanism, the movable rail and the movable base can be interlocked with a device with an extremely simple structure. , a further cost reduction effect can be obtained.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

The printed circuit board screen printing machine shown in FIGS. 1 and 2 includes a printed circuit board positioning and supporting device 1.
0, a screen positioning support device 12, a squeegee device 14, a substrate conveyor 16, and a substrate holding device 17.

The substrate positioning support device 10 includes a substrate support stand 18
The screen positioning support device 12 positions the screen 24 and the screen frame 26 fixed to the periphery thereof on the screen support base 22, and positions and supports the printed circuit board 20 thereon and raises and lowers it a certain distance. This is what we support. The squeegee device 14 moves a squeegee 28 up and down between a lowered position where it contacts the screen 24 and an upper position, and also moves it in a linear direction along the screen 24. The substrate conveyor 16 functions as a substrate conveyance device,
The printed circuit board 20 is guided by a fixed rail 30 and a movable rail 32, and is carried into between the board support stand 18 and the screen 24 by a pair of endlessly wound ropes 33, and carried out from there. It is something. Then, the board holding device 17 holds the printed circuit board 20 placed on the board support stand 18 using a board holding plate (generally a board holding member).
34 to press against the substrate support stand 18.

Of the above devices, the substrate conveyor 16 and the substrate holding device 17 are fixed to the bed 36 by a plurality of support legs 35, as is clear from FIG. The device 12 and the squeegee device 14 are installed on a movable base 38 that is movable with respect to the bed 36. The movable table 38 is supported by two guide rails 40 arranged parallel to each other on the bed 36 so as to be movable in the left-right direction in FIG. 1 and in the direction perpendicular to the plane of the paper in FIG. . Further, the screen positioning support device 12 and the squeegee device 14 are always in a state of covering the upper part of the substrate positioning support device 10, the substrate conveyor 16, and the substrate holding device 17, but the space above them can be opened by rotation. It is like that. Screen positioning support device 12 and squeegee device 1
A frame 42 supporting 4 is rotatably attached to a pair of columns 44 erected on a movable table 38 by a shaft 46, and is connected to a connecting portion 47 by an actuator (not shown). It can be rotated. The end of the frame 42 remote from the shaft 46 is supported by a column 50 via an adjustment screw 48, thereby connecting the screen positioning support device 12, the squeegee device 14, the substrate positioning support device 10, the substrate conveyor 16, and the substrate. The height relative to the presser support device 17 can be adjusted.

Hereinafter, the configuration of each part of this screen printing apparatus will be explained in detail.

(Substrate Positioning and Supporting Device) As is clear from FIG.
It is equipped with a support plate 62 placed through the support plate 62. That is, a cam rod 66 is provided on the movable table 38 and is supported by a plurality of guide blocks 64 so as to be slidable in the longitudinal direction, and has a slope inclined in the longitudinal direction on its upper surface. 62 is provided with four cam followers 67 having slopes corresponding to the slopes described above, two for each cam rod 66, and the height of the support plate 62 is adjusted as the cam rod 66 moves in the longitudinal direction. It is now possible to adjust the temperature. The two cam rods 66 are connected by a connecting rod 68, and a lead screw 70 parallel to the cam rod 66 is threaded onto the connecting rod 68, and the handle is engaged with the feed screw 70. By rotating the two cam rods 66, the two cam rods 66 can be moved integrally. In addition, the support plate 6
Two guide tubes 72 are fixed to 2 in a posture extending in the vertical direction. Each guide tube 72 is slidably fitted into another guide tube 74 fixed to the movable table 38 to guide the vertical movement of the support plate 62. A spring 76 is disposed between them, and by pulling the support plate 62 toward the movable table 38, the guide block 6
4. The cam rod 66 and the cam follower 67 are kept in close contact with each other to maintain the support plate 62 at an accurate predetermined height.

A rod 78 is slidably fitted into each guide cylinder 72 fixed to the support plate 62, and a longitudinal mounting member 80 extending along the moving direction of the squeegee 28 is fixed to the upper end of the rod 78. ing. Board supports 18 corresponding to printed circuit boards 20 of various sizes are selectively attached to this mounting member 80. A piston rod 84 of a multi-stage cylinder 82 attached to the support plate 62 is fixed to the mounting member 80, and the mounting member 80 and the substrate support stand 18 can be moved to four height positions, namely, a rising end position, a first intermediate position, and a second position. It is adapted to be moved to an intermediate position and a lowering end position. Each of these positions is detected by an approach switch 86 fixed to the mounting member 80 and four detected objects 88 fixed to the support plate 62.

As is clear from FIG. 1, the substrate support 18 has a large number of absorption holes 90 on its upper surface, and each absorption hole 90 connects to an absorption tube 92 through an absorption passage formed inside the substrate support 18 and the mounting member 80. This absorption pipe 92 is connected to a vacuum device via a switching valve (not shown), so that the board support stand 18 attracts and holds the printed circuit board 20 by negative pressure.

(Screen positioning support device) The screen support stand 22 of the screen positioning support device 12 is constituted by a part of the rotatable frame 42. Screen support stand 2
As is clear from FIG. 2, a positioning block 100, a dial gauge 102, and a fixed cylinder 104 are provided on the cylinder 2. The screen support base 22 is a rectangular frame body, and two positioning blocks 100 are disposed on the screen support base 22 along one side, and one positioning block 100 is disposed along the other side perpendicular to the one side. Positioning block 10
0 is placed. Adjustment bolts 106 are screwed into the portions of the screen frame 26 facing each positioning block 100 in a posture perpendicular to each side of the screen frame 26.
A dial gauge 102 is attached to a portion adjacent to the portion that comes into contact with each adjusting bolt 106 of 00.

Therefore, with the adjusting bolt 106 in contact with the positioning block 100, adjust the adjusting bolt 1 while watching the indication on the dial gauge 102.
By rotating the screen frame 26, the position of the screen frame 26 can be adjusted accurately. After the adjustment is completed, the fixed cylinder 104 is operated to fix the screen frame 26 to the screen support base 22, and the numerous small holes formed in the screen 24 become areas on the printed circuit board 20 to which creamy solder is to be applied. It can be fixed in an exact match. Once the position is adjusted in this way, even if the screen frame 26 is removed from the screen support stand 22, the adjustment bolts 106 remain fixed to the screen frame 26, so next, move the screen frame 26 to the screen support stand. 22 does not require any adjustment work when it is installed, improving the efficiency of setup change work. In addition, the screen 24
In this embodiment, the screen is made of a thin stainless steel plate, but it is also possible to use other screens, such as one in which transparent portions are left at predetermined portions of the Tetron mesh and synthetic resin coating is applied to both sides.

(Squeegee device) The squeegee device 14 includes two guide rods 110 disposed horizontally and parallel to each other on the rotatable frame 42, and the guide rods 110.
A slide 112 that slides on the top of the slide 112 is provided. As is clear from FIG. 1, the slide 112 is provided with two pairs of guide tubes 114 separated by a distance in a direction perpendicular to the direction of movement of the slide 112. A mounting member 118 is fixed to the lower ends of the two rods 116 that are vertically slidably fitted into each pair of guide tubes 114.
A squeegee 28 is removably attached to. Each mounting member 118 is raised and lowered by a lifting cylinder 120 shown in FIG. 1, thereby moving the squeegee 28 to a lowered position in contact with the screen 24 and a raised position away from it. A nut 122 is fixed to the slide 112, and a feed screw 124 is attached to the frame 42 so as to be rotatable but immovable in the axial direction.
When the two are screwed together and the feed screw 124 is rotated by the servo motor 126, the squeegee 28 is linearly reciprocated along the screen 24.

(Substrate Conveyor) As is clear from FIG. 1, the substrate conveyor 16 includes, in addition to the fixed rail 30 and the movable rail 32, a frame 130 parallel to these. A plurality of rail feed screws 132 are rotatably but immovably spanned in the axial direction. These rail feed screws 132 are screwed into rail nuts 133 fixed to the movable rail 32 at a distance in its longitudinal direction and perpendicular to its longitudinal direction. All rail lead screws 132 are connected to sprockets 134 and chain 1 shown in FIG.
35, so that they can be rotated by the same amount in the same direction. Therefore, by rotating one rail feed screw 132, the movable rail 32 is moved toward or away from the fixed rail 30 while maintaining an attitude parallel to the fixed rail 30, and the substrate conveyor 16 width can be easily changed.

The rope 33 that supports and conveys the printed circuit board 20 is guided by guide members 136 and 138 fixed to the fixed rail 30 and movable rail 32, respectively, and is driven by a drive pulley attached to a motor (not shown). It's becoming like that. When the printed circuit board 20 carried in by the rope 33 reaches a position directly above the board support stand 18, it is stopped by a stopper device 140 shown in FIG. The stopper device 140 includes a lifting cylinder 142 attached to the support plate 62.
In the raised position, this stopper member 144 comes into contact with the front end of the printed circuit board 20 to prevent further advancement, and in the lowered position, the printed circuit board 20 is prevented from further advancing. is allowed.

The printed circuit board 20 stopped by the stopper device 140 is accurately positioned by the positioning pins 146 shown in FIG. The positioning pins 146 are provided at two locations separated from each other in a direction parallel to the board surface of the printed circuit board 20, and are used to position the printed circuit board by fitting into positioning holes formed in the printed circuit board 20. It is always in the lowered position and is raised as the substrate support stand 18 is raised. That is, the positioning pin 146 is biased in the upward direction by a spring 148, and a protrusion 150 fixed to the positioning pin 146 engages with the lower end of the substrate support base 18, so that the positioning pin 146 is always urged to support the substrate. Since the stand 18 is in the lowered position, the positioning pin 14
6 is also in the lowered position where it does not fit into the positioning hole of the printed circuit board 20. In addition, positioning pin 1
The fact that 46 has risen and fitted into the positioning hole of printed circuit board 20 is detected by proximity switch 152 shown in FIG.

(Movable Rail, Movable Platform Moving Device) As the width of the substrate conveyor 16 is changed, the movable platform 38 can be moved by one-half distance in the same direction as the movable rail 32. As mentioned above, the movable rail 138 has the rail feed screw 132,
It is moved by a rail nut 133, a sprocket 134 and a chain 135, which are further connected to a carriage feed screw 168 by a sprocket 162, a chain 164 and a sprocket 166. The movable table feed screw 168 is rotatably but immovably supported in the axial direction by the bed 36, and a handle 170 is fixed to one end thereof. Movable base feed screw 16
8 is screwed into a movable base nut 172 fixed to the movable base 38 in a position parallel to the rail nut 133. The rail feed screw 132 and the movable table feed screw 168 have the same pitch, but the diameter of the sprocket 166 is different from that of the sprocket 134.
Since the rotation transmission mechanism consisting of the chains 162, 166 and the chains 135, 164 is supposed to transmit rotation at twice the speed, when the movable base feed screw 168 is rotated by the handle 170, the rail feed The screw 132 is rotated at twice the speed and eventually the movable rail 32 is rotated as shown in FIG.
When is moved by a distance l, the movable base 38 is moved by l/2 in the same direction.
In this embodiment, a moving device that moves the movable rail 32 and the movable base 38 in conjunction with each other is provided by the rotation transmission mechanism, the rail feed screw 132, the rail nut 133, the movable base feed screw 168, and the movable base nut 172. It is composed of

(Screen holder) As shown in FIG. 3, a screen holder 182 is fixed to the movable rail 32 by a support member 180, and together with a screen holder 186 fixed to the fixed rail 30 by a support member 184, the screen The support member 180 supports the middle part of the rail feed screw 1 from below.
The movable rail 32 is supported by the support plate 62 via a guide rod 188 parallel to the movable rail 32, and the difference in the amount of movement between the movable rail 32 and the movable base 38 is allowed by the sliding movement of the support member 180 with respect to the guide rod 188. It's summery. Further, the support member 184 is supported by the support plate 62 via a sliding member 190,
This allows relative movement between the support member 184 and the support plate 62.

(Substrate holding device) As is clear from FIG. 3, the substrate holding device 17 includes a pair of holding plate guides 200 fixed to the support members 180 and 184, respectively. The holding plate guide 200 has a U-shaped cross section, and engages with both side edges of the substrate holding plate 34 to limit the movable direction of the substrate holding plate 34 to one direction. That is, movement of the substrate holding plate 34 in the vertical direction (direction parallel to the moving direction of the substrate support stand 18) and in a direction perpendicular to the vertical direction and the conveyance direction of the substrate conveyor 16 is prevented, and the movement in the conveyance direction of the substrate conveyor 16 is prevented. It is designed to only allow movement in the direction parallel to . However, the presser plate guide 20
0 has an L-shaped cross section by removing a portion that engages the side edge of the substrate holding plate 34 from above at a portion away from the upper position of the substrate support stand 18. Board holding plate 3
4 can be removed upwards.

Further, a bar 202 is disposed parallel to the fixed rail 30 and the presser plate guide 200 so as to be movable in the longitudinal direction while being guided by a guide member (not shown). As shown in FIG. 4, an endlessly wound chain 204 is connected to the chain 20.
The bar 202 is moved in the longitudinal direction by being driven by a chain drive device 4 comprising a sprocket, a motor, etc. (not shown). Engagement members 206 are attached to two locations separated in the longitudinal direction of this bar 202, and as the bar 202 moves, these engagement members 206
06 engage with the front and rear ends of the substrate holding plate 34 to move the substrate holding plate 34 along the holding plate guide 200.

(operation) Next, the operation of this printing press will be explained.

When printing for one type of printed circuit board 20 is finished, the board support stand 18, screen 24, squeegee 28, and board holding plate 34 that have been installed for that printed circuit board 20 are removed.
are removed, and the handle 170 shown in FIG. 2 is rotated to adjust the width of the board conveyor 16 to a width suitable for the printed circuit board 20 to be printed next. At this time, the rail feed screw 132 and the movable base feed screw 1
68 is connected by the rotation transmission mechanism consisting of the sprocket 134 etc. as mentioned above,
As the movable rail 32 is moved relative to the fixed rail 30, the movable platform 38 is moved in the same direction by a half distance. Therefore, the substrate positioning and supporting device 10, screen positioning and supporting device 12, and squeegee device 14 installed on the movable table 38 also move by half the moving distance of the movable rail 34, and the substrate conveyor 16 Even if the width of the substrate conveyor 16 and the substrate holding device 17 is changed, the widthwise centers of the substrate support 18, the screen 24, and the squeegee 28 are maintained in agreement.

Once the width of the board conveyor 16 has been adjusted, the board support stand 18, screen 24, squeegee 28, and board holding plate 34 corresponding to the new printed circuit board 20 are attached to the mounting member 80, screen support stand 22, mounting member 118, and Attach to the presser plate guide 200. This completes the setup change work.

When the printing machine is started, first the substrate conveyor 16
As shown in FIG. 5a, the printed circuit board 20 is carried between the board support stand 18 at the lower end position and the screen 24 above it, and the board holding plate 34 is moved to the operating position. It will be done. When the printed circuit board 20 reaches above the board support stand 18, the stopper device 140 prevents the printed circuit board 20 from moving further.

Subsequently, the substrate support stand 18 is raised by the multistage cylinder 82 to the first intermediate position shown in FIG. 5b. In this process, the board support stand 18 scoops up the printed circuit board 20 from below, and at the same time, the positioning pins 146 fit into the positioning holes of the printed board 20, and the printed board 20 is moved to the board support stand 18.
Position accurately against. After this positioning, the board support stand 18 reaches the first intermediate position, and the printed circuit board 20 is pressed against the board support stand 18 by the board holding plate 34. In this state, the absorption tube 92
Negative pressure is supplied to the printed circuit board 20, so that the printed circuit board 20 is reliably attracted to the board support stand 18.

Subsequently, as shown in FIG. 5c, the substrate support stand 18 is
is lowered to the second intermediate position, and the printed circuit board 20 held thereby is slightly separated from the board holding plate 34. Thereafter, the substrate holding plate 34 is retracted from the position above the substrate support stand 18, as shown in FIG. 5d. Therefore, the substrate support stand 18
can be raised to the upper end position as shown in FIG.

Subsequently, in FIG. 2, the left squeegee 28 is raised, and the right squeegee 28 is moved from right to left while contacting the top surface of the screen 24.
A portion of the creamy solder that is pushed over the screen 24 by the right squeegee 28 appears on the screen 2.
It is pushed into a large number of small holes formed in 4 and attached to the upper surface of the printed circuit board 20. After passing above the printed circuit board 20, the right squeegee 28
is raised, the left squeegee 28 is lowered, and the next printed circuit board 20 is ready to be printed by moving the left squeegee 28 from left to right.

When the creamy solder is applied in this way, the widthwise center of the board conveyor 16 and the widthwise center of the printing mechanism including the squeegee device 14 and the like coincide with each other as described above. Substrate support stand 18, screen 24 and squeegee 2
8 also coincides with each other in the width direction, so that the thickness of the cream solder printed on the printed circuit board 20 does not become non-uniform in the width direction of the printed circuit board 20.

After the above operation, the board support stand 18 is lowered to the lower end position, and the printed circuit board 20, which has been printed, is
is again supported by the substrate conveyor 16. Therefore, when the stopper member 144 of the stopper device 140 is lowered and the rope 33 of the board conveyor 16 is driven, the printed printed circuit board 20 is carried out from the position above the board support stand 18, and one cycle of the printed circuit board 20 is carried out. The printing operation ends.

In the embodiment detailed above, the rail feed screw 132 for moving the movable rail 32 of the substrate conveyor 16 and the movable table feed screw 168 for moving the movable table 38 are of the same pitch, and the sprocket 134 The rotation of the movable base feed screw 168 is doubled and transmitted to the rail feed screw 132 by the rotation transmission mechanism consisting of the above, so that the amount of movement of the movable base 38 becomes twice the amount of movement of the movable rail 32. It was supposed to be 1/1. However, the rail feed screw 132 and the movable base feed screw 16
It is not essential to have the same pitch as 8.
In other words, the product of the pitch and rotation speed of the rail feed screw 132 should be twice the product of the pitch and rotation speed of the movable base feed screw 168.

Furthermore, if the rotation transmission mechanism that rotates the rail feed screw 132 and the movable base feed screw 168 in conjunction with each other is composed of a sprocket and a chain as in the above embodiment, there is an advantage that the manufacturing cost is low. It is not limited to this,
It is also possible to employ other rotation transmission mechanisms such as gear trains. Furthermore, the moving device that fluidly moves the movable rail 32 and the movable base 38 is not limited to one that includes the rail feed screw 132 and the movable base feed screw 168; for example, the movable base feed screw 168 is omitted. The movable rail 32 is moved by a lever device with a lever ratio of 1/2.
8 may be transmitted.

Further, the board conveyor device that transports the printed circuit board 20 is not limited to a board conveyor equipped with an endlessly wound rope 33, but, for example, a push-pull cylinder can be used to transport the printed circuit board 20 along a fixed rail and a movable rail. There is no problem even if it is a device that carries printed circuit boards.

In addition, it goes without saying that the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art, although not illustrated individually.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the main parts of a printed circuit board screen printing machine which is an embodiment of the present invention. FIG. 2 is a partially cutaway front view of the main parts of the printing press. FIG. 3 is an enlarged side sectional view showing the vicinity of the substrate conveyor in FIG. 1. Figure 4 is a view in the direction of arrow A in Figure 3 (however,
(The presser plate guide is omitted). Figure 5 a, b,
c, d, and e are explanatory diagrams schematically showing different operating states of the printing press. 10: Substrate positioning support device, 12: Screen positioning support device, 14: Squeegee device, 1
6: Board conveyor (board transport device), 17: Board holding device, 18: Board support stand, 20: Printed circuit board, 22: Screen support stand, 24: Screen, 26: Screen frame, 28: Squeegee, 3
0: Fixed rail, 32: Movable rail, 33: Rope, 34: Board holding plate, 38: Movable base, 80: Mounting member, 82: Multistage cylinder, 118: Mounting member, 120: Elevating cylinder, 124: Feed screw,
126: Servo motor, {132: Rail feed screw, 133: Rail nut, 134: Sprocket, 135: Chain, 162: Sprocket,
164: Chain, 166: Sprocket, 16
8: Movable base feed screw, 172: Movable base nut}
(mobile device).

Claims (1)

[Claims] 1. A substrate support stand, a screen support stand, and a squeegee, the squeegee linearly moving over the screen supported by the screen support stand. In a screen printing machine that prints adhesive, creamy solder, etc. on a printed circuit board, the board support stand, screen support stand, and squeegee are installed on a movable stand that can be moved in a direction perpendicular to the direction of movement of the squeegee. In addition, a substrate transport device is provided for carrying the printed circuit board into and/or carrying out the printed circuit board between the board support stand and the screen support stand in a direction parallel to the moving direction of the squeegee, and the board transfer device includes: A printed circuit board with different widths, comprising a fixed rail that guides one side edge of the printed circuit board, and a rail that can approach and move away from the fixed rail and guide the other side edge of the printed circuit board. shall be capable of transporting
and moving the movable rail toward and away from the fixed rail and moving the movable platform in the same direction as the moving direction of the movable rail and by half the distance in conjunction with the movement of the movable rail. A printing device characterized in that the widthwise centers of the substrate support stand, the screen support stand, and the squeegee are always aligned with each other regardless of changes in the width of the substrate transfer device. Board screen printing machine. 2. The moving device includes: a rail nut fixed to the movable rail at a distance in the longitudinal direction of the movable rail and in an attitude perpendicular to the movable rail; A rail feed screw screwed into the rail nut; a movable nut fixed to the movable base in a position parallel to the rail nut; and a movable nut screwed to the movable base nut and rotatable but not movable in the axial direction. The movable base feed screw, the movable base feed screw and the rail feed screw, the product of the pitch and the rotation speed of the rail feed screw is:
2. The printed circuit board screen printing machine according to claim 1, further comprising a rotation transmission mechanism connected to the movable base feed screw so that the rotation speed is twice the product of the pitch and the number of revolutions.