JP2000037847A - Screen printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a mask sheet to be used alone and prevent the warping of the mask sheet in use. SOLUTION: A screen printer is constituted of a mask sheet holding mechanism 10 holding a mask sheet S provided above a lifting and lowering printing stage 3 holding a base W and a squeegee unit 40 provided above the mask sheet holding mechanism. The mask sheet holding mechanism 10 is provided with claming mechanisms 11a and 11b clamping both end edges of the mask sheet S in the X axial direction and clamping mechanisms 12a and 12b claming both end edges in the mask sheet S in the Y axial direction. The clamping mechanisms 11a and 11b are so constituted as to move close to and away from rleasably in the X direction, and the clamping mechanisms 12a and 12b are so constituted as to move close to and away from releasably in the Y axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus for screen-printing a paste such as cream solder on a substrate.

[0002]

2. Description of the Related Art Conventionally, a screen mask for screen printing (hereinafter, abbreviated as a mask) is mounted on a substrate set on a stage, and paste such as cream solder, conductive paste, or resistive paste supplied on the mask is applied. The paste is printed (applied) at a predetermined position on the substrate through an opening formed in the mask by expanding with a squeegee.
Screen printing devices adapted to do so are generally known.

In such an apparatus, the mask is:
For example, a mask sheet having the above-described opening formed in a sheet made of stainless metal, brass, or the like is provided, and the mask sheet is assembled to a frame with a predetermined tension. Then, a plurality of types of masks are prepared for each pattern to be printed, and these masks can be properly used depending on the type of the substrate and the like.

[0004]

However, the mask is
Due to the framework as described above, there is a problem that the space and the weight tend to be bulky, which is inconvenient for storage and handling, and that there is also a labor for a setup change operation (that is, a mask replacement operation). Therefore, conventionally, it has been desired that printing can be performed using only a mask sheet.

[0005] However, the frame of the mask prevents the deflection of the mask sheet when the mask sheet is superimposed on the substrate, and ensures that the entire mask sheet can be overlaid on the substrate surface. When practically using screen printing with only a sheet, it is necessary to solve the problem of the deflection.

In recent years, a band-shaped mask sheet in which a plurality of pattern forming regions, that is, regions in which the openings are formed, is arranged in a horizontal line, and both ends thereof are disposed on both sides of the stage. A so-called roll screen mask type screen printing apparatus is used in which a desired pattern forming area is drawn out on a stage and is used for printing while removing the frame from the mask while rotating the drum. Although proposed (JP-A-5-124176), this apparatus does not solve the problem of mask deflection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a screen printing apparatus which can be used with only a mask sheet and which can effectively prevent deflection of the mask sheet in use. It is intended to provide.

[0008]

In order to solve the above-mentioned problems, the present invention provides a method in which a paste is supplied onto a mask sheet mounted on a substrate, and the paste is extended by a squeegee to form a predetermined sheet formed on the mask sheet. In a screen printing apparatus for printing a paste on a substrate through an opening of a pattern, a stage for supporting the substrate, sheet holding means for detachably holding a mask sheet, and a substrate from a position where the mask sheet is overlaid on the substrate And a movable unit for relatively moving the stage and the sheet holding unit over a position where the mask sheet is separated from the mask sheet. The holding unit holds the sheet holding unit in a state in which a peripheral edge portion of the mask sheet is clamped. In a reduced state that allows the attachment and detachment of the mask sheet, and the mask sheet is positioned in at least two directions on at least the sheet surface. In an enlarged state stretched by the force it is obtained by configured to be scaled (claim 1).

According to this apparatus, the mask sheet is held by the sheet holding means, and the stage and the sheet holding means are relatively moved by the movable means, so that the mask sheet is mounted on the substrate. Then, screen printing is performed in this state. During printing, the sheet holding means is in an enlarged state and the mask sheet is stretched in two or more directions on the sheet surface, so that the deflection of the mask sheet is effectively prevented.

In such an apparatus, in particular, there is provided a strip-shaped mask sheet in which a plurality of pattern forming regions each having the above-mentioned opening formed therein are arranged in the longitudinal direction, and both ends of the mask sheet are wound around a pair of drums. In a device that is rotated and selectively derives a pattern forming area to be used for printing to a work position between drums according to the rotation of each drum,
The seal holding means is configured to hold a peripheral portion of each pattern forming region led to the work position (claim 2).

According to this apparatus, in a so-called roll screen mask type screen printing apparatus, it is possible to prevent deflection of a pattern forming area of the mask sheet S which is particularly used for printing.

In this case, a cleaning mechanism for wiping and removing the paste adhered to the mask sheet as the mask sheet is wound by the drum is provided between the work position and the drum on both sides thereof. (Claim 3) is preferred. This prevents the paste from remaining on the mask sheet wound around the drum after printing, and prevents the mask sheet, the drum, and the like from being stained with the paste.

[0013] The sheet holding means may be formed in a hollow square shape having two sets of clamp portions extending in parallel with each other, so that the opposing clamp portions can be relatively moved toward and away from each other ( Claim 4).

In this case, the periphery of the mask sheet S is clamped in a rectangular shape, and the mask sheet S is stretched in two directions orthogonal to each other on the sheet surface as the clamp member moves. Therefore, the sheet holding means can be obtained with a simple configuration.

Further, a pair of clamping members for clamping the mask sheet are provided in each clamp portion, and a plurality of pin members and relief holes of the pin members are arranged in parallel with each other in these clamping members.
At the time of clamping, the mask sheet is clamped by the clamping member while the pin member is passed through the through hole formed at the clamping position of the mask sheet. , And can be held firmly.

It is preferable that the sheet holding means be capable of adjusting the tension applied to the mask sheet in a state where the mask sheet is stretched, so that the adjusted tension can be maintained. This makes it possible to arbitrarily adjust the tension of the mask sheet during printing according to the strength of the mask sheet and the like.

[0017]

Embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of a screen printing apparatus according to the present invention. As shown in these figures, a printing stage 3 for supporting a printed circuit board W is disposed on a base 1 of a screen printing apparatus, and the printed circuit board W is loaded into and unloaded from the printing stage 3. Conveyor 2a and carry-out conveyor 2b are arranged on both sides of the printing stage 3. Although not shown in detail, the printing stage 3 is an XY table 5 provided on the base 1.
The printing stage 3 is supported on the upper side via a lifting / lowering rotation unit 4, so that the printing stage 3 can be moved in the X-axis direction (the conveyors 2 a and 2 b).
), The Y-axis direction (direction orthogonal to the X-axis on the horizontal plane), the Z-axis direction (up-down direction), and the θ-direction (rotation around the Z-axis).

Above the printing stage 3, a mask sheet holding mechanism 10 (sheet holding means) is provided.

As shown in FIG. 1, the mask sheet holding mechanism 10 (hereinafter, simply referred to as a holding mechanism 10) is configured to hold a peripheral edge of a mask sheet S formed in a square shape in plan view in a clamped state. It is provided with a pair of clamp mechanisms 11a and 11b for clamping both edges in the X-axis direction, and a pair of clamp mechanisms 12a and 12b for clamping both edges in the Y-axis direction.

The clamp mechanisms 11a and 11b are shown in FIG.
3, a rectangular cylindrical sub-frame 14 extending in the X-axis direction, and a pair of upper and lower holders 16a, which are elongated in the Y-axis direction, for holding the mask sheet S inside the frame 14, are shown. 16b (clamping member).

Of these holders 16a and 16b, the upper holder 16a is fixed to the rod end (lower end) of an air cylinder 19 fixed to the top plate 15a of the frame 14, and the lower holder 16b is fixed to the bottom plate of the frame 14. 15b is fixed to face the holder 16a. Further, among the holders 16a and 16b, a plurality of fixing pins 17 projecting at regular intervals in the Y-axis direction are formed on the upper holder 16a so as to penetrate through the through holes for clamping formed in the peripheral edge of the mask sheet S. And a fixing pin 17 is provided on the lower holder 16b.
An escape hole 18 is formed in correspondence with. Then, in the clamp mechanisms 11a, 11b, the clamp mechanisms 11a, 1
1b, the upper holder 16a is held at the raised position and the holders 16a and 16b are separated from each other. In the clamped state of the clamp mechanisms 11a and 11b from which the rods of the air cylinder 19 protrude, both holders 16a and 16b are in the clamped state.
a, 16b are pressed against each other and each fixing pin 17
8

Although not shown, the base 1 has
A main frame (not shown) for supporting the mask sheet holding mechanism 10 is provided, and each of the clamp mechanisms 11a and 11b is attached to the main frame via the sub-frame 14. In particular,
With respect to the clamp mechanism 11b on the carry-out conveyor side, the sub-frame 14 is mounted movably in the X-axis direction with respect to the main frame, whereby the clamp mechanism 11a,
11b is relatively releasable.

That is, as shown in FIG. 2, a support 20 extending in the Y-axis direction is fixed to the main frame, and a pair of fixed rails 21 extending in the X-axis direction are laid on the support 20. The frame 14 of the clamp mechanism 11b is movably mounted on the fixed rail 21. Further, the air cylinder 22 is fixed to the support base 20,
The rod end of the air cylinder 22 is
It is connected to the. As a result, the clamp mechanism 11b moves with the operation of the air cylinder 22, and each clamp mechanism 1
1a, 11b can be relatively displaced between a position where it approaches and a position where it separates.

On the other hand, the clamp mechanisms 12a, 1 for clamping both edges in the Y-axis direction of the mask sheet S, respectively.
2b basically has the same configuration as the clamp mechanisms 11a and 11b.

As shown in FIGS. 1 and 4, each of the clamp mechanisms 12a and 12b has a plate-shaped sub-frame 25 extending in the X-axis direction, and is fixed to the sub-frame 25 above the sub-frame 25. And an elevating plate 27 which is raised and lowered by the operation of the air cylinder 26.

On the opposing surfaces of the lifting plate 27 and the frame 25, elongated holders 28a and 28b (holding members) in the X-axis direction for holding the mask sheet S are fixed, respectively. Among them, the upper holder 28a is provided with a plurality of fixing pins 29 for penetrating through the through holes for clamping formed in the peripheral edge of the mask sheet S at regular intervals in the X-axis direction. An escape hole 30 is formed in the holder 28b so as to correspond to the fixing pin 29. In the clamp mechanisms 12a and 12b, when the clamp mechanisms 12a and 12b in which the rods of the air cylinder 26 protrude are not clamped, the upper holder 28a is held at the raised position, and the two holders 28a and 12b are held.
When the clamp mechanism 12a, 12b with the rod of the air cylinder 26 retracted is in a clamped state, the holders 28a, 28b are pressed against each other, and the fixing pins 29 project into the relief holes 30. I have.

Each of the clamp mechanisms 12a and 12b is attached to the main frame via the sub-frame 25, but one of the clamp mechanisms 12b (FIG. 1).
In the upper clamp mechanism), the frame 2
5 is attached to the main frame so as to be movable in the X-axis direction, whereby the clamp mechanisms 12a and 12b
Are relatively releasable.

That is, as shown in FIG. 4, a support base 31 is fixed to the main frame, and a pair of fixed rails 32 extending in the Y-axis direction are laid on the support base 31. The frame 25 of the clamp mechanism 12b is movably mounted. Further, an air cylinder 33 is fixed to the support base 31, and the rod end of the air cylinder 33 is connected to the frame 25. Accordingly, the clamp mechanism 12b moves with the operation of the air cylinder 33, so that the clamp mechanisms 12a and 12b can be relatively displaced between the approached position and the separated position.

In the mask sheet holding mechanism 10, the mask sheet S can be attached to and detached from the mask sheet holding mechanism 10 when the clamp mechanisms 11a and 11b and the clamp mechanisms 12a and 12b are both in the approaching position. Each interval is set. That is, the holding of the mask sheet S by the mask sheet holding mechanism 10 is performed by passing the fixing pins 17 and 29 through the through holes formed in the peripheral portion of the mask sheet S as described above.
a, 16b and 28a, 28b
Between the clamping mechanisms 11a, 1
The fixing pins 17 and 29 and the through holes of the mask sheet S are aligned with each other when both the clamp mechanism 1b and the clamp mechanisms 12a and 12b are in the approach position.

The mask sheet holding mechanism 10 includes:
The tension applied to the mask sheet S in a state where the mask sheet S is stretched can be adjusted, and the adjusted tension can be maintained. Specifically, the clamp mechanisms 11b, 12
The supply air pressure to the air cylinders 22 and 33 for moving b can be adjusted.

That is, as shown in FIG. 2, the air circuit 34 for the air cylinder 22 includes a clamp mechanism 11.
a, 11b approaching and the clamping mechanism 11a, 1
A switching valve 35 for switching the operation state of the air cylinder 22 between a state in which the air cylinder 1b is separated from the operation state is provided, and an electropneumatic regulator 36 for adjusting the pressure of air supplied to the air cylinder 22 is provided. As shown in FIG. 4, the air circuit 37 for the air cylinder 33 is also provided with a switching valve 38 for switching the operation state of the air cylinder 33, and an electropneumatic device for adjusting the pressure of the air supplied to the air cylinder 33. A regulator 39 is provided.

The tension applied to the mask sheet S is numerically set by an operator using an input device (not shown), and the electropneumatic regulators 36 and 3 are provided by a control device (not shown).
9 is controlled to be adjusted.

Above the mask sheet holding mechanism 10, a squeegee unit 40 is movably supported.

As shown in FIG. 2, the squeegee unit 40 has two squeegees 41 for forward movement and backward movement.
a and 41b are juxtaposed in the X-axis direction. Among the squeegees 41a and 41b, the forward squeegee 41a (the squeegee on the left side in the figure) has an inclination angle set so as to form an acute angle with the mask sheet S toward the carry-out conveyor 2b, and is used for the backward movement. The squeegee 41b (the right squeegee in the figure) is inclined at an acute angle with the mask sheet S toward the carry-in conveyor 2a.

The squeegees 41a and 41b are attached to the rod ends (lower ends) of air cylinders 43a and 43b fixed to the frame 42 of the squeegee unit 40, respectively. On the other hand, it is supported so that it can be individually raised and lowered.

Although not shown, the frame 42 of the squeegee unit 40 is attached to the main frame via a lifting mechanism and a moving mechanism in the X-axis direction, and the squeegee unit is moved by the lifting mechanism. The squeegee unit 40 can be reciprocated in the X-axis direction by moving the squeegee unit 40 up and down. Then, at the time of printing, the squeegee unit 40 is reciprocated in the X-axis direction, and during this reciprocation, at the time of forward movement, the squeegee 41a for forward movement is set at the lower end position, and the paste is expanded by the squeegee 41a. At the time of the backward movement, the squeegee 41b for the backward movement is set at the lower end position (the state shown in FIG. 2), and the paste is expanded by the squeegee 41b. During printing, the pressing force of the squeegees 41a and 41b on the mask sheet S is adjusted by adjusting the height of the squeegee unit 40 with respect to the mask sheet S by the lifting mechanism.

Next, the printing operation by the screen printing apparatus will be described together with the operation and effect.

In the screen printing apparatus configured as described above, first, prior to printing, a preparation operation for holding the mask sheet S by the mask sheet holding mechanism 10 is manually performed by an operator.

In the preparatory work, first, the air cylinder 22 is operated, for example, the clamp mechanisms 11a and 11b are set to the approach position, and the air cylinder 33 is operated to move the clamp mechanisms 12a and 12b to the separated position. set. At this time, each of the clamp mechanisms 11a, 11b, 1
2a and 12b are all in the non-clamp state.

In this state, both edges of the mask sheet S in the X-axis direction are held by the holders 1 of the clamping mechanisms 11a and 11b.
6a, 16b, and then the air cylinder 33
Is operated to set the clamp mechanisms 12a and 12b at the approach position, and the both ends of the mask sheet S in the Y-axis direction are interposed between the holders 28a and 28b of the clamp mechanisms 12a and 12b.

Then, each of the clamp mechanisms 11a, 11b,
The mask sheets S are held by the mask sheet holding mechanism 10 by switching 12a and 12b to the clamped state. At this time, since the through hole is formed in the peripheral portion of the mask sheet S as described above, the fixing pins 17, 29 of the clamp mechanisms 11a, 11b, 12a, 12b are formed in the through hole.
The mask sheet S is clamped while passing through.

Next, the air cylinders 22 and 33 are operated, and the clamp mechanisms 11a and 11b and 12a and 12b
Are moved in the separating directions. That is, the mask sheet S is thereby stretched in the X-axis direction and the Y-axis direction.

In this case, as described above, the air cylinder 2
Since the air pressure is adjustable in the air circuits 34 and 37 for the mask sheets 2 and 33, the operator can arbitrarily adjust the tension applied to the mask sheet S according to the strength and the like of the mask sheet S.

When the above preparation work is completed, for example, a printing operation is started when an operator operates a switch on an operation panel (not shown).

When the printing operation is started, first, the substrate W is conveyed by the carry-in conveyor 2a, and the print stage 3 is moved to a predetermined substrate transfer position near the carry-in conveyor, thereby the substrate W Is transferred from the conveyor 2 onto the printing stage 3, and the substrate W is held on the printing stage 3.

When the substrate W is delivered, the printing stage 3
Moves below the mask sheet S, and the X, Y, and θ directions are determined with respect to the mask sheet S.
The printing stage 3 is raised, and the mask sheet S is mounted on the surface of the substrate W. At this time, since the mask sheet S is held by the mask sheet holding mechanism 10 in a stretched state, the mask sheet S does not bend, and the mask sheet S Will be mounted.

When the mask sheet S is overlaid on the substrate W,
A predetermined amount of paste is supplied onto the mask sheet S by a paste supply nozzle (not shown) or the like, and the squeegee unit 40 is set at a predetermined height and reciprocated in the X-axis direction. Thus, the paste is printed on the substrate W through the openings formed in the mask sheet S while being expanded on the mask sheet S. On this occasion,
As described above, the squeegees 41a and 41b are selectively used for the forward movement and the backward movement of the squeegee unit 40, so that the paste is efficiently expanded.

When the printing of the paste on the substrate W is completed, the printing stage 3 moves to a predetermined substrate delivery position near the unloading conveyor, thereby transferring the substrate W from the printing stage 3 to the unloading conveyor 2b. Then, it is carried out to the next process.

As described above, in the above screen printing apparatus, the mask sheet S is held by the mask sheet holding mechanism 10 in a stretched state and used for printing, so that the mask sheet S does not bend during printing. . Therefore, while performing the screen printing using only the mask sheet S as described above, it is possible to reliably avoid the printing deviation or the like due to the deflection, and to appropriately print the paste on the substrate W. Can be.

In particular, in the mask sheet holding mechanism 10, two sides of the mask sheet S formed in a square shape in plan view and opposed to each other in the X axis direction are clamped by the clamping mechanisms 11a and 11b. Edge clamping mechanism 12
a and 12b, respectively, and in this state, the clamp mechanisms 11a and 11b and the clamp mechanisms 12a and
12b are separated from each other so that the X-axis direction and Y
Since it is stretched in the axial direction, deflection is more effectively prevented. That is, for example, it is conceivable to stretch the mask sheet S only in the X-axis direction of the mask sheet S. In this case, for example, the mask sheet S may be wavy in the Y-axis direction. However, if the mask sheet S is stretched in the X-axis direction and the Y-axis direction as described above,
Such waving does not occur and the mask sheet S
Can be held flat. Next, a second embodiment of the screen printing apparatus according to the present invention will be described. Since the basic configuration of the screen printing apparatus according to the second embodiment is common to that of the first embodiment, the same parts as those of the apparatus according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Only the points will be described in detail.

FIG. 5 and FIG. 6 show a second embodiment of the screen printing apparatus. The screen printing apparatus shown in this figure is a so-called roll screen mask type screen printing apparatus. As shown in the figure, a band-shaped mask sheet is provided on both outer sides (left and right outer sides in the figure) of the clamping mechanisms 11a and 11b. A pair of drums 50a, 5 wound with S
0b.

Of these drums 50a and 50b, the drum 50a on the carry-in conveyor side is rotatably supported by the sub-frame 14 of the clamp mechanism 11a, and is driven by the drive motor 52 attached to this sub-frame 14 via the speed reduction mechanism 51. Are linked. On the other hand, the drum 50b on the unloading conveyor side is rotatably supported by the support table 20, and a drive motor 54 attached to the support table 20 is provided with a reduction mechanism 53.
Are connected via

A plurality of pattern forming regions for paste printing are formed in the mask sheet S in the longitudinal direction, and these pattern forming regions are selectively used for printing. That is, as shown in FIG. 6, the mask sheet S passes between the holders 16a and 16b of each of the clamp mechanisms 11a and 11b, and the two drums 50a and 50b.
While being wound from one drum to the other drum by the driving of the motors 52 and 54,
A predetermined pattern formation area is selectively led out above the printing stage (work position).

Each of the clamp mechanisms 11a and 11b is provided with a cleaning mechanism for the mask sheet S.

More specifically, each clamp mechanism 11
a and 11b are a pair of upper and lower cleaning pads 55a and 55 which are elongated in the Y-axis direction for holding the mask sheet S.
5b is provided. These pads 55a, 55b
Is the holder 16 in each of the clamp mechanisms 11a and 11b.
a, 16b and the drum 50a (or 50b), and the upper pad 55a is fixed to the rod tip (lower end) of the air cylinder 56 fixed to the top plate 15a of the frame 14, and this air cylinder 56 can be moved up and down by the operation of the lower pad 55b.
4 is fixed to the bottom plate 15b. Each upper pad 55a is connected to a suction device 58 via a hose 57.

That is, by holding the mask sheet S between the pads 55a and 55b of the clamp mechanisms 11a and 11b, the paste adhered to the mask sheet S is wiped off as the mask sheet S is wound up. The cleaning mechanism is configured so that the wiped paste is suctioned and removed by the suction device 58 via the hose 57.

Incidentally, also in this embodiment, in order to be able to adjust the tension applied to the mask sheet S, the clamping mechanism 11b is used.
As shown in FIG. 6, a switching valve 35 and an electropneumatic regulator 36 are provided in the air circuit 34 for the air cylinder 22 for moving the clamp mechanism 12b, and the air circuit 33 is also switched to the air circuit for the air cylinder 33 for moving the clamp mechanism 12b. A valve and an electropneumatic regulator (similar to FIG. 4) are provided.

Next, the printing operation by the screen printing apparatus according to the second embodiment will be described together with the function and effect.

In this screen printing apparatus, as a preparatory operation, an operation of drawing out and holding a desired pattern forming area of the mask sheet S above the printing stage 3 is performed.

In the preparatory work, first, the air cylinder 22 is operated, and for example, the intervals between the respective clamp mechanisms 11a and 11b and the respective clamp mechanisms 12a and 12b are set to the close positions. At this time, each of the clamp mechanisms 11a, 11
b, 12a, and 12b are all set in the non-clamp state. In particular, regarding each of the clamp mechanisms 12a and 12b,
The mask sheet S is interposed between the holders 28a and 28b.

In this state, while driving the motors 52 and 53 to take up the mask sheet S from the drum 50a (or 50b) on one side to the drum 50b (or 50a) on the other side, a desired pattern formation area is formed. Place in the working position.

Then, each of the clamp mechanisms 11a, 11b,
12a and 12b are switched to the clamped state, whereby each of the holders 16a and 16b of each of the clamp mechanisms 11a and 11b is switched.
And each holder 28a of each clamping mechanism 12a, 1b,
The peripheral portion of the mask sheet S is clamped by 28b. At this time, a through hole for clamping is formed in a peripheral portion of each pattern forming region of the mask sheet S, and each of the clamp mechanisms 11a, 11b, 12a, 1 is formed in this through hole.
The mask sheet S is clamped while passing the fixing pins 17 and 29 of 2b.

Next, the air cylinders 22 and 33 are operated, and the clamp mechanisms 11a and 11b and the clamp mechanism 1 are operated.
2a and 12b are set at the separated positions. As a result, the portion of the pattern forming area to be printed is stretched in the X-axis direction and the Y-axis direction.

When the above preparatory work is completed, the operator operates a switch on an operation panel (not shown) to start a printing operation. The printing operation is described in the first section.
This is performed in the same manner as in the screen printing device of the embodiment.

When the printing of the paste on the substrate W is completed, the printing stage 3 is moved to a predetermined substrate transfer position near the unloading conveyor, whereby the substrate W is transferred from the printing stage 3 to the unloading conveyor 2b. And carried out to the next process.

When the substrate W is carried out, the cleaning operation of the mask sheet S by the cleaning mechanism is performed in parallel. That is, each clamp mechanism 1
The mask sheet S is clamped between the pads 55a and 55b by the operation of the air cylinder 56 of 1a and 11b, and the mask sheet S is moved from the one drum 50a (or 50b) to the other by the operation of the motors 52 and 54. It is wound around the drum 50b (or 50a). As a result, the paste adhered to the mask sheet S is removed from the pads 55a,
At the same time, the paste wiped by 55b is removed by suction by the suction device 58 through the hose 57.

According to the screen printing apparatus of the second embodiment as described above, at the time of printing, the mask sheet holding mechanism 1
Since the pattern forming region to be used for printing is held in a stretched state by setting the value of 0, the mask sheet S does not bend in the pattern forming region during printing. Therefore, even in the roll screen mask type screen printing apparatus, it is possible to reliably avoid a printing shift or the like due to the deflection, and to appropriately print the paste on the substrate W.

The screen printing apparatuses according to the first and second embodiments are main examples of the screen printing apparatus according to the present invention, and the specific configuration thereof does not depart from the gist of the present invention. It can be changed as appropriate.

For example, in each of the embodiments, one of the clamp mechanisms 11a and 11b for clamping both edges in the X-axis direction is configured to be movable, and clamps both edges in the Y-axis direction. Clamp mechanism 1
Although one of the clamp mechanisms 12a is configured to be movable among the clamp mechanisms 11a, 1b.
1b may be moved in the X-axis direction, and the clamp mechanisms 12a and 12b may be moved in the Y-axis direction.

In addition to the configuration in which the clamp mechanism 11a and the like are moved using an air cylinder as in the above embodiment, for example, the clamp mechanism 11a and the like are moved using a ball screw mechanism using a motor as a drive source. It may be configured so as to make it. That is, a ball screw extending in parallel with the fixed rail is provided on the support base 20, and the ball screw is screwed into the bottom plate 15b of the frame 14, whereby the clamp mechanism 11a is moved in the X-axis direction by rotating the ball screw. You may do so.

In the first embodiment, the mask sheet holding mechanism 10 has a hollow square shape in which the clamp mechanisms 11a and 11b and the clamp mechanisms 12a and 12b are arranged corresponding to each side of the square mask sheet S. However, for example, when there is an octagonal mask sheet S,
The mask sheet holding mechanism 10 may be formed in a hollow octagon in which a clamp mechanism is arranged corresponding to each side of the mask sheet S. In this case, the mask sheet S may be stretched in three directions by making the clamp mechanisms facing each other detachable from each other. That is, the clamping position of the mask sheet S by the mask sheet holding mechanism 10 and the extending direction of the mask sheet S are appropriately selected in consideration of the specific shape and the like of the mask sheet S so as to reliably prevent deflection during printing. What should I do?

[0072]

As described above, according to the present invention, the mask sheet is detachably held by the sheet holding means, and the stage and the sheet holding means are relatively moved by the movable means at the time of printing. Since the mask sheet is overlaid on the substrate supported above, and the sheet holding means is expanded so that the mask sheet is stretched in two or more directions on the sheet surface, the printing is performed during printing. The deflection of the mask sheet can be effectively prevented. Therefore, it is possible to appropriately print the paste on the substrate while using only the mask sheet, while preventing the occurrence of printing deviation or the like due to bending.

In particular, there is provided a strip-shaped mask sheet in which a plurality of pattern forming regions each having the above-mentioned opening are formed side by side in the longitudinal direction, and both ends of the mask sheet are wound around a pair of drums, respectively. Accordingly, in a device in which a pattern forming area to be provided for printing is selectively derived to a work position between drums, the sheet holding means is configured to hold a peripheral portion of each pattern forming area derived to the work position. By doing so, even in a so-called roll screen mask type screen printing apparatus, the deflection of the mask sheet can be effectively prevented.

Further, if the sheet holding means is formed in a hollow square shape having two sets of clamp portions parallel to each other, and the clamp portions facing each other are configured so as to be relatively close to and separated from each other, The sheet holding means can be obtained with a simple configuration.

Further, a pair of clamping members for clamping the mask sheet are provided at each clamp portion, and a plurality of pin members and relief holes of the pin members are arranged side by side on these clamping members so as to face each other. If the mask sheet is clamped by the clamping member with the pin member penetrating through the through hole formed at the clamp position, the mask sheet can be securely held.
And it can be held firmly.

If the tension applied to the mask sheet can be adjusted by the sheet holding means so that the adjusted tension can be maintained, an appropriate tension can be applied according to the strength of the mask sheet.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a screen printing apparatus (first embodiment) according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1 showing the screen printing apparatus.

FIG. 3 is a view on arrow B of FIG. 1 showing a configuration of a clamp mechanism applied to the screen printing apparatus.

FIG. 4 is a schematic cross-sectional view taken along the line CC of FIG. 1 showing a configuration of a clamp mechanism applied to the screen printing apparatus.

FIG. 5 is a schematic plan view showing a screen printing apparatus (second embodiment) according to the present invention.

FIG. 6 is a sectional view taken along line DD of FIG. 5 showing the screen printing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Conveyor 3 Printing stage 10 Mask sheet holding mechanism 11a, 11b Clamp mechanism 12a, 12b Clamp mechanism 40 Squeegee unit S Mask sheet W Substrate

Claims (6)

[Claims] 1. A screen printing method in which a paste is supplied onto a mask sheet superimposed on a substrate, and the paste is extended by a squeegee to print the paste on the substrate through an opening of a predetermined pattern formed in the mask sheet. A stage for supporting the substrate, a sheet holding unit for detachably holding the mask sheet, and a stage for holding the mask sheet on the substrate and a position for separating the mask sheet from the substrate. And a movable means for relatively moving the mask sheet.The sheet holding means holds the peripheral edge portion of the mask sheet in a clamped state, and allows the mask sheet to be attached and detached in a contracted state. It is configured to be able to expand and contract at least into two or more directions on the seat surface. A screen printing apparatus characterized by the above-mentioned. 2. A belt-shaped mask sheet in which a plurality of pattern forming regions each having the opening formed therein are arranged in the longitudinal direction, and both ends of the mask sheet are wound around a pair of drums, respectively. An apparatus for selectively leading a pattern forming area to be provided for printing to a work position between drums according to rotation, wherein the sheet holding means holds a peripheral portion of each pattern formation area led to the work position. The screen printing apparatus according to claim 1, wherein the screen printing apparatus is configured to perform the above operation. 3. A cleaning mechanism is provided between the working position and a drum on both sides of the cleaning position for wiping and removing paste adhered to the mask sheet as the mask sheet is wound by the drum. Claim 2
A screen printing apparatus as described in the above. 4. The sheet holding means is formed in a hollow square shape having two sets of clamp portions extending in parallel with each other, and the opposed clamp portions are configured to be relatively close to and separated from each other. The screen printing apparatus according to claim 1, wherein: 5. Each of the clamp portions has a pair of holding members for holding the mask sheet, and a plurality of pin members and relief holes of the pin members are provided in parallel with each other on the holding members. 5. The screen printing method according to claim 4, wherein the mask sheet is clamped by the clamping member while the pin member is passed through a through hole formed at a clamping position of the mask sheet. apparatus. 6. The sheet holding means according to claim 1, wherein the tension applied to the mask sheet can be adjusted while the mask sheet is stretched, and the adjusted tension can be maintained. 6. The screen printing apparatus according to any one of 5.