JPH11240129A - Screen printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To register a pattern on a screen with a base with high precision by adjusting a tensile strength using a second positioning device and adjusting a relative position between the base and the screen using a first positioning device. SOLUTION: A registering mark 1A for the position of a first screen is provided on a screen 1 and a registering mark 3A for a base 3 is provided on the base 3. Further, a pattern 2 is formed on the screen 1 and the screen registering mark 1A and the base registering mark 3A are superposed over each other. The amount of a shift between the marks 1A, 3A is read using a CCD camera 60 and the reading is calculated by a processor. In addition, the screen 1 is pulled to the outside by an actuator 40 installed, and a signal is output to a first positioning unit 20 for moving the base 3 in the X, Y, θdirections to correct the position. Consequently, it is possible to correct a pattern dimension and a pattern shape shown on the screen 1, so that the registering operation can be performed with high precision, even when the elongation of the screen 1 and the shrinkage of the base 3 occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a screen printing apparatus, and more particularly to a structure of a screen printing apparatus for positioning a pattern formed on a screen and a substrate with high accuracy.

[0002]

2. Description of the Related Art When a conductive pattern is formed on a printed circuit board or when a solder paste is partially applied, or when electrodes or the like are formed on a flat display glass substrate. In some cases, a screen printing device is used.

Here, when the above-described pattern is printed on a printed circuit board, a flat display, or the like using a screen printing apparatus, the printing accuracy is improved as the printed circuit board and the flat display become more precise and denser. There is a strong demand.

[0004] However, the screen currently used in the screen printing apparatus has a sheet in which fine wires are woven in a mesh shape is fixed to a frame, and a squeegee moves in contact with the screen during printing. Therefore, the squeegee exerts a force to extend the screen during printing, and the screen extends when printing is performed many times. As a result, the pattern drawn on the screen is deformed, and the alignment between the pattern and the substrate becomes inaccurate, which causes printing of a defective pattern.

On the other hand, the substrate itself expands and contracts by heating and the like in other manufacturing steps. For this reason, even if the pattern drawn on the screen is accurate, it is not possible to accurately align the pattern with the substrate.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problem, and a screen printing apparatus capable of performing high-accuracy alignment between a pattern drawn on a screen and a substrate. To provide.

[0007]

In order to achieve the above object, a screen printing apparatus according to the present invention comprises:
A screen having a pattern held by a screen holding member, and a squeegee moving on the screen, by a screen printing apparatus that prints the pattern using ink on a substrate supported by the substrate holding member and in contact with the screen below the screen. I do.

In such a screen printing apparatus,
Further, the following configuration is provided. In order to perform the alignment between the screen and the substrate, a first screen alignment mark and a substrate alignment mark provided on the screen and the substrate, respectively, and the screen and the substrate are relatively X, Y, and θ. A first positioning device for moving the screen, and a screen provided on the screen holding member, wherein the screen is elastically elongated by applying a tensile force to at least a part of a peripheral edge of the screen, so that the screen can be elastically extended. A second positioning device for performing positioning, a position deviation detecting device for detecting a position deviation between the first screen positioning mark and the substrate positioning mark, and a position deviation detecting device obtained from the position deviation detecting device. Adjusting the pulling force using the second positioning device based on the information, and 1
A control device is provided for adjusting the relative position between the substrate and the screen using a positioning device to minimize the amount of displacement between the substrate and the screen.

By adopting the above configuration, for example, a pattern drawn in advance on the screen is elastically stretched in the X and Y directions using the second positioning device, and the pattern is set to a predetermined size. Along with
By finely adjusting the relative position between the substrate and the screen using the first positioning device, it is possible to position the pattern provided on the screen and the substrate with extremely high precision.

In order to more specifically realize the above configuration, it is desired to employ the following configuration.

A plurality of the substrate alignment marks are provided inside the substrate, and a first screen alignment mark is provided on the screen at a position corresponding to the substrate alignment mark.

A plurality of second screen alignment marks are provided on the screen at positions corresponding to the outside of the substrate, and a substrate holding member alignment mark corresponding to the second screen alignment mark is provided on the substrate holding member. have.

Further, the first positioning device is provided on the substrate holding section. Further, the first positioning device is provided in the screen holding unit.

The first positioning device is provided in both the screen holding unit and the substrate holding unit.

Further, the second positioning device is provided with an engaging hole provided on a peripheral edge of the screen and an engaging member engaging with the engaging hole, and the screen is detached through the engaging hole. And a plurality of actuators that pull in a direction.

Further, the apparatus further comprises a vacuum suction device attached to the screen holding member and fixing the screen by vacuum suction at a peripheral portion of the screen.

The screen is a thin metal plate, and the above-mentioned pattern is formed in this thin plate by predetermined holes.

The screen is a plastic film or a thin plate, and the pattern is formed in the thin plate by predetermined holes.

Further, the apparatus for detecting the amount of misalignment comprises X, Y
A CCD camera movable in the direction, the CCD camera being provided above the screen.

A work station for exchanging, detaching, transporting, and the like the substrate and the screen, and a printing station for printing on the substrate are provided, and the displacement amount detecting device moves in the X and Y directions. It includes a plurality of possible CCD cameras, which are provided at least above the working station and the printing station.

Preferably, the work station includes an entrance station disposed on an entrance side of the printing station, and an exit station disposed on an exit side of the printing station.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a screen printing apparatus according to the present invention will be described below with reference to the drawings.

First, with reference to FIGS. 1A and 1B, the principle of alignment between a pattern provided on a screen used in a screen printing apparatus according to the present embodiment and a substrate will be described. FIG. 1A shows a normal state, and FIG. 1B shows a case where a tensile force (F) is applied to the outer peripheral edge of the screen.

Referring to FIG. 1A, a pattern 2 having a predetermined size and shape is formed on a screen 1. A plurality of first screen alignment marks 1A are provided at predetermined positions on the outer peripheral portion of the pattern 2 of the screen 1. The pattern 2 is drawn smaller than the dimension actually printed on the substrate. The substrate 3 has the first
A substrate alignment mark 3A is provided at a position corresponding to the screen alignment mark 1A.

Next, referring to FIG. 1B, the center of the first screen alignment mark 1A provided on the screen 1 and the center of the substrate alignment mark 3A provided on the substrate 3 coincide with each other. Then, a tensile force (F) is applied to the peripheral portion of the screen 1.

The tensile force (F) applied to the peripheral edge of the screen 1 does not necessarily need to be uniform, but rather, as shown by the length of the arrow in FIG. By making the power different, the screen 1
The positioning of the pattern 2 provided on the substrate 3 and the substrate 3 can be performed with higher accuracy.

The screen 1 is expanded and contracted by applying a tensile force (F) in the S direction (diagonal direction of the screen 1) in FIG. Positioning can also be performed.

By positioning the screen 1 and the substrate 3 in this manner, the pattern 2 and the substrate 3 can be positioned with high accuracy even when the screen 1 is elongated and the substrate 3 is deformed. Will be possible.

Next, the structure of the screen printing apparatus 1000 for realizing highly accurate positioning between the pattern 2 of the screen 1 and the substrate 3 will be described with reference to FIGS. FIG. 2 shows the screen printing device 1
FIG. 3 is a plan view of the screen printing apparatus 1.
FIG.

Referring to both drawings, this screen printing apparatus 1000 has a printing station 100 and a work station 200 in which the substrate 3, the screen 1 are replaced, detached, transported, and the like.

In the figure, the printing station 1
The work station 200 is provided on one side of the print station 10.
It is also possible to provide a work station 200 on both sides of 0 and one as an entry station and the other as an exit station.

The printing station 100 has a substrate holder 30 for holding the substrate 3 and a screen 1
A first positioning unit 20 as a first positioning device for moving in the X, Y, and θ directions and an elevating unit 16 for moving the substrate 3 toward or away from the screen 1 to form a printing station. 100
It is supported on the rail 12 so as to be able to reciprocate between and the entrance station 200. The rail 12
Is mounted on the frame 10 so as to maintain the horizontal position.

The work station 200 is provided with a CCD camera 60 for detecting the first screen alignment mark 1A provided on the screen 1 and the substrate alignment mark 3A provided on the substrate 3. Note that C
The CD camera 60 has a mechanism for moving in the XY directions (not shown).

Next, the structure of the printing section in the area surrounded by E in FIG. 3 will be described in detail with reference to FIG.

In the printing section, the substrate 3 is
0, the substrate 3 is fixed at a predetermined position by suction.
It is held at a position in contact with the screen 1 from below. The screen 1 is provided with a tensile force outward at the peripheral edge thereof by an actuator 40 as a second positioning device. This actuator 4
0 is fixed to the screen holder 42 as described later.

The screen 1 has a screen 1
Are provided with a plurality of vacuum suction devices 44 for vacuum-sucking the peripheral portion. Further, the screen holder 42 is provided with a squeegee base running rail 56,
A squeegee base 52 holding the squeegee 50 is held so as to be able to reciprocate in the direction of arrow A in the figure. Squeegee 5
The movement of 0 causes the ink 4 on the screen 1 to move.
Is printed on the substrate 3.

Next, the arrangement of the actuator 40 will be described with reference to FIG.
This will be described with reference to FIG.

A plurality of actuators 40 are provided on the screen holder 42 along the outer peripheral edge of the screen 1. The actuator 40 is provided with a hook 40a. The hook 40a engages with an engaging hole 1a provided on the outer peripheral edge of the screen 1 so that a predetermined tensile force can be applied to the screen 1. Has become.

The actuator 40 may be an air cylinder using a positive pressure, a bellows or a diaphragm using a negative pressure, or an electromagnet. Further, it is also possible to adopt a configuration in which a tension is applied by a screw and a motor via a spring.

Next, the state in which the hook 40a is engaged with the engagement hole 1a will be described in more detail with reference to FIGS. In the state shown in FIG. 6, the hook 40a is
3A shows a state in which a tensile force is applied using the actuator 40 in the direction shown by the arrow.

FIG. 7 shows a state in which the tensile force applied to the screen 1 is released, and the hook 40
The figure shows that a has been moved by the actuator 40 in the direction indicated by the arrow in the figure.

FIG. 8 shows a state in which the screen 1 is separated from the hook 40a. FIG. 9 illustrates a state in which the state illustrated in FIG. 7 is viewed from below.

Next, referring to FIG.
The structure of the first positioning unit 20 for moving the screen in the X, Y, and θ directions with respect to the screen 1 will be described. FIG. 10 is a plan view of the first positioning unit 20 as viewed from above.

A ball screw unit 71a for moving the substrate holder 30 in the X direction and ball screw units 71b and 71c for moving the substrate holder 30 in the Y direction are provided between the reference base 20A and the substrate holder 30. Is provided. Further, spring units 70a, 70b, 70c are provided between the reference base 20A and the substrate holder 30.
Is provided.

The ball screw units 71a, 71b, 71
c has a motor 72 and a ball screw 73, respectively, and drives the motor 72 to rotate the ball screw 73, thereby positioning the substrate holder 30 in the X, Y, and θ directions with high accuracy. Is possible. It should be noted that the reference base 20A is the lifting unit 16 shown in FIG.
It is supported by.

Next, with reference to FIGS. 11 to 13, a printing procedure using the above-described screen printing apparatus 1000 and a principle of alignment between the screen 1 and the substrate 3 will be described.

The screen 1 is provided with a circular hole as the first screen alignment mark 1A, and the substrate 3 is provided with a substrate alignment mark formed of a circular hole smaller than the first screen alignment mark 1A. 3A is provided. Further, a pattern 2 having a predetermined shape is formed in a central portion of the screen 1.

Step 1 First, as shown in FIG. 11, in the work station 200, the substrate 3 is brought into contact with the positioning pins 30a of the substrate holder 30, and the substrate 3 is suction-held at a predetermined position of the substrate holder 30.

Step 2 Next, as shown in FIG. 12, the substrate holder 30 holding the substrate 3 is moved from the work station 200 to the printing station 100. In the printing station 100, the screen positioning mark 1A and the substrate positioning mark 3A are in an overlapping state.

Step 3 Next, the substrate holder 30 is raised using the lifting unit 16 to bring the screen 1 into contact with the substrate 3. afterwards,
The ink 4 is applied to the entire surface of the screen using the squeegee 50, and the pattern 2 of the screen 1 and the first screen alignment mark 1A are printed on the substrate 3.

Step 4 Next, as shown in FIG. 13, after the screen printing is completed, the substrate holder 30 is lowered, and the substrate holder 30 holding the substrate 3 is moved from the printing station 100 to the work station 200.

Next, positioning of the screen 1 and the substrate 3 will be described. FIG. 13 shows a state of the substrate 3 on which the first screen alignment mark 1A of the screen 1 is printed.
(A) and (b). A circular first screen alignment mark 1A is printed around the substrate alignment mark 3A of the substrate 3.

As shown in FIG. 13B, the screen 1
When the positioning between the substrate and the substrate 3 is accurately performed, the first
The centers of the screen alignment mark 1A and the substrate alignment mark 3A coincide. On the other hand, screen 1 and substrate 3
If the positioning is not performed correctly,
As shown in (a), the first screen alignment mark 1A
And the center of the substrate alignment mark 3A.

This first screen alignment mark 1A
The amount of deviation between the substrate alignment mark 3A and the CCD camera 6
0, read by a dedicated processor, and output a predetermined signal to the actuator 40 and the first positioning unit 20 to correct the state shown in FIG.

The operations shown in FIGS. 11 to 13 are repeated one or more times to align the first screen alignment mark 1A and the substrate alignment mark 3A, and a range in which the amount of displacement between the two is allowable. If the value of
Performs continuous printing.

In this case, every time printing is performed, the CCD camera 6
With 0, the amount of displacement between the first screen alignment mark 1A and the substrate alignment mark 3A may be checked, or the amount of displacement may be checked every predetermined number of times.

If the amount of deviation is out of the allowable range, the arithmetic processing is performed by the dedicated processor as described above, and the same correction as described above is performed.

As described above, according to the screen printing apparatus according to the present invention, the pattern size and shape drawn on the screen can be corrected. It is possible to perform the positioning of both with high accuracy.

A second screen alignment mark having the same shape as the first screen alignment mark 1A is provided on the screen 1 outside the outer periphery of the substrate 3, and the substrate holder 30 is provided with the second screen alignment mark. A substrate holder alignment mark is provided at a corresponding position, and a first positioning device and a CC
By providing a D camera, the second screen alignment mark provided on the screen 1 and the substrate holder 3
0 and a substrate holder alignment mark provided beforehand, and a second
If the screen alignment mark is located at a relatively constant position, it is possible to reduce the number of alignment operations between the screen 1 and the substrate 3. in this case,
It is desirable that the second screen alignment mark is outside the traveling range of the squeegee 50. This is to prevent the second screen alignment mark from being stained with ink.

Further, after the screen correcting operation is completed, unnecessary deformation of the screen can be prevented by fixing the peripheral edge of the screen 1 using the vacuum suction device 44 provided on the screen holding member 42. .

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0062]

According to the screen printing apparatus of the present invention, the pattern drawn on the screen in advance is elastically stretched in the X and Y directions by using the second positioning device so that the pattern has a predetermined size. And by finely adjusting the relative position between the substrate and the screen using the first positioning device, it is possible to perform the positioning between the pattern provided on the screen and the substrate with extremely high precision. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an operation principle of a screen printing apparatus based on the present invention.

FIG. 2 is a plan view of a screen printing apparatus according to the present invention.

FIG. 3 is a front view of the screen printing apparatus according to the present invention.

FIG. 4 is an enlarged view of a region surrounded by E in FIG.

FIG. 5 is a view taken along the line FF ′ in FIG. 4;

FIG. 6 is a first diagram for explaining an operation state of the actuator 40;

FIG. 7 is a second diagram illustrating an operation state of the actuator 40.

FIG. 8 is a third diagram illustrating an operation state of the actuator 40.

FIG. 9 is a top view of the actuator 40 in the state shown in FIG. 7;

10 is a plan view of the first positioning unit 20. FIG.

FIG. 11 is a first diagram for explaining a printing procedure and a principle of alignment of the screen printing apparatus according to the present invention.

FIG. 12 is a second diagram for describing the printing procedure and the principle of alignment of the screen printing apparatus according to the present invention.

FIG. 13 is a third diagram for explaining the printing procedure and the principle of positioning of the screen printing apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 screen 1a engagement hole 1A first screen alignment mark 2 pattern 3 substrate 3A substrate alignment mark 4 ink 10 frame 12 rail 14 base 16 elevating unit 20 first positioning unit 30 substrate holder 30a positioning pin 40 actuator 40a hook 42 screen Holder 44 Vacuum suction device 50 Squeegee 52 Squeegee base 56 Squeegee base running rail 60 CCD camera 70a, 70b, 70c Spring unit 71a, 71b, 71c Ball screw unit 72 Motor 73 Ball screw 100 Printing station 200 Work station 1000 Screen printing device

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[Procedure amendment]

[Submission date] March 3, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 11

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 12

[Correction method] Change

[Correction contents]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

A work station is provided on one or both sides of a printing station for printing on the substrate, for exchanging, attaching and detaching and transporting the substrate and the screen.
The work station includes at least one CCD camera movable in X and Y directions, and the CCD camera is provided in the work station.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

A work station for exchanging, detaching and transporting the substrate and the screen and a printing station for printing on the substrate are provided, and the displacement detecting means moves in the X and Y directions. It includes at least one possible CCD camera, which CCD camera is provided at least in the work station and the printing station.

Claims (13)

[Claims] 1. A screen for printing the pattern using ink on a substrate supported by a substrate holding member and in contact with the screen below the screen, the screen being held by a screen holding member and having a pattern, and a squeegee moving on the screen. A printing apparatus, comprising: a first screen alignment mark and a substrate alignment mark provided on the screen and the substrate, respectively, for performing alignment between the screen and the substrate; A first positioning means for moving the screen in the X, Y, and θ directions; and a tensile force applied to at least a part of a peripheral edge of the screen to elastically expand the screen. And positioning the screen with respect to the substrate. Based on information obtained from the position shift amount detecting means for detecting a position shift amount between the first screen alignment mark and the substrate position alignment mark; Adjusting the pulling force using the second positioning means, and
Control means for adjusting the relative position between the substrate and the screen using the first positioning means to minimize the amount of misalignment between the substrate and the screen;
A screen printing device having: 2. The apparatus according to claim 1, wherein a plurality of the substrate alignment marks are provided inside the substrate, and the first screen alignment mark is provided on the screen at a position corresponding to the substrate alignment mark. Screen printing device. 3. A plurality of second screen alignment marks are provided at positions on the screen corresponding to the outside of the substrate, and the substrate holding member is aligned at a position corresponding to the second screen alignment mark on the substrate holding member. 3. The screen printing apparatus according to claim 1, wherein a plurality of marks are provided. 4. The screen printing apparatus according to claim 1, wherein said first positioning means is provided on said substrate holding member. 5. The screen printing apparatus according to claim 1, wherein the first positioning unit is provided on the screen holding member. 6. The first positioning means is provided on both the substrate holding member and the screen holding member.
The screen printing device according to claim 1. 7. The second positioning means includes: an engagement hole provided in a peripheral edge of the screen; and an engagement member engaged with the engagement hole. The screen printing apparatus according to any one of claims 1 to 6, further comprising: a plurality of actuators that pull in a direction. 8. The image display device is attached to the screen holding member,
The screen printing apparatus according to any one of claims 1 to 7, further comprising vacuum suction means for vacuum-adhering a peripheral portion of the screen to fix the screen. 9. The screen is a thin metal plate,
The screen printing apparatus according to any one of claims 1 to 8, wherein the pattern is formed in the thin plate by predetermined holes. 10. The screen according to claim 1, wherein the screen is a plastic film or a plastic thin plate, and the pattern is formed in the film or the thin plate by predetermined holes. Screen printing device. 11. The apparatus according to claim 1, wherein said displacement amount detecting means includes a CCD camera movable in X and Y directions, wherein said CCD camera is provided above said screen.
0. The screen printing device according to any one of 0. 12. A work station in which the substrate and the screen are exchanged, detached, transported, and the like, and a printing station in which printing is performed on the substrate are provided. The displacement amount detecting means moves in the X and Y directions. Possible C
The screen printing apparatus according to claim 1, further comprising a plurality of CD cameras, wherein the CCD cameras are provided at least above the work station and the printing station. 13. The screen printing apparatus according to claim 12, wherein the work station includes: an entrance station disposed on an entrance side of the printing station; and an exit station disposed on an exit side of the printing station. .