JP2001356485A - Exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problem in the conventional exposure device of a semi- automatic system, that an exposure defect by dust occurs easily, the tact time is long, the structure is intricate, and the cost is high. SOLUTION: This exposure device is provided with a mask holding mechanism 5 which holds an exposure mask 56 in a perpendicular posture, a work holding mechanism 3 which has two work holding surfaces 21a for freely attachably and detachably holding a plate (w) to be exposed and rotates the anther one work holding surface 21a 180 deg. around the axis so as to come to a work attaching and detaching position facing the outside of a machine casing 11 in a forward downwardly inclining posture when the one work holding surface 21a comes to the exposure position parallel facing the exposure mask 56 and an alignment mechanism 7 which aligns the reference to the exposure mask 56 in contact with the plate (w) to be exposed coming to the exposure position. Then, the attachment and detachment of the another plate (w) to be exposed can be progressed while the one plate (w) to be exposed is subjected to alignment and exposure and therefore, the tact time is shortened and there is no possibility that the accuracy of the alignment goes wrong, and the pickup of the dust to the exposure mask 56 is substantially prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an exposure apparatus. More specifically, the present invention relates to an exposure apparatus that exposes an exposed surface of a plate to be exposed such as a printed circuit board or a lead frame material through an exposure mask on which a required exposure pattern is formed.

[0002]

2. Description of the Related Art For example, an exposure apparatus used for forming a pattern on a printed circuit board is roughly classified into a manual type which manually attaches / detaches a plate to be exposed and aligns (reference position) with an exposure mask by hand. There are a semi-automatic type in which only the plate to be exposed is attached and detached manually, and a fully automatic type in which all of them are mechanically performed. The manual type cannot be used for high-density printed wiring boards because of poor alignment accuracy, and the fully automatic type has a remarkably high cost. Therefore, the semi-automatic type is often used today.

FIG. 5 shows an example a of a conventional semi-automatic exposure apparatus. In the figure, b denotes a film exposure mask provided in a horizontal posture, an exposure lamp c is provided downward above the exposure mask b, and an alignment camera g is provided. Exposure mask b
Is located below the vertical alignment table (X, Y, θ).
Table) d. e indicates a work holding table. This work holding table e is horizontally moved with the work holding surface f on which the plate to be exposed w is detachably held facing upward, and the movement is opposed to the exposure mask b from below as shown by the solid line. The exposure is performed between the exposure position and the work attachment / detachment position indicated by a two-dot chain line.

The plate w to be exposed is sucked and held on the work holding table e with its exposed surface facing upward. When the work holding table e in this state is moved to the exposure position, the alignment table d rises. Combine with the work holding table e. Then, the amount of displacement between the exposure mask b and the plate to be exposed w is detected by the camera g and the detection circuit, and correction according to the amount of displacement is performed by the alignment table d. That is, reference positioning is performed. Then
The exposure mask b is attracted to the plate w to be exposed, and in this state, the exposure lamp c emits light to perform exposure using the exposure pattern of the exposure mask b. When the exposure is completed, the work holding table e is pulled out to the work attaching / detaching position.

[0005]

In the semi-automatic exposure apparatus a, the alignment accuracy is high, unlike the manual alignment apparatus using the positioning pins, and the plate w to be exposed is exposed. Since the alignment is performed in the state where the position has been reached, there is an advantage that the aligned state is not disturbed. However, since the plate to be exposed w and the exposure mask b are always kept in a horizontal position, dust is inevitably attached, and there is a problem that an exposure error easily occurs due to the dust.

Further, according to this structure, since there is only one work holding table e, the work for the next exposure during the exposure, that is, the exposed plate w is removed and the next plate Since the work of mounting w and cleaning it with a dust removal roller cannot be performed in parallel, there is a practically serious drawback that the so-called tact time becomes very long and the processing efficiency does not increase.

[0007] Regarding the problem of the tact time, two work holding tables each having an exposure mask are arranged in upper and lower two stages and moved alternately, and the work holding table is at the work attaching / detaching position. A structure has been proposed in which the alignment is completed and then moved to the exposure position. However, in the case of this structure, the exposure mask must be opened and closed and the alignment camera must be released to the side each time the work is attached and detached, so that the tact time is not so reduced. In addition, the accuracy of the alignment may be degraded due to the movement of the work holding table after the alignment, and there is a problem that the cost is considerably increased due to the extremely complicated structure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and the tact time can be greatly reduced without increasing the number of exposure masks and work holding tables. Alignment can be performed and there is no danger that the alignment accuracy will go wrong.
An object of the present invention is to provide a novel exposure apparatus that can make it difficult for dust to adhere to an exposure mask.

[0009]

In order to achieve the above object, an exposure apparatus according to the present invention comprises: an exposure apparatus which holds an exposure mask in a vertical position and contacts an exposed plate coming to an exposure position; A mask holding mechanism provided in the housing so as to move between a retreat position and a work holding surface for detachably holding a plate to be exposed, wherein one work holding surface is the exposure mask A work holding mechanism which is rotated so that another work holding surface comes to a work attaching / detaching position facing the outside of the machine when the exposure position comes parallel to the exposure position; And an alignment mechanism for performing reference alignment with the exposure mask.

Therefore, according to this exposure apparatus, while alignment and exposure are being performed on the plate to be exposed held on one work holding surface, the exposure on another work holding surface that is at the work attaching / detaching position is performed. Since the removal and mounting of the exposure plate can be performed simultaneously, there is almost no waiting time, and the tact time can be greatly reduced as compared with the conventional exposure apparatus a. Moreover, unlike a conventional exposure apparatus in which a work holding table is held in two stages and moved individually, only one work holding mechanism is required, and there is no need to provide an exposure mask for each work holding surface. Can be mounted on a mask holding mechanism. Therefore, since the structure is not complicated, there is no danger of an increase in cost, and there is no trouble in attaching and detaching the plate to be exposed to and from the work holding mechanism.

Further, since the plurality of work holding surfaces are moved between the exposure position and the work attachment / detachment position in accordance with the change in posture due to the rotational movement of the work holding mechanism, a method of linearly reciprocating between these two positions is adopted. In comparison, only a small space is required for movement, and the position can be changed at a high speed, which also contributes to a reduction in tact time. Since the alignment is performed in a state where the plate to be exposed is at the exposure position, there is no possibility that the accuracy of the already-executed alignment is disturbed. In addition, since the exposure mask is always placed in a vertical position, it is possible to effectively prevent dust from adhering to the exposure mask, thereby considerably preventing the occurrence of exposure errors.

An exposure apparatus according to a second aspect of the present invention provides an exposure apparatus according to the first aspect.
In the exposure apparatus described in (1), the work holding surface that has come to the attachment / detachment position has a horizontal or downwardly inclined posture.

With this arrangement, various operations such as attaching and detaching the plate to be exposed to and from the work holding mechanism and cleaning the mounted plate to be exposed with the roller can be performed with respect to the work holding surface having a horizontal posture or a forwardly inclined posture. So that
When the present invention is of a semi-automatic type, such operations can be performed easily, and work efficiency can be improved. In carrying out the present invention, the center axis of rotation of the work holding mechanism is required to be inclined with respect to the vertical, so that the rear side required when the work holding mechanism rotates is required. The maximum distance seen on the vertical projection plane of the space is considerably smaller than the maximum distance seen on the vertical projection plane of the rear space required when rotating a work holding mechanism of the same width about the vertical axis as the center of rotation. Accordingly, the distance by which the mask holding mechanism should be separated from the work holding mechanism when the work holding mechanism rotates can be shortened. This also contributes to shortening of the tact time.

According to the third aspect of the present invention, there is provided an exposure apparatus according to the first aspect.
Or the work holding mechanism includes two work holding surfaces, and is provided so as to rotate around an axis passing through an intermediate position between the two work holding surfaces, and the work holding mechanism includes one work holding surface. A central angle of about 180 ° is rotated between a first position at which the surface comes to the exposure position and a second position at which another work holding surface comes to the exposure position. With this configuration, the moving distance of the work holding surface can be minimized, and the piping process of the intake path incorporated in the work holding mechanism can be simplified.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a semi-automatic exposure apparatus 1 will be described below with reference to the drawings. [A. Structure] The exposure apparatus 1 includes a work holding mechanism 3 for detachably holding a plate w to be exposed, a mask holding mechanism 5 for holding an exposure mask, an alignment mechanism 7 mounted on the mask holding mechanism 5, It is composed of an exposure lamp 9 and the like.

[A-1. Work holding mechanism] (FIGS. 1 to 4) The work holding mechanism 3 is arranged at the front end of the machine case 11 (only part of which is shown in FIG. 2), and a part thereof is provided on the front wall of the machine case 11. The mask holding mechanism 5 faces the work holding mechanism 3 from behind.

The work holding mechanism 3 has a rotating shaft 15 rotatably supported by a machine base 13, and a hollow casing 16 is mounted on the rotating shaft 15. The casing 16 has a substantially equilateral triangular shape with a skirt extending when viewed from the left and right, and has a rectangular horizontal cross section. An intermediate portion between a boss portion 17a and a top portion 18 formed at the center of the bottom wall 17 is formed. It is fixed to the rotating shaft 15. Casing 16
The front and rear side walls are a work holding base 20 for detachably holding the plate to be exposed w. Therefore, these work holding bases 20 are at the same angle α with respect to the rotation axis 15.
(See FIG. 3) and the angle α is approximately 30 °.

The work holding base 20 is formed in a rectangular flat plate shape, and a portion 21 excluding the outer peripheral portion is formed to be thick because the surface facing the outside of the casing 16 projects slightly from the other portions. The top surface of the thick portion 21 is a work holding surface 21a. A rubber airtight holding wall 22 extending endlessly is attached to the outer peripheral portion of the work holding base 20 so as to surround the thick portion 21 at a certain distance from the thick portion 21. And this work holding base 20
Has a large number of intake holes 23 opened in the work holding surface 21a.
In addition, another intake hole 24 is formed in a region between the thick portion 21 and the airtight holding wall 22.

At the front end of the machine base 13, a bearing block 31 having a ball bearing is mounted. The bearing block 31 is provided so that its axis is inclined backward by 30 ° with respect to the vertical, and the lower part of the rotating shaft 15 is rotatably supported by the bearing block 31.

Therefore, the two work holding surfaces 21a of the work holding base 20 are in a vertical posture when they come to the rear of the rotary shaft 15 and face rearward, and when they come to the front of the rotary shaft 15, they move forward. It is inclined 30 ° downward, and faces upward and diagonally forward. The position of the work holding surface 21a when it comes to the rear side of the rotating shaft 15 is the "exposure position", and the position of the work holding surface 21a when it comes to the front side of the rotating shaft 15 is the "work attaching / detaching position". When one work holding surface 21a is at the exposure position, another work holding surface 21a is at the work attaching / detaching position. The work holding surface 21a that has come to the work attachment / detachment position is a work attachment / detachment opening 1 formed in the machine housing 11.
Face 1a.

A timing pulley 33 is fixed to the rotating shaft 15, and a stepping motor 3 is provided beside the rotating shaft 15.
A backlashless type timing belt 36 is stretched between a timing pulley 35 attached to an output shaft of the stepping motor 34 and a timing pulley 33 of the rotary shaft 15.
Accordingly, the rotation shaft 15 is pitch-rotated by the stepping motor 34, and the rotation is performed at a first position where one work holding surface 21a comes to the exposure position and a second position where another work holding surface 21a comes to the exposure position. It is controlled so as to reciprocate at a central angle of 180 ° between the two positions. Each of these positions is locked by a disk brake mechanism 38 including a disk 37 fixed to the rotating shaft 15.

The rotating shaft 15 has a hollow pipe shape.
Although not shown, an intake hose extending from the vacuum device passes through the lower end of the rotary shaft 15 and is led out of the upper hole 15a into the casing 16 through the rotary shaft 15. Are connected to suction nozzles attached to the suction holes 23 and 24 of the work holding base 20. Therefore, when the suction path following the suction hole 23 becomes negative pressure, the work holding surface 21a becomes negative pressure,
Due to this negative pressure, the plate w to be exposed is suction-held on the work holding surface 21a as shown in FIG. In addition, when the suction path following the suction hole 24 becomes negative pressure, the work holding surface 21
A negative pressure is generated around the area a, and the negative pressure causes an exposure mask to be described later to come into close contact with the plate w to be exposed.

[A-2. Mask Holding Mechanism] (FIGS. 1, 2, and 4) The mask holding mechanism 5 is provided on a guide rail 41 attached to the machine base 13 so as to be movable in the front-rear direction.
That is, the mask holding mechanism 5 includes a slide base 51 which is substantially L-shaped when viewed from the side, and a leg 52 fixed to the lower surface of the bottom of the slide base 51 is slidably engaged with the guide rail 41. By being combined, they are provided so as to be movable within a certain range in the front-rear direction. Slide base 5
A large rectangular window 54 is formed in one vertical wall 53, and mask frame support members 55 are attached to upper and lower ends of the front surface of the vertical wall 53.

Reference numeral 56 denotes an exposure mask. The exposure mask 56 is slightly larger than the plate w to be exposed, and its outer peripheral portion is held by a rectangular mask frame 57.
7 is supported by the mask frame support member 55 so as to be able to move to some extent in a vertical plane. Therefore, the window 54 of the slide base 51 is substantially closed from the front by the exposure mask 56. The mask frame 57 has a hollow structure, and the front surface of the mask frame 57 is set to a negative pressure by a suction unit (not shown) connected thereto. The negative pressure holds the exposure mask 56.

[A-3. Alignment Mechanism, Exposure Lamp] (FIGS. 1 and 2) The slide base 51 of the mask holding mechanism 5 is provided with three pulse motors 61. Two of the three pulse motors 61 are mounted on the front surface of the lower end of the slide base 51 so as to be separated from each other in the left-right direction, and the other pulse motor 61 is mounted on the front surface of the side end of the slide base. The reach shafts of these pass motors 61 are connected to the mask frame 57. Accordingly, by driving one or a plurality of these pulse motors 61 at the same time, the mask frame 57 is moved up and down, in the direction, left and right directions, or rotated in a vertical plane.

The slide base 51 includes a camera 63.
Are mounted on the left and right. These cameras 63 are so-called CCD cameras provided with a fixed image pickup device. A bracket 64 protrudes rearward from both left and right sides of the vertical wall 53 of the slide base 51, and a camera moving mechanism 65 is attached to the bracket 64, and the camera 63 is moved forward by the camera moving mechanism 65. It is mounted in a facing position. Then, when performing alignment, the camera 63 moves to a detection position (FIG. 1 shows a state in which the photomask mark (not shown) provided on the exposure mask 56 is aimed at from the rear). And
When exposure is performed, the exposure mask 56 is moved to a standby position where it has escaped sideways from behind. The pulse motor 61 and the camera 63 constitute the alignment mechanism 7.

The exposure lamp 9 is arranged behind the mask holding mechanism 5, and the light emitted from the exposure lamp is
It goes forward through the light transmission pattern of the exposure mask 56.
The exposure apparatus 1 is configured as described above, and the work holding surface 21a of the work holding mechanism 3 faces the exposure mask 56 in parallel when it comes to the exposure position.

[B. Method of Use and Operation] Next, a method of use and operation of the exposure apparatus 1 will be described. In the initial state,
The work holding mechanism 3 is locked at the first position or the second position, and the mask holding mechanism 5 is at a retracted position separated from the work holding mechanism 3 rearward as shown by a solid line in FIG. This separation distance is a distance slightly deviating from the rotation trajectory of the work holding mechanism 3 (in FIG. 1, for convenience of drawing, the Mc holding mechanism 5 is moved beyond the guide rail 41 for this drawing distance).
(Shown backward with). And camera 6
3 is at the detection position.

First, an unexposed plate w to be exposed is placed on the work holding surface 21a, which is now at the work attaching / detaching opening 11a, with its exposed surface facing up. The placed plate w to be exposed is suction-held there by the negative pressure of the work holding surface 21a. The operator cleans the exposed surface of the placed plate to be exposed w with a roller. When the reverse button of the control panel (not shown) is pressed, the lock by the disc brake 38 is released, and the stepping motor 34 is driven,
The work holding mechanism 3 is inverted. As a result, the workpiece holding surface 21a on which the plate to be exposed w is now moved to the exposure position, so that the plate to be exposed w is in a vertical posture and faces the exposure mask 56 in parallel. Exposure mask 5
The other work holding surface 21a opposed to 6 comes to the work attaching / detaching opening 11a in a posture of lowering forward.

When it is detected that the work holding mechanism 3 is reversed, the rotation of the stepping motor 34 is stopped, and the work holding mechanism 3 is actuated by the disc brake 38.
Is locked, and then the mask holding mechanism 5 moves to the forward position shown by the two-dot chain line in FIG. 2 to make the exposure mask 56 lightly contact (soft contact) the exposure target plate w. Here, the camera 63 photographs the photomask mark of the exposure mask 56 and the reference hole formed in the exposed plate w,
The detection circuit calculates the position shift according to the captured image,
Alignment mechanism 7 according to a command based on the content of this calculation
Is driven to set the positional deviation between the photomask mark and the reference hole within an allowable range.

When the alignment is completed in this manner, the suction hole 24 of the work holding base 20 becomes a negative pressure, and the exposure mask 56 is brought into close contact with the plate w to be exposed (see FIG. 4). Here, the exposure lamp 9 emits light to perform exposure, and when a time required for the exposure has elapsed, the negative pressure on the intake hole 24 is released, and then the mask holding mechanism 5 is returned to the retracted position.

On the other hand, while the movement, alignment, exposure and the like of the mask holding mechanism 5 are being performed in the machine housing 11 in this manner, the worker holds the work holding surface 21a coming to the work attaching / detaching opening 11a. The next plate to be exposed w is held, and cleaning and other necessary operations are performed. Then, the mask holding mechanism 5
Is turned on, that is, a lamp indicating that the exposure has been completed is turned on, the work holding mechanism 3 is inverted again. As a result, the exposed plate w is exposed to the work loading / unloading opening 11a.
And the unexposed plate w to be exposed is carried into the machine case 11 and faces the exposure mask 56.

The above-described series of processing (advance of the mask holding mechanism 5, alignment, exposure, and retreat of the mask holding mechanism 5) is performed on the plate to be exposed w carried into the casing 11, during which time work is performed. The operator removes the exposed plate w to be exposed, mounts the next plate to be exposed w, and performs cleaning or the like. The exposure of the plate to be exposed w is advanced by repeating such a cycle operation. Note that dust can be more completely removed by using a method of blowing ion air or the like as a method of cleaning the plate w to be exposed.

The embodiment of the present invention has been described above.
The specific configuration of the present invention is not limited to this embodiment, and any change in design or the like without departing from the spirit of the present invention is also included in the present invention. For example, in the embodiment, the work holding mechanism has two work holding surfaces.
It is also conceivable to have one.

Further, in the embodiment, the rotation axis of the work holding mechanism is inclined by 30 ° with respect to the vertical, but this inclination is not limited to 30 °, and the work coming into the work attaching / detaching position is not specified. If the holding surface may be in a vertical position, this axis may be set vertically. In the embodiment, the present invention is applied to a semi-automatic type.
The present invention can also be applied to an automatic exposure apparatus that automatically attaches and detaches a plate to be exposed to and from a work holding surface using a pickup mechanism or the like.

[0036]

As described above, according to the present invention, the waiting time is almost eliminated, the tact time can be greatly reduced, the work holding mechanism is basically required to be one, and the exposure mask can be used for the work. Since it is not necessary to provide for each holding surface,
The structure is not complicated, and there is no trouble in attaching and detaching the plate to be exposed to and from the work holding mechanism. Further, since the plurality of work holding surfaces are moved between the exposure position and the work attachment / detachment position in accordance with the change in the posture due to the rotation of the work holding mechanism, the work holding surface is moved back and forth linearly between the two positions.
Only a small space for movement is required, and the position can be changed at a high speed, which also contributes to a reduction in tact time. Since the alignment is performed in a state where the plate to be exposed is at the exposure position, there is no possibility that the accuracy of the already-executed alignment is disturbed. In addition, since the exposure mask is always placed in a vertical position, it is possible to effectively prevent dust from adhering to the exposure mask, thereby considerably preventing the occurrence of exposure errors.

According to the second aspect of the present invention, various operations such as attaching and detaching the plate to be exposed to and from the workpiece holding mechanism and cleaning the mounted plate to be exposed by the roller are performed in a horizontal posture or a posture inclined forward and downward. Since the operation is performed on the holding surface, when the present invention is made semi-automatic, such various operations can be easily performed, and the operation efficiency is improved. And
When the work holding mechanism rotates, the maximum distance seen from the vertical projection plane in the rear space required when rotating the work holding mechanism is short, and the distance that the mask holding mechanism should be separated from the work holding mechanism when the work holding mechanism rotates is small. It can be shortened, which also contributes to shortening of tact time.

According to the third aspect of the present invention, the moving distance of the work holding surface can be minimized, and the processing of the intake hose incorporated in the work holding mechanism can be simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of the exposure apparatus shown in FIG.

3 is an enlarged vertical sectional view of a work holding mechanism of the exposure apparatus shown in FIG.

4 is an enlarged sectional view of a main part showing a contact state between a plate to be exposed and an exposure mask by the exposure apparatus shown in FIG. 1;

FIG. 5 is a schematic view showing an example of a conventional semi-automatic exposure apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Exposure apparatus 3 ... Work holding mechanism 5 ... Mask holding mechanism 7 ... Alignment mechanism 11 ... Machine housing 15 ... Axis
21a: Work holding surface 56: Exposure mask w: Exposed plate

Claims (3)

[Claims] 1. A mask provided in a housing so as to move between an advanced position in contact with a plate to be exposed at an exposure position and a retracted position separated from the exposure plate while holding the exposure mask in a vertical position. A holding mechanism and a plurality of work holding surfaces for detachably holding the plate to be exposed are provided. When one work holding surface comes to an exposure position in parallel with the exposure mask, another work holding surface is provided outside the casing. A work holding mechanism that is rotated to come to a work attachment / detachment position facing the workpiece, and an alignment mechanism that performs a reference position alignment between the exposed plate that has come to the exposure position and the exposure mask that has come to the advance position. Exposure equipment. 2. The exposure apparatus according to claim 1, wherein the work holding surface at the attachment / detachment position is inclined horizontally or forward. 3. The exposure apparatus according to claim 1, wherein the work holding mechanism includes two work holding surfaces and rotates about an axis passing through an intermediate position between the two work holding surfaces. And a central angle of 180 turns between a first position where one work holding surface comes to the exposure position and a second position where another work holding surface comes to the exposure position. Exposure apparatus.