JPH0541982B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention improves efficiency by accurately aligning an image mask and a workpiece when simultaneously exposing images such as printed wiring on both sides of a workpiece such as a printed circuit board. The present invention relates to a double-sided automatic exposure device with alignment that can perform good exposure.

[Conventional technology]

In recent years, as the degree of integration of mounted components (especially integrated circuits) has improved, wiring patterns on printed circuit boards, etc. are required to have higher density and higher definition, and the positioning of the workpiece and image mask during exposure in photolithography also requires high precision. has become required.

To expose and print an image such as a predetermined wiring pattern on a workpiece such as a printed circuit board, the workpiece and an image mask are aligned, and then parallel light or the like is transmitted through the workpiece while the workpiece is in close or close contact with the workpiece. As a conventional technique regarding a device for aligning a workpiece and an image mask when simultaneously exposing both sides of a workpiece, the present applicant has disclosed in a patent application "Workpiece Alignment Device for Double-Sided Exposure" dated August 13, 1985. . The method of aligning the workpiece and the upper and lower image masks in double-sided exposure is to install an alignment stage outside the exposure section consisting of the upper and lower printing frames, align the workpiece on the alignment stage, and then remove the workpiece. The workpiece is transported to the exposure section using a transport means, and the exposure section checks and calculates the amount of positional deviation of the workpiece, and returns the workpiece to the alignment stage for realignment or reflects it in subsequent workpiece alignments. The purpose of this system was to increase workpiece throughput by performing workpiece alignment and exposure in an assembly-line process, and to simplify the workpiece alignment mechanism.

[Problem that the invention seeks to solve]

In the above-mentioned conventional alignment apparatus, the workpiece is aligned on an alignment stage outside the exposure section, and then transported and set at the exposure position of the exposure section by a conveyance means such as a handler or transfer. However, there is a problem that high accuracy cannot be expected because there is a risk that the position of the work may be misaligned during the operations of holding and transporting the work by this transport means and holding and releasing the work after reaching the exposure position.

Therefore, there is a risk that the workpiece position may be misaligned, so it is necessary to frequently check the workpiece position in the exposure section, and any misaligned workpieces must be returned to the alignment device for realignment or removed. This has become a problem in further improving production capacity.

The present invention was devised to solve the above problems, and an object of the present invention is to provide a double-sided automatic exposure device with alignment that is capable of highly accurate positioning of an image mask and a workpiece, and that can improve production efficiency. purpose.

[Means for solving problems]

As a means for achieving the above object of the present invention, there is provided a means for carrying in a workpiece having a positioning mark, an alignment section that holds and aligns the workpiece carried in by this carrying means, and a section directly below the alignment section. one baking frame on which the aligned workpiece is placed; a moving table that reciprocates this baking frame from the alignment position to the exposure position; the other baking frame waiting at the moving end of the moving table; An exposure unit that performs exposure by sandwiching a workpiece between one and the other printing frames, and a carrying unit that carries out the workpiece that has been exposed in this exposure unit,
The alignment section compares the positional information of the positioning mark of the workpiece with an imaging means that images the positional information of the positioning mark of the workpiece and sends it as a signal, and the sent positional information and reference data stored in advance to determine the amount of positional deviation of the positioning mark of the workpiece. It has a control unit that calculates and outputs it as a displacement signal, and an alignment table that holds and aligns the workpiece based on the signal from this control unit. A double-sided automatic exposure device with alignment having a holding means to prevent the exposure. ”.

[Effect]

In the present invention, one of the printing frames in the exposure section is moved to the alignment section using a moving table, and the workpiece, which is aligned with the image mask of one printing frame by the alignment section, is moved to the one printing frame by the work holding means. The workpiece is held directly in the frame, returned to the exposure section, and exposed on both sides between it and the other printing frame. Therefore, after positioning the workpiece, there is no need for the workpiece to be held, transported, or released from holding by the conveying means until the workpiece is held in one of the baking frames, so that the workpiece will not be mispositioned due to such actions.

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

FIG. 1 is a front view of an apparatus according to an embodiment of the present invention. First, the configuration of the exposure section will be described. The exposure section 1 is composed of one printing frame (hereinafter referred to as a lower printing frame) 2, the other printing frame (hereinafter referred to as an upper printing frame) 3, and irradiation optical systems 4a and 4b for double-sided exposure. A transparent acrylic plate 2a is fixed to the pre-baking frame 2, and a lower mask film 5 serving as one image mask is vacuum-adsorbed on its upper surface by a groove formed on the acrylic plate 2a. Similarly, a transparent acrylic plate 3a is fixed to the finishing frame 3, and a top mask film 6 is vacuum-adsorbed as the other image mask. The top baking frame 3 is supported by a guide shaft 7 and is configured to be movable up and down, so that the bottom baking frame 2 can be approached. An appropriate number of mask film alignment pins 8 are buried in the acrylic plate 2a of the pre-firing frame so that they can be projected onto the acrylic plate surface using an air cylinder or the like. The upper and lower mask films 5 and 6 are placed one on top of the other, and the respective alignment holes are inserted into the pins 8, and the acrylic plate 3a of the top baking frame is moved downward to approach and the top mask film 6 is adsorbed. Align the lower mask film. After this alignment, the pin 8 is buried under the surface of the acrylic plate 2a.

Next, the configuration of the moving table will be described. The movable table 9 holds the above-mentioned pre-baking frame 2, and the two rails 1
0 so as to be horizontally movable using an air cylinder or the like (not shown). Moving table 9 of exposure section 1
A stopper 11 is provided at the stop position of the moving table 9, and the moving table 9 is moved to this stopper 11 using the air cylinder or the like.
The structure is such that positioning can be performed with high precision by pressing. Similarly, a stopper 12 is provided on the alignment section side of the movable table 9, and the movable table 9 is pressed by the air cylinder or the like, so that the movable table 9 is accurately positioned directly below the alignment table.

Next, the configuration of the alignment section will be described. The alignment section 13 is disposed above the above-mentioned predetermined position,
The workpiece is held and aligned with the lower mask film, and the aligned workpiece is delivered to the pre-baking frame 2 which has been moved to a predetermined position. This alignment unit 13 includes an
a Y table 15 whose movement is controlled in the direction; a θ table 16 whose rotation is controlled by an angle of θ in the rotation direction;
It has an alignment table consisting of an acrylic plate 18 that holds the workpiece 17 by suction. Then, the alignment reference mark on the lower mask film 5 and the alignment mark on the workpiece 17 are read 2.
It is composed of a television camera 19 on a stand, a control unit that controls the position of each table, etc., and each table is moved up and down by a base 21 using a guide shaft 20.
is maintained. The details of the configuration of the above alignment section 13 are shown in FIGS. 2 and 3. FIG. 2 is a diagram showing the configuration of the alignment section 13 and the configuration of the control section viewed from the bottom, and FIG. 3 is a sectional view of the support members of each table. Each table is supported by a supporting member 22 on the upper table or base 21 so as to be slidable at key points.
First, the X table 14 is supported by a support member 22a on the base 21 so as to be slidable in the X direction.
On one side of the base 21 in the X direction, an X table pressing means 14a that moves forward and backward in the X direction by a specified amount by a pulse motor or the like is provided, and on the other side, an X table urging member 14b is provided. The X-table is arranged so as to urge the X-table in the retreating direction of the X-table pressing means 14a. With the above configuration, the X table is positioned and controlled in the X direction. The Y table 15 is supported by the X table 14 by a support member 22b so as to be slidable in the Y direction. One side of the X table 14 in the Y direction is provided with a Y table pressing means 15a that moves forward and backward in the Y direction by a specified amount by a pulse motor, etc., and the other side is provided with a Y table urging member 15b. is arranged so as to urge the Y table in the retreating direction of the Y table pressing means 15a. With the above configuration, the Y table is positioned and controlled in the Y direction. The θ table 16 is rotatably supported by the Y table 15 by a support member 22c. The Y table 15 is provided with a θ table pressing means 16a that moves forward and backward in the rotational direction of the θ table 16 by a specified amount by a pulse motor or the like, and this θ table pressing means 16a is fixed to the edge of the θ table 16. The protrusion piece 16b is moved forward and backward. This protruding piece 16b is urged by a θ table urging member 16c provided on the Y table 15 in the forward and backward direction of the pressing means 16a. With the above configuration, the rotation of the θ table is controlled by a designated angle θ in the rotation direction. In the above, the support members 22a and 22b for X and Y movement are formed with a V groove 22e that holds a ball bearing 22d in a straight line, and the support member 22c for rotation is formed with a V groove 22e that holds a ball bearing 22d.
e is formed into an arc shape. The acrylic plate 18 is attached to the θ table 16, and the workpiece 17 is inserted into the lattice-shaped grooves 1 arranged on the lower surface of the acrylic plate 18.
It is vacuum-adsorbed by 8a. Note that the support structure and moving mechanism of each table are not limited to those described above, and other moving mechanisms may be used, such as one using a screw rod and a nut, for example.

The control section 23 is connected to two television cameras 19 fixed to the base 21, and reads and stores two positioning reference marks on the lower mask film 5 that is first moved to a predetermined position in the alignment section 13. Thereafter, the alignment mark of the workpiece 17 held based on this memorized reference mark is read, the amount of deviation is calculated, and the X drive unit 24, Y drive unit 25, θ
Each pressing means 14a, 15a,
The specified movement amount and specified angle are given to 16a as the number of pulses. If there is an error between the alignment mark size of the workpiece 17 and the reference mark size, it is preferable to adjust the position by proportionally adjusting the error to each reference mark.

FIG. 4 is a longitudinal sectional view of an embodiment of a work holding means for receiving an aligned work from the alignment section 13 and holding it in the pre-baking frame 2. FIG. This work holding means 27 is the acrylic plate 2a of the pre-baking frame.
By the air cylinder 28 buried in the side part of
The lever 29 is made rotatable. A workpiece holding pawl 29a is formed at the tip of the lever 29, and holds the edge of the workpiece 17 when it is projected onto the rod 28a of the air cylinder 28. Notches are provided in the upper and lower surfaces of the mask films 5 and 6 at the portions from which the work holding means 27 protrudes, and a recess 3 is provided in the acrylic plate 3a of the top-burning frame as a relief portion for access during exposure. The workpiece holding means is not limited to this embodiment, and means such as vacuum suction of the sides of the workpiece using grooves or a large number of holes provided in conjunction with the acrylic plate 2a and mask film 5 may be used.

Next, a loader section that supplies a workpiece before exposure and an unloader section that takes out a workpiece after exposure will be explained with reference to FIG. The loader section 30 stores the workpiece before exposure, and the handler 31 moves downward to hold the workpiece by vacuum suction or the like, and moves upward again to carry it into the alignment section 13. During this transport, the moving table 9
moves to the exposure section 1 for exposure, and a workpiece receiving table 32, which is vertically movably disposed below a predetermined position of the alignment section 13, rises to the mask film position and receives the workpiece from the handler 31. At this point, the handler 31 returns and the alignment section 13
descends and picks up the workpiece 17 on the workpiece receiving table 32.
is attracted to the θ table and aligned in X, Y, and θ. On the other hand, the unloader section 33 includes a handler 34, and carries out the exposed workpiece by vacuum suction or the like after the overburning frame 3 has been raised and retracted.

The operation of the embodiment configured as above will be described. First, the vertical positioning of the mask film is manually set. At this time, the moving table 9 is positioned in the exposure section 1, and the mask film positioning pins 8 of the lower burning frame 2 are left protruding. The alignment holes of the mask films 5 and 6 are inserted into the pins 8 so as to be overlapped with each other, and they are attracted to the acrylic plates 3a and 2a of the upper and lower baking frames, respectively. After the mask film has been set as described above, the pins 8 are buried, the finishing frame 3 is raised and placed on standby, and the movable table 9 is positioned at a predetermined position in the alignment section 13.
Next, alignment tables 14, 15, 16,
18 descends and reads the alignment reference mark on the lower mask film 5 with the television camera 19.
The information is stored in the control unit 23. When the above preparation stage is completed, the moving table 9 returns to the exposure section 1, and the workpiece exposure process is executed in the following order.

(1) The workpiece receiving table 32 below the alignment section 13 is raised to the position where the mask film comes, and the workpiece 17 is received by the handler 31 of the loader section 30.

(2) After the alignment unit 13 descends, holds the workpiece 17 by suction and rises, the alignment mark on the workpiece is read by the television camera 19, and the X, Y, θ
Perform alignment.

(3) The work receiving table 32 is on standby, and the movable table 9 without a work moves to a predetermined position of the alignment section 13 and receives the aligned work 17 by lowering the alignment section 13.

(4) After the received work is fixed to the pre-baking frame 2 by the work holding claws 29a, it is moved to the moving table 9.
is moved to the exposure section 1 and positioned.

(5) The finishing frame 3 is lowered, and the mask films 5 and 6 are brought close to or in close contact with each other with the workpiece 17 in between by evacuation between the acrylic plates 2a and 3a, and exposure is performed.

(6) The finishing frame 3 rises and waits, and the exposed workpiece is carried out to the unloader section 33 by the handler 34.

In the above, alignment operations (1) and (2) and
The exposure operations (5) and (6) are performed at the same time from the second time onwards, as part of the assembly process. This eliminates wasted work time and improves production efficiency. Furthermore, since the aligned workpiece is directly held in the printing frame, the accuracy of positioning during exposure can be improved.

It should be noted that the present invention is not limited to the above-described embodiments, but can be applied to various embodiments in accordance with the gist of the present invention. For example, one printing frame and one image mask may be an upper printing frame and an image mask on the upper surface. In this case, the upper and lower mechanisms may be reversed. Further, the structure of the loader section and the unloader section is not limited to a handler, and a robot or the like may be used. The workpiece receiving table can be omitted by inverting the workpiece in the loader section and transferring it directly to the alignment section.

〔Effect of the invention〕

As described above, according to the present invention, the work aligned outside the exposure section is held directly in one of the printing frames, so that highly accurate alignment of the work and the image mask can be achieved. Further, the workpiece alignment operation and the exposure operation can be executed simultaneously in an assembly line, and there is no need to check the alignment in the exposure section or to process the case of poor alignment, so that production efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an apparatus according to an embodiment of the present invention seen from the front, FIG. 2 is a diagram showing the configuration of the alignment section and the configuration of the control section viewed from the bottom, and FIG. 3 is a diagram showing the configuration of the support member of the alignment section. The sectional view, FIG. 4, is a longitudinal sectional view of an embodiment of the workpiece holding means. 1...Exposed area, 2...Pre-printing frame (one printing frame), 3...
Top baking frame (the other baking frame), 5... Bottom mask film (one image mask), 6... Bottom mask film (the other image mask), 9... Moving table, 13...
Alignment section, 17... Work, 27... Work holding means.

Claims (1)

[Scope of Claims] 1. A means for carrying in a workpiece having a positioning mark, an alignment section that holds and aligns the workpiece carried in by the carrying means, and an aligned workpiece located directly below the alignment section. one baking frame on which the baking frame is placed, a moving table that reciprocates this baking frame from the alignment position to the exposure position, the other baking frame waiting at the moving end of this moving table, and the one baking frame and the other baking frame. The alignment section includes an exposure unit that performs exposure by sandwiching a workpiece therebetween, and a carry-out unit that carries out the workpiece that has been exposed in the exposure unit, and the alignment unit captures position information of the positioning mark of the workpiece and generates a signal. a control unit that calculates the amount of positional deviation of the positioning mark on the workpiece by comparing the received position information and pre-stored reference data, and outputs it as a displacement signal; and an alignment table that holds and aligns the workpiece based on the signal, and the one printing frame has a holding means that prevents the placed workpiece from shifting in position. Device.