JPS6015145B2 - automatic contact printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic reversing printing device suitable for producing a working plate from a master plate in the manufacture of integrated circuits, so-called ICs.

In this type of reversal printing process, in order to obtain a more precise transfer pattern than in the past, the master plate and working plate must be carefully removed from their respective storage positions, and both plates must be placed in the exposure position, overlapping each other accurately. Therefore, these operations were usually done manually.

In order to eliminate the waste of manpower and time due to manual work, as well as the high cost of products, attempts have been made to mechanize the removal of the master plate and working plate, their transportation to the exposure position, and their setting. However, with ordinary conveying machines, the plate surface may be scratched or dust may adhere, which poses a major obstacle to obtaining printed patterns that require sub-micron precision.
The object of the present invention is to automatically supply and collect the plate in a floating state to the set position, to perform contact printing from the master plate to the working plate as described above, and to perform the same operation after exposure. The objective is to provide a device for recovering the waste.

Still another object of the present invention is to provide means for automatically bringing the master plate and the working plate, which are specific to the exposure position, into close contact in a stereotaxic manner by means of a plate holder having an exposure field limiting frame and a vacuum chamber cooperating therewith. It is an object of the present invention to provide a fully automated contact printer that can be used in combination with the supply and collection device.

The automatic plate supply and collection device of the present invention includes a pair of plate supply cassettes for storing a large number of plates arranged for master plates and working plates, a similar pair of plate collection cassettes, and a pair of plate collection cassettes. It includes a main stage and an auxiliary non-contact air transport (air load) stage for transporting the plate from the supply cassette to the exposure position and then returning it to a pair of collection cassettes after exposure.

Here, a. The master plate supply cassettes and the working plate supply cassettes are each arranged at approximately equal intervals from the exposure position, and each has a magazine structure having side edge support bars for stacking a large number of plates in sequence at intervals. where the master plate is at a predetermined first level and the working plate is at a second, slightly lower level.
It is capable of vertically moving intermittently at the pitch of the plate stack to emit at a level toward the exposure position.

b The master plate collection cassette and the working plate collection cassette have substantially the same shape as the corresponding supply cassette and are arranged adjacent to each other, and the master plate and the working plate collection cassette are respectively returned from the direction of the exposure position at the first and second levels. In order to collect plates and working plates one by one, the crosspieces of each stage can be vertically moved to sequentially bring them to the plate collecting position.

c auxiliary loading means in said cassette are arranged so as not to impede said vertical movement of the cassette, ejecting plates from said supply cassette at said corresponding level and receiving plates from said collection cassette at said corresponding level; It generates a non-contact conveying air flow.

d The pair of air loading means for conveying and returning plates between each pair of plate supply and recovery cassettes to the exposure position each has a length corresponding to the distance between the pair of plate supply cassettes and the exposure position. a supply position for contactless pneumatic transport of the master plate and working plate discharged at the first and second levels from the pair of supply cassettes, respectively, to the exposure position; being able to selectively occupy collection positions for contactless pneumatic conveyance of the master plate and the working plate to the corresponding collection cassettes at the level, generating at each said position an oblique upward air flow inclined in the direction of the conveyance; It is something that can be done.

In addition, in the present invention, a device for closely contacting and fixing the master and working plates at the exposure position, which is used in combination with the above-mentioned Yokosei plate supply and recovery device, includes a field restriction frame, and a device for fixing the master plate that has been conveyed to the frame. The first step is to specially raise the
a lift means, a second lift means for lifting the conveyed working plate and bringing it into contact with the lower surface of the master plate, and a frame that starts and cooperates with the frame before the operation of the second lift means is completed; It consists of a plate for bringing the master plate and working plate into close contact. Here, the a field restriction frame is placed slightly above the first level, and has a vacuum channel for adsorbing the master plate transported to this position.

b The first lift means is for bringing the master plate below the frame into contact with the frame to help start vacuum suction of the master plate.

c. The second lifting means also prepares for vacuum suction by lifting the working plate brought below the frame and bringing it into contact with the vacuum suctioned master plate.

d) The plate holder contacts the frame and the working plate when both of the pair of air loading means are in the recovery position and before the operation of the second lifting means is completed, and the plate holder applies a vacuum to each contact surface of the frame and both plates. It has a vacuum chamber for contact. Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view schematically showing the plate supply and recovery steps of the present invention.

Here, circle 1 represents the exposure level, rectangular frames 2 and 3 arranged symmetrically on both sides represent supply cassettes for master plate and working plate, respectively, and rectangular frames adjacent to these supply cassettes. 4 and 5 represent recovery cassettes for master plate and working plate, respectively. Among the many master plates 6 and working plates 7 stored in the supply cassettes 2 and 3, the lowest
(described below with reference to FIGS. 3 and 3) are each brought to a predetermined level and then supplied to the exposure position 1 along arrows 8 and 9, respectively, by corresponding contactless air conveying means. Here, the master plate 6 and the working plate 7 are aligned and brought into close contact at the exposure position. The non-contact pneumatic conveyance means itself has a total length corresponding to the conveyance process and a width corresponding to the plate, so when aligning/adhering each plate and exposing, the arrow 1 is used.
As shown by 0a and 11a, it is translated to the position corresponding to the return stroke and is on standby so as not to interfere with these operations, and after exposure, it is moved back to the position corresponding to the original transport stroke along arrows EO10b and 11b. At the beginning and end, each plate released from vacuum contact is received and transferred again to the position corresponding to the return stroke, and then air flow for non-contact conveyance is generated in directions 12 and 13 opposite to the initial direction. Then, the master plate 6 and the working plate 7 are returned to empty berths that can accept the collection cassettes 4 and 5, respectively, and are available at a designated bell. FIG. 2 is an exploded perspective view showing the overall structure of the contact printer of the present invention having the plate supply and recovery processes as described above.

Here, the casings 14 and 15 on both sides of the exposure axis la accommodate supply cassettes and recovery cassettes for master plates and working plates, respectively, adjacent to each other and movable up and down. Master and working plate supply cassettes 2 and 3 respectively in casing 1
At the initial stage, the corresponding recovery cassettes 4 and 5 are at the lowest level recessed into the casing, and although not shown here, the master cassettes are attached to all the crosspieces of the general cassettes. It is assumed that the plate and working plate are thin.
These plates pass over the upper edges of casings 14 and 15 into and out of the cassette, so that casing 14
and 15 respectively correspond to the specific transport levels of the master plate and the working plate, and thus the pair of air loading devices 16 and 17 extending in opposite directions from the casings 14 and 15 correspond to these upper green levels. Support members 20 and 21 at both ends of each slide shaft are slidably held on the slide shafts 18 and 19 and 19, respectively, at the level where
and 22 and 23 are stoppers for the air load devices 16 and 17, respectively, and the air load devices 1
The total length of 6 and 17 is the same as that of stoppers 20 and 2.
It extends to the extent that it closes the opening 25 of the field limiting frame 24 that sets the exposure position of the plate at the supply position in contact with the field limiting frame 24. The frame 241 is provided with a channel for vacuum suction of the master plate, which will be described later with reference to FIG. 6, and a movable air nozzle 26 is arranged below the periphery for releasing the close contact between the two plates. Further below the working plate air road 17, there are arranged a plate chuck rod 27 whose axis ○ is aligned with the exposure axis la, and a plate holder 28 which extends through this rod 27 and is also movable up and down. There is. In this case, a four-point plate support pin 29 that is driven by air, for example, is disposed on the top surface of the tip of the master plate air load device 16 in conjunction with the plate chuck rod 27. A notch 30 through which the plate chuck rod 27 described above passes is formed. An exposure optical system is arranged above the frame 24 from the light source to the frame.

Here, 31 is a light source consisting of an ultra-high pressure mercury lamp, 32 is a protector, 33 is a cosodenser lens, 34 is a shutter,
35 is a filter, 36 is a field lens, and 37
is a cold mirror for directing light toward the frame 24. The details and operation order of each part in the embodiment having the above-mentioned configuration are as follows.

FIG. 3 shows cross sections along the conveyance axis of the supply cassette 2 for the master plate 6 and the air loading device 16 in the supply position, respectively. As mentioned above, the cassette 2 is initially set at the top, and the air load device 16 is placed at the top. The lower master plate 6 is located slightly above the upper green of the casing 14.

The inside of the cassette 2 is at the same level as the upper surface of the outer air load device 16 and the upper surface of the casing 14}, that is, the lowest master plate 6a stored in the cassette 2.
An auxiliary whose top surface is set slightly below. - code device 3
8 is fixed so as not to impede the descent of the cassette 2. In order to transport the upper surface of the air load device 16 to a position where the master plate 6 does not come into contact with it and aligns with the exposure axis la, there is a
A row of orifices 39 for ejecting air in an inclined upward direction and about 30 orifices in the opposite direction (toward the cassette).
A second row of orifices 40 is formed for blowing out air obliquely upward. Also, the auxiliary load device 38
A similar row of orifices 41 and 42 is formed in the stone, although the orifice 42 facing upward in the figure is not necessarily required. As can be seen from the horizontal cross section shown in FIG. 4, the orifices 39 and 40 of the air loading device 16 are
They are arranged in collinear rows, allowing the plates to float horizontally. This orifice arrangement is similar in the auxiliary loading device. Now, set the cassette 2 and air load device 16 as shown in FIG. The airflow is energized to blow out from the IJ office rows 39 and 41 which are inclined to the side.

Therefore, the lowest master plate 6 is. It is ejected from the cassette 2 without touching the top surface of the card devices 38, 16, and is conveyed to the exposure axis la, and when it hits the stopper 43 in FIG. 3 and the arrival at this position is detected by the photo sensor 44, These air flows are stopped. A detailed external diagram of the air loading device 16 or 17 is shown in FIG. Both side edges 45 and 46 are provided, and the aforementioned stopper 43 is placed at the center of the tip, and the aforementioned photo sensor 44 is placed at the corner of the tip.

The master plate 6 conveyed to the exposure axis is then lifted by a four-point pin 29 energized by a suitable air system and brought into contact with the lower surface of the frame 24 .

At the same time, the vacuum suction means of the frame 24 is energized to suction and hold the master plate 6 in contact with it. At this point, the four-point pin 29 is lowered to its original level, and the master plate air-loading device 16 is set to the recovery position, that is, the position supporting the stopper 21 in FIG.

The working plate 7 is supplied after the master plate 6 has been supplied to the exposure position.

The supply cassette 3 for this purpose, the auxiliary loading device therein, and the air loading device 17 can be considered to be substantially symmetrical to the one for the master plate 6 described above with reference to FIG. Detailed illustrations are omitted. It should also be noted that the auxiliary loading devices in the recovery cassettes 4 and 5 are also oriented so that the orifice rows can receive at least the plates in the cassettes, and the supply cassettes are equipped with a photo sensor for detection of recovery. It is similar to those in 2 and 3. First, in FIG. 2, the working air loading device 17 is set to the supply position, that is, the position supporting the stopper 22, and then
The auxiliary loading device (not shown) and the air loading device 17 inside are energized to eject the lowermost working plate, and it is conveyed by contactless air until it corresponds to the exposure axis, and this conveying air flow is applied in the same manner as above. Then, the plate chuck rod 27 is raised through the notch 30 at the tip of the air loading device 17, and the working plate is specially raised by the chuck plate at the tip of the rod 27 (at this time, suction operation of the chuck is not particularly necessary). , is brought into contact with the lower surface of the master plate 6, which has already been attracted to the frame 24. Preferably, rod 27 senses this contact pressure and stops. Here, the working air load device 17 is at the recovery position,
That is, it is reset to the position where it abuts against the stopper 23 in FIG. Next, as shown in FIG. 6, the plate holder 28 is raised from the lower rest position shown by the imaginary line to the operating position shown by the solid line, and the entire upper end of the outer annular or rectangular frame-shaped rubber blade 47 is lifted up. M2
The entire upper end of an inner frame-shaped receiving rubber 49 that is slightly larger than the opening □ 25 of the frame is brought into pressure contact with the lower surface of the working plate 7.

At this point, the role of the chuck rod 27 is completed, and the chuck rod 27 is returned from the upper end support position shown in the virtual diagram to the lower end resting position shown in the solid line diagram. Again, as is clear from FIG. 6, on the back side of the frame 24, which has an outer diameter larger than that of the plates 6 and 7, the circumferential green 48 corresponding to the outer edge of the master plate 6 is slightly smaller than the lower end surface 50 that connects to the closing opening 25 on the inside thereof. ,
Preferably, it is stepped by a depth of about 1 to 2 degrees, and an annular vacuum channel 51 is carved between the circumferential green 48 and the lower end surface 50.

Therefore, the vacuum channel 51 is used to attract the master plate 6 by the frame 24 described above. That is, if the step of the circumferential green 48 is about 1 to 2 degrees, when the vacuum channel 51 is depressurized, the outer edge of the master plate 6 will substantially sag by the step difference and come into contact with or come close to the circumferential edge 48 , causing the vacuum channel 51 It can be considered that the frame 24 is completely isolated from the outside air.
It is possible to adsorb the master plate 6 even by itself. Further, as shown by the solid line in FIG. 6, when the plate holder 28 presses the working plate 7 against the master plate 6 and the upper end of the outer rubber blade 47 comes into pressure contact with the peripheral edge 48 of the frame 24,
The vacuum suction of the master plate by the frame 24 is released, the invisible deflection of the master plate 6 is restored, and the vacuum chamber 52 of the plate holder 28,
In other words, a vacuum source (not shown) is connected between the outer and inner rubber.
Connect to. As a result, air and attached dust are removed from the contact surface between the master plate 6 and the working plate 7, and the two plates are brought into close contact with each other. Since the vacuum simultaneously extends between the back surface of the frame 24 and the top surface of the master plate 6, they are brought into close contact with each other.
In the embodiment of the present invention, the lower end surface 50 of the frame and the stepped peripheral edge 48 are subjected to ultra-precision processing. In this way, in the frame structure shown in FIG.
, 7, the gap between the outer rubber blade 47, and the vacuum chamber 52 of the frame holder 28 are all subjected to a vacuum of substantially equal strength throughout the depressurization process. This solves the problem of plate deflection that occurs in frames having a flat, precision (not ultra-precision) finished bottom surface commonly employed in conventional mechanisms of this type. That is, if the underside of the frame is flush-finished on both sides of the narrow plate suction vacuum channels, there is a substantial air resistance to leakage air through the frame-master plate contact gap and an air buffer provided by the channels. When the pressure is reduced from the outer edge by the vacuum chamber 52, the part outside the adsorption channel is first reduced in pressure, and this part of the master plate first comes into close contact with the frame, and then the part inside the channel is reduced. The part is shaped almost in communication with the outside air at a much higher pressure, so that the plate deforms in a concave manner, with this inner part away from the frame. The depth of this deflection or dip is very small, for example if the deflection in the center is 1
Even if it is about 2 Buddhas, the cumulative transcription accuracy reaches 1 mu, and I
This results in pattern defects during C manufacturing. In the frame of the present invention, the inside of the channel 51 is reduced in pressure via the step circumference 48 of 21, and this is transmitted to the lower end surface 501. At that time, there is virtually no pressure gradient on the plate surface in contact with this vacuum region, so the plate
The outer side of the plate 6 does not bend upward first, and since the lower end surface 50' of the frame is ultra-precision machined, there is no substantial air resistance during rough contact (mechanical contact) with the plate 6, so this contact gap is By bringing the two into close contact with each other at the same time as the pressure is reduced, the problem of deflection can be completely overcome. When such vacuum contact is completely achieved, exposure is then performed, and therefore the exposure shutter can be configured to open automatically after a set time. However, as illustrated in Fig. 7, the plate deflection and adhesion state are monitored before and during exposure, and if incomplete adhesion is observed just before exposure, the operator will be able to determine whether a desired adhesion has been achieved. You can arbitrarily delay the shutter opening time until the In FIG. 7, an ultra-high-pressure mercury lamp 31 emits a wavelength for curing the photoresist film on the working plate 7, but the photoresist film not only receives this light but also constantly leaks light (the device of the present invention is used in a dark room). Even light leakage from an indoor safety light that emits wavelengths that do not affect the photoresist film is reflected toward the cold mirror 37, and this reflected light produces interference fringes on the cold mirror 37 that indicate the degree of close contact between the two plates. Cheating. The cold mirror reflects visible light and transmits heat rays, allowing the operator to monitor such interference fringes from behind the cold mirror in a dark room. Clear interference fringes and Newton's rings based on the presence of dust between the plates can be easily identified. Furthermore, even if both plates are in good contact with each other before exposure, sagging may occur (this is due to gas generation from the photoresist film) when the plate 34 is opened and exposed for several seconds. By checking the working plate when such a situation is observed, it is possible to prevent a working plate having a pattern error from being used for actual IC pattern printing. In this way, when the exposure of the working plate 7 (for about several seconds) is completed, the shutter 34 is closed again, the plate adsorption mechanism of the frame 24 itself is activated again, and then the plate chuck rod 27 is raised and brought into contact with the working plate 7. .

At this point, the vacuum contact caused by the plate holder 28' is released and the holder 28 is lowered. At the same time as this suction is released, an inert gas such as nitrogen is supplied into the vacuum chamber of the holder 28 by an appropriate means to help release the close contact between the plates 6 and 7. Next, at the same time as releasing the nitrogen gas atmosphere, the working plate air load 16 is returned to the original supply position.

At this time, the tip of the plate chuck rod 27 is already above the air load 17, but the notch 30 at the tip of the air load 17 partially shown in FIG. The process is carried out without any problem. Here, the plate chuck rod 27 is connected to a vacuum source, the working plate 7 is attracted to its end face, and then lowered. At the same time, the moving air nozzle 26 shown in FIG. It advances toward the contact end green at rates 6 and 7 and blows out an inert gas, for example nitrogen gas, as in the case of releasing the vacuum, and this is stopped when the plates 6 and 7 are separated. When the working plate 7 is placed on the air loading device 17 by lowering the chuck rod 27, this is detected by appropriate means and the plate adsorption by the end surface of the rod 27 is released. When the chuck rod 27 is completely lowered, the air loading device 17 is reset to the recovery position, and at the same time, a contactless conveyance air flow for recovery of the air loading device 17 and the auxiliary loading device in the working plate recovery cassette 5 is generated, The exposed working plate 7 is collected into the same cassette 5.

Next, the master plate air loading device 16 is set to the supply position. Here, the four-point pin 29 is raised to contact the master plate 6, the vacuum suction of the master plate 6 by the frame 24 is released, and the four-point pin 29 is lowered to transfer this plate to the air load device 16.
and move it to the collection position again. Then, the air load device 16 brought to the recovery position and the master plate 6 in which the auxiliary load device in the recovery cassette 4 is energized are transferred to the recovery cassette 4 and recovered. When receiving the first square and working plates 6 and 7, the recovery cassettes 4 and 5 are at the lowest position, contrary to the supply cassette, and the plates are placed at the top. is collected, and each time the number of sheets increases, it is raised one step at a time, and the lower bars are sequentially made to correspond to the predetermined acceptance level (first and second level),
The state at the time of initial recovery is as shown in FIG. In this case as well, the air loading device 16, collection cassette 4, and auxiliary loading device 53 for the master plate are shown, but the air loading device 16 for the master plate can be considered to be symmetrical with these. In the auxiliary loading device 53, the end 54 shown in green on the opposite side from the air loading device 16 detects the plate and directs the recovery air flow (orifices 40, 42 with diagonal lines).
This is a photo sensor to stop the After the exposed plates 6 and 7 are collected in the cassettes 4 and 6, the vacuum channel of the frame 24 is connected to a vacuum source and the next master plate is transferred to the cassette 4 and 6. Make preparations to ensure smooth adsorption.

Next, regarding the plate, first set the supply cassettes 2 and 3 to 1.
By lowering the step, the next lowest plates 6 and 7 are set to the first and second levels, respectively.
Further, by raising the recovery cassettes 4 and 5 by one level, these plates 6 and 7 are received at the first and second levels, respectively, and the same procedure as described above is repeated.

As a result, an exposure process is applied to all the plates stored in the supply cassettes 2 and 3 through automatic, non-contact transport that does not cause any damage.

When all the plates have been stored in the collection cassettes 4 and 5, the full set can be removed from the casings 14 and 15, or if desired, the air loading device 16
, 17, a similar air loading device connected to the cassette from the opposite side allows new plates to be loaded into the supply cassette and exposed plates to be removed from the collection cassette.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the relationship between plate supply and recovery and exposure position of the present invention, FIG. 2 is an exploded perspective view showing the overall configuration of an embodiment of the present invention, and FIG. 3 is a master plate supply cassette and A cross-sectional view showing the main and auxiliary air loading devices, FIG. 4 is a horizontal sectional view of the main air loading device, FIG. 5 is a detailed perspective view of the main air loading device, and FIG. 6 shows the master plate and working plate in the exposure position. Fig. 7 is a schematic diagram showing the mechanism for monitoring the adhesion state from the light source to the exposure optical system to the plate, and Fig. 8 is a cross-sectional view showing the mechanism for vacuum adhesion and fixation between the master plate collection cassette and the main plate. FIG. 4 is a cross-sectional view similar to FIG. 3 showing the auxiliary air loading device. 2, 4...Cassette for master plate, 3, 5...Cassette for working plate, 6...Master plate, 7...Cassette for working plate. Rate, 16, 17... Air load device, 2
4...Exposure field restriction frame, 38,
53... Auxiliary loading device, 27... Plate chuck rod (second lifting means), 28...
... Plate holder, 29 ... Plate support 4-point pin (first lift means), 31 ... Light source, 34.
...shutter, 37...cold mirror, 39
, 41...conveying air orifice for plate supply, 40,
42... Conveying air orifice for plate recovery. 1st
Figure 3 Figure 4 Figure 5 Figure 7 Figure 2 Figure 6 Figure 8

Claims (1)

[Scope of Claims] 1 a. A large number of master plates and working plates are arranged at approximately equal intervals from the exposure position, and are stacked one by one with gaps between each by side edge support bars,
A pair of magazine structures that can be stored, and for releasing the stored master plate and working plate one by one toward the exposure position at a predetermined first level and a second level slightly lower than this, respectively. a pair of plate supply cassettes, one for a master plate and the other for a working plate, which can be vertically moved in sequence; b. a pair of plate supply cassettes having substantially the same shape as corresponding supply cassettes disposed adjacent to the pair of plate supply cassettes, respectively; Each of the first and second cassettes
and a second level that is capable of moving vertically to sequentially bring the crosspieces of each stage to the plate collection position in order to collect the master plate and working plate returned one by one substantially from the direction of the exposure position. a pair of plate recovery cassettes, one for the master plate and the other for the working plate; a respective pair of auxiliary loading means for generating a contactless conveying air stream for ejecting from the supply cassette at said predetermined level and receiving in a collection cassette; a supply position having corresponding lengths for contactless pneumatic transport of master plates and working plates discharged from respective supply cassettes at said first and second levels to said exposure position; One of the master plates occupies a recovery position for contactless pneumatic conveyance of the master plate and the working plate, respectively, to the corresponding recovery cassette at the second level, and in each said position an air stream can be generated inclined in the corresponding conveyance direction. a pair of air loading means, one for the plate and the other for the working plate;
An automatic contact printer for transferring a pattern on a master plate to a working plate, characterized in that it is equipped with a plate supply and recovery device from a cassette consisting of a cassette to an exposure position and a recovery device. 2. In the contact printer according to claim 1, a. an exposure device that is disposed slightly above the first level in the exposure position and has a vacuum channel for adsorbing the master plate conveyed to this position; a first lifting means for lifting the master plate brought under the frame and bringing it into contact with the frame to help start vacuum suction of the master plate; c. a first lift means brought under the frame; a second lift means for lifting the brought working plate and bringing it into contact with the lower surface of the adsorbed master plate; A plate holder having a vacuum chamber for contacting the frame and the working plate before finishing and vacuum-adhering the frame and each contact surface of both plates. Automatic contact printer for transferring to.