JPH11119439A - LCD mask type exposure marking system - Google Patents

Abstract

An object of the present invention is to shorten the processing time of exposure marking and establish a highly efficient and clear exposure marking technique. A third harmonic of a YAG laser has a wavelength of 35.
Ultraviolet laser light 2 from a laser oscillator 1 that oscillates a 5 nm laser light is efficiently and collectively exposed and marked at a desired position on a liquid crystal display glass substrate 12 which is a member to be exposed in a processing chamber 13. For this purpose, a half-wave plate 4, a laser beam magnifying lens system 5, a polarizing beam splitter 9, a reflecting mirror 10, a processing chamber 13, and a reduction imaging lens 11 are provided, and an ultraviolet laser beam transmission type exposure pattern is provided. The above problem is solved by using a liquid crystal panel type mask 6 for production.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal mask type exposure marking apparatus, and more particularly to a liquid crystal mask type exposure marking apparatus suitable for, for example, a liquid crystal display for performing ultraviolet exposure marking on a photosensitive member coated with a photoresist.

[0002]

2. Description of the Related Art Generally, in a flat display using a liquid crystal panel, a control number is marked on a glass substrate and a color filter constituting the liquid crystal panel in a manufacturing process for the purpose of production control.

[0003] The first prior art of marking at that time is roughly classified into a direct drawing type using a laser beam and an exposure type using an ultraviolet ray. It was divided into types. Metal mask exposure using ultraviolet light selects and uses only the ultraviolet light of a lamp (a mercury lamp or the like) as a light source. In one-stroke exposure using ultraviolet light, a thin beam of ultraviolet laser light is used as a scan mirror. And the like to perform exposure marking by scanning.

Further, as a second prior art, as shown in FIG. 14, a lamp is used as a light source 101 and an exposure pattern is formed by pixels of a liquid crystal panel 103 to form an exposure pattern.
3 is formed by forming an exposure pattern image on a liquid crystal panel surface on a printed circuit board 105 by using an image forming lens 104 with the light passing through the light emitting device 3 to perform exposure marking.
No. 718 proposes.

[0005]

By the way, the prior art shown above does not consider the following points. That is, in the first prior art, it is necessary to replace the mask each time the control number changes, and in the single-stroke writing method, a laser beam is scanned by a scan mirror or the like, so that the marking pattern is written in a short time. Was not suitable for. Therefore, a large substrate (1m × 1
In the case where several substrates are taken out from m), marking must be made at 10 or more locations on a large substrate, and no consideration has been given to having a high-speed processing function.

The second prior art uses a liquid crystal panel as a mask and thus has a high-speed processing function in that respect. However, since the light source is a lamp, the energy that contributes to the exposure cannot be large. As a result, the exposure processing time could not be shortened, and no consideration was given to having a high-speed processing function as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to provide a liquid crystal mask-type exposure marking apparatus capable of not only shortening the processing time of exposure marking, but also providing clear marking. To offer.

[0008]

According to the present invention, in order to achieve the above object, a light source for exposure is an ultraviolet laser oscillator, and a polarizing beam splitter is arranged at a subsequent stage of a liquid crystal panel type mask. The ultraviolet laser light that has passed through the mask pattern of the mask and the other ultraviolet laser light are separated by the polarizing beam splitter, and the ultraviolet laser light that has passed through the mask pattern separated by the polarizing beam splitter is subjected to a reduction imaging optical system. It is characterized by irradiating an object to be exposed through a mark to perform marking.

Further, it is more preferable that the liquid crystal panel type mask is composed of dot-shaped liquid crystal pixels, and the liquid crystal molecule initial setting twist angle of the liquid crystal panel type mask is 180 to 270 degrees.

That is, in the present invention, an ultraviolet laser is used as a light source for exposure, and a liquid crystal panel is used as an exposure mask, so that the exposure pattern of characters and figures can be freely changed in a short time by an electric signal from a control computer. Further, the present invention is characterized in that the processing time is short and accurate exposure marking is performed by configuring the liquid crystal panel with a material having high transmittance to an ultraviolet laser.

As described above, in a single-panel type liquid crystal display substrate in which a large substrate is divided into several substrates after the end of the pre-process at the time of manufacturing, the pattern to be marked is divided in order to perform exposure marking in the pre-process stage. It will be different for each substrate. However, by using the liquid crystal panel as a pattern mask, it is possible to switch mask patterns in a short time. In addition, since ultraviolet light is a laser beam, the directivity of the laser beam is good, and the light condensing property of the lens and the like is good, so that the energy density for exposure can be increased and the exposure irradiation time can be shortened. Becomes possible. As compared with the case of using ultraviolet rays from a lamp as described in the conventional example, it is possible to provide a liquid crystal mask type exposure marking apparatus which can shorten the exposure processing time and has high production efficiency.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a liquid crystal mask type exposure marking apparatus according to the present invention.

As shown in FIG. 1, the liquid crystal mask type exposure marking apparatus of this embodiment emits an ultraviolet laser beam 2 having a wavelength of 355 nm (third harmonic of a YAG laser) oscillated from a laser oscillator 1 in a processing chamber 13. A desired position on the glass substrate 12 for a liquid crystal display, which is a member to be exposed, is efficiently and collectively irradiated to perform exposure marking. For this purpose, a half-wave plate 4, a laser beam magnifying lens system 5, It includes a liquid crystal panel type mask 6 for forming a pattern, a polarizing beam splitter 9, a reflecting mirror 10, a processing chamber 13, and a reduction imaging lens 11 (the details of which will be described later). Before describing the configuration of the present embodiment, a liquid crystal display panel handled in the present embodiment will be described. Liquid crystal display panels include a passive matrix type and an active matrix type. At present, a TFT (Thin Film Transistor) type liquid crystal display which is an active matrix type is mainly used.

FIG. 2 shows a general sectional structure of the TFT type liquid crystal display. From the lower side of the figure, a laminated structure of a polarizing plate 20a, a glass substrate 21a, a TFT array 22, an alignment film 23a, a liquid crystal layer 24, an alignment film 23b, a counter transparent electrode 25, a color filter 26, a glass substrate 21b, and a polarizing plate 20b. Has become. One pixel is constituted by a portion of an arc 28 including the TFT portion 27, and these are arranged in a matrix. The object to be dealt with in the present invention relates to an array process for forming a TFT array 22 formed on a glass substrate 21a therein.
6 relates to the manufacturing process. In the TFT array process, the photo engraving process technology (Photo E
ngraving Process (hereinafter abbreviated as PEP). The outline of the PEP process is as follows.

That is, a photoresist sensitive to ultraviolet rays is applied on a glass substrate on which a metal (Mo, Co, ITO film, etc.) is deposited, and a pattern mask is placed thereon and irradiated with ultraviolet rays. The portion of the photoresist where the ultraviolet light is blocked by the mask becomes hard, and conversely, the portion of the photoresist where the ultraviolet light is irradiated without being blocked by the mask becomes soft. Such a photoresist is called a positive resist,
The opposite type of photoresist is called a negative resist. Next, the cured portion of the resist is removed by processing with a developer. Unnecessary metal film portions under the removed resist are removed by etching, and the last remaining resist film is removed, thereby completing a series of PEP steps. By repeating such a PEP process several times, a semiconductor element and a circuit pattern are formed. An ultraviolet lamp such as a mercury lamp is generally used as an ultraviolet light source used in the PEP process in the array process, and a metal mask is used as a mask.

The present invention is characterized in that a liquid crystal mask is used as a substitute for the metal mask used in the array process, and an ultraviolet laser light is used as an ultraviolet light source. Particularly, it is most suitable for imprinting a production control number of a glass substrate which is a part of the array process.

The structure of the present invention used in such a liquid crystal display manufacturing process will be described. A laser oscillator 1 oscillates an ultraviolet laser beam 2, and in this example, for example, 1064 nm which is a fundamental wave of a YAG laser. Infrared light of a wavelength of a nonlinear optical element (eg, KTP, BBO, LB
O) is pulsed to oscillate the third harmonic ultraviolet laser light 2 (wavelength: 355 nm). The polarization of the ultraviolet laser light 2 is a linearly polarized laser light having only one polarization direction, and the polarization angle of the ultraviolet laser light 2 having passed through the optical shutter 3 is changed by a half-wave plate 4 to a liquid crystal panel type mask. The polarization direction is rotated so that the optimum incident polarization angle of 6 is obtained. Further, the ultraviolet laser beam 2 is expanded by the laser beam expanding lens system 5 so that the ultraviolet laser beam 2 becomes large enough to be incident on the entire laser light transmitting surface of the liquid crystal panel type mask 6. In this example, the size of the laser light transmitting surface of the liquid crystal panel type mask 6 is 35 mm × 65 mm, and the beam diameter of the ultraviolet laser 2 before entering the laser beam magnifying lens system 5 is 1 to 2 mm. I have. That is, in the laser beam expanding lens system 5, the beam diameter is 1 to
The ultraviolet laser beam 2 having a diameter of 2 mm is configured to be expanded into a 35 mm × 65 mm ultraviolet laser beam 2, and the expanded ultraviolet laser beam 2 is incident on a liquid crystal panel type mask 6.
The liquid crystal panel type mask 6 has a control device 7 and a driving power source 8 in advance.
Thus, an exposure mask pattern is created. When the ultraviolet laser beam 2 passes through the liquid crystal panel type mask 6, the laser beam passing through the portion where the mask pattern is formed and the laser beam passing through other portions are polarized by the liquid crystal panel type mask. Will be different. Therefore, a polarizing beam splitter 9 is provided to separate the two laser beams having different polarization directions.
The ultraviolet laser light 2 that has passed through the mask pattern portion passes through the polarization beam splitter 9 as the ultraviolet laser light 2a, and the ultraviolet laser light 2 that has passed the other portions is reflected as the ultraviolet laser light 2b by the polarizing beam splitter 9. Will be. As a result, only the ultraviolet laser beam 2b on which the mask pattern is formed is reflected by the reflecting mirror 10, and the reduction imaging lens 11 installed in the processing chamber 13
In this way, the mask pattern image formed on the liquid crystal panel type mask 6 is reduced and transferred to the glass substrate 12 for liquid crystal display to be exposed and marked.

In this embodiment, an ultraviolet laser, which is the third harmonic of the YAG laser, is used as the light source for exposure, so that the characteristic that laser light is condensed well can be utilized. Marking is possible. The same effect can be obtained by using an excimer laser (wavelength: 308 nm, 254 nm, 198 nm, etc.) as the ultraviolet laser, and the excimer laser can obtain a higher energy intensity than the third harmonic of the YAG laser. In addition, it is possible to perform a large-area batch exposure mark, and it is possible to shorten the exposure marking time. Next, the details of the liquid crystal panel type mask 6 will be described. FIG. 3 is a cross-sectional view of the liquid crystal panel type mask 6 used in this embodiment. In the figure, reference numerals 30a and 30b denote glass substrates, on each of which pixel electrode (transparent electrode) films 31, 32 having a width of 240 μm are formed at equal intervals, and are opposed to each other so as to form a grid. I have. The pixel electrode films 31 and 32 are formed of an ITO (Indium Tin Oxide) film. On the upper layer of the ITO film, there are alignment films 33a and 33b in which grooves formed for determining the alignment direction of liquid crystal molecules are formed by applying a solution obtained by dissolving a polyimide resin in a solvent. Then, there is a spacer 35 made of beads that determines the gap length of the liquid crystal layer. The periphery of the glass substrate is sealed with a sealant, and the liquid crystal material 34 is injected and completely sealed to form a liquid crystal panel. ing. This is generally called a simple matrix type liquid crystal panel.

This simple matrix type liquid crystal panel is mainly classified into two types, a TN (Twisted Nematic) type and an ST type.
There is an N (Super-Twisted Nematic) type. The TN type is arranged such that the major axis direction of the liquid crystal molecules is parallel to the electrode surface by the alignment film, and the major axis direction of the molecules is 90 ° while going from one electrode substrate to the other electrode substrate.
It is arranged so that it is gradually twisted below. On the other hand, in the STN mode, the long axis direction of the liquid crystal molecules is arranged so as to be parallel to the electrode surface, and the long axis direction of the molecules is 1 during the movement from one electrode substrate to the other electrode substrate.
They are arranged so as to gradually twist by 80 to 360 °. The TN type utilizes the optical rotation of liquid crystal molecules with respect to an electric field applied between the liquid crystal layer gaps, whereas the STN type
The mold utilizes the birefringence of liquid crystal molecules for a similar electric field. In this embodiment, a STN type liquid crystal panel of a time division driving system capable of expressing a character pattern with a simple configuration is used. The initial rotation angle in the liquid crystal molecule long axis direction between the liquid crystal layer gaps is 240 °.

FIGS. 4 and 5 show the principle of operation when a linearly polarized ultraviolet laser beam having a wavelength of 355 nm and a third harmonic of the YAG laser of this embodiment is incident. In both figures, the difference in the polarization direction of the laser light when no voltage is applied to the pixel electrode (FIG. 4) and when the voltage is applied (FIG. 5) when the laser light enters the liquid crystal panel type mask 6 from the back side of the drawing. Is shown.

In the case where no voltage is applied to the pixel electrode in FIG. 4, the liquid crystal molecules are arranged so that the longitudinal direction of the liquid crystal molecules is gradually twisted by 240 ° between the electrode substrates as described above, and the direction of the arrow 40 is the laser light. The direction of the arrow 41 is the direction of the long axis of the liquid crystal molecules on the incident side, and the direction of the arrow 41 is the direction of the long axis of the liquid crystal molecules on the laser beam emission side rotated by φ = 240 °. In this state, the linearly polarized ultraviolet laser light 2
When the light is incident in the polarization direction of 45 °, the emitted laser light is shifted by P with respect to the polarization axis of the incident laser light due to the birefringence of the liquid crystal molecules.
It becomes the elliptically polarized ultraviolet laser beam 2b having the main component of polarization in the direction of the arrow 43a of θ = 120 °. On the other hand, when a voltage sufficient to drive the liquid crystal molecules is applied to the pixel electrode in FIG. 5, the light is emitted as elliptically polarized ultraviolet laser light 2a having a main component of polarization in the direction of arrow 43b of Pθ = 30 °.

FIG. 6 shows the characteristics of the transmittance T with respect to the applied voltage Vop of the ultraviolet laser beam 2a in this embodiment. The characteristic curve of N is a transmittance characteristic of a selected pixel (a pixel to which a voltage is applied), and Ns is a transmittance characteristic of a non-selected pixel (a pixel to which a voltage is not applied) adjacent to the selected pixel.
In other words, when a voltage is applied to the selected pixel and the voltage is increased, the voltage is applied to the adjacent non-selected pixel in a leaking manner, so that the laser light is transmitted through the non-selected pixel. Is an Ns curve. Here, the voltage at which the relative transmittance T of the selected pixel characteristic N changes by 90% is generally defined as the operation saturation drive voltage Vs-sat of the selected pixel, and the relative transmittance T of the non-selected pixel characteristic Ns is 10%. The changing voltage is defined as the operation threshold voltage Vns-th of the non-selected pixel. Also, the ratio of the transmittance T between the N characteristic and the Ns characteristic between Vs-sat and Vns-th is defined as contrast k, and represents the degree of lightness and darkness. That is, Vns-th
Is sufficiently larger than Vs-sat, high contrast can be obtained in a wide operating voltage region.

In the exposure marking step according to the present invention,
Since a large number of the above-described PEP processes are included, clear exposure marking is essential, and in order to realize this,
Experiments have shown that the value of the contrast k is required to be k = 15 or more. In the present embodiment, a maximum contrast k = 25 exceeding this is obtained by experiments.

As one of the factors that determine the contrast,
There is a twist angle which is a set angle in the long axis direction of the liquid crystal molecules in the liquid crystal layer of the liquid crystal panel type mask, and the characteristics are shown in FIG. In the present embodiment, the twist angle Φ is set to 240 °. However, from FIG. 7, it is understood that the contrast k = 15 or more is satisfied if the twist angle Φ is 180 ° or more. Considering that the change in contrast becomes small when the twist angle Φ = 270 ° or more, the twist angle Φ
Can be said to be in the practical range of 180 ° to 270 °.

As a factor other than the twist angle that determines the specifications of the liquid crystal panel, the product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn of the liquid crystal material is generally important. Widely known in various liquid crystal panels. Therefore, Δn · d in the present embodiment will be described below.

FIG. 8 shows the laser light wavelength 355 in this embodiment.
nm, twist angle Φ of liquid crystal molecules of liquid crystal panel type mask =
4 shows the result of a theoretical condition calculation in which laser light in the direction 2a in FIG. 4 (polarization direction having a maximum transmittance when a voltage is applied) can be completely blocked when no voltage is applied to the liquid crystal panel at 240 °. Was. As a result, Δn · d at which the relative transmittance T becomes 0% under the conditions of the present embodiment is 0.5.
It can be seen that the points are 2 μm and 0.95 μm. But,
It is known that the smaller the value of Δn · d, the higher the transmittance of the laser beam when a voltage is applied. The higher the value, the better the value of Δn · d in this embodiment is 0.52 μm.
Is good.

FIG. 9 shows the result of condition calculation of the maximum light shielding Δn · d with respect to the twist angle of the liquid crystal molecules. Here, the practical range of the twist angle Φ is 180 ° as shown in FIG.
２270 °, Δn · d in the range surrounded by the dashed line becomes Δn · d in the practical range, and 0.45
It suffices to be in the range of .about.0.75 .mu.m. That is, if a liquid crystal panel is manufactured with Δn · d within this range,
Under the laser beam having a wavelength of 355 nm, the theoretical light-shielding condition is almost satisfied. Therefore, the fact that light can be completely shielded when no voltage is applied means that the use of a liquid crystal panel within the above-mentioned range further enhances the above-mentioned contrast and enables clear marking.

The liquid crystal mask type exposure marking apparatus in this embodiment performs a marking operation 1 to 5 times per second. For that purpose, the liquid crystal panel used as a mask
A response speed of mask pattern display switching that can correspond to this marking speed is required. This response time is closely related to the gap length of the liquid crystal layer, and the characteristics at a wavelength of 355 nm in this embodiment are shown in FIG. In this figure, the response time t1 is the time from when the driving voltage is turned on until the movement of the liquid crystal molecules is completed. The display maintaining time, which is the minimum required as a mask, and when the driving voltage is turned off, the liquid crystal molecules are initialized. The sum of the times required to return to the state must be faster than the exposure marking repetition rate. At present, it is known that 1/4 of the integration time should be t1 or less, and 1 Hz operation is 1/4 of 1 second.
= 250 ms, 1/4 of 200 ms for 5 Hz operation = 5
It is sufficient that t1 is 0 ms or less. From this, it can be seen from FIG. 10 that a liquid crystal panel type mask can be manufactured with the gap length of the liquid crystal layer being in the range of 4.5 to 7.5 μm. Further, the applicable range of Δn · d is 0.45 to 0.45.
0.75 μm, and the range of the gap length d of the liquid crystal layer is 4.75 μm.
Since the refractive index anisotropy Δn of the liquid crystal material is specified in the range of 5 to 7.5 μm, a liquid crystal panel type mask using a liquid crystal material satisfying Δn ≦ 0.1 may be manufactured.
It is possible to provide a liquid crystal mask type exposure marking device that can support high-speed marking.

One of the components constituting the liquid crystal panel type mask is the above-mentioned transparent electrode film (ITO film). This ITO
The light transmittance of the film is related to the wavelength of the light and the ITO film thickness. One example is shown in FIG. Light wavelength λ is 355n
m and 532 nm in terms of relative transmittance. The characteristic has a maximum value and a minimum value with respect to the film thickness at each wavelength, and the laser beam wavelength λ = 35 in this embodiment.
At 5 nm, the maximum relative transmittance is reached at a film thickness of 800 °. By manufacturing a liquid crystal panel type mask with an ITO film thickness that provides the maximum transmittance for the wavelength of light used in this manner, the output of laser light can be used effectively, so that the laser power supply capacity of the marking device is reduced. In addition to the above, there is an effect that the size of the marking device can be reduced.

In this embodiment, the exposure marking on the glass substrate constituting the liquid crystal panel display coated with a photoresist as a photosensitive member has been described. However, as another application example of the present invention, a photoresist is coated as a photosensitive member. Exposure marking can be performed on a color filter constituting the color liquid crystal panel display thus obtained, and the same effect can be obtained.

Further, the present invention can be applied to a method in which a wiring circuit is manufactured by using an exposure system (a photolithography system or the like) in a manufacturing process of an electronic component wiring board. That is, an ultraviolet laser beam such as a third harmonic (wavelength: 355 nm) of a YAG laser or an excimer laser is used as a light source, and a liquid crystal panel type mask is used instead of a metal mask used as a conventional pattern mask. Equivalent performance can be demonstrated. According to this, the circuit pattern can be changed immediately by the liquid crystal panel type mask control device 7 and the liquid crystal panel type mask driving power supply 8 shown in FIG. 1, and a simple exposure system capable of exposing various circuit patterns in a short time is provided. There is an effect that can be done.

As another application example of the present invention in the exposure method, there are two types of laser light: a laser beam that has passed through the pattern information portion of the liquid crystal panel type mask and a laser beam that has the other portion, that is, a laser beam whose pattern information portion has been blanked out. There is a way to use at the same time. FIG. 12 shows the configuration. As described above, there are two types of photoresists that are exposed to ultraviolet light, a positive type resist and a negative type resist. In the case of a positive type resist, the resist portion irradiated with ultraviolet light becomes soft,
The negative resist has a property that the resist portion irradiated with ultraviolet rays is cured. Therefore, the laser beam that has passed through the liquid crystal panel type mask 6 in FIG. 12 is converted by the polarizing beam splitter 9 into an ultraviolet laser beam 2a holding the pattern information of the liquid crystal panel type mask and an ultraviolet laser beam 2a.
The polarization direction is made different, and the fact that the pattern information is divided into the ultraviolet laser beam 2b which is blanked out can be used. Two processing chambers 13a and 13b are provided, and the processing chamber 13a
Exposure member 12a coated with a positive resist inside
And an exposure member 12b coated with a negative resist is disposed inside the processing chamber 13b. Each processing chamber 13a, 13b has a reduced imaging lens 11a, 11b.
The pattern information can be simultaneously transferred to the exposure member 12a coated with the positive resist, and the blank information can be transferred to the exposure member 12b coated with the negative resist. That is, the same mask pattern information can be simultaneously marked on different resist materials. This has the effect of greatly reducing the manufacturing process time when there is a process using a positive resist and a process using a negative resist in the process of manufacturing one product.

In this embodiment, the wavelength λ355 nm, which is the third harmonic of the YAG laser, is used. FIG. 13 shows a schematic configuration thereof. A YAG laser oscillator 50 is provided inside the laser oscillator 1 and oscillates an infrared laser beam (wavelength: 1064 nm) 201. When this laser light is converged by a lens 51 and made incident on a first nonlinear optical crystal element (KTP, BBO, etc.) 52, a second harmonic (a wavelength of 1064 nm) of a fundamental wave (a wavelength of 1064 nm) and a half wavelength thereof (532 nm) are obtained. The laser beam oscillates as a mixed laser beam 202 in which second harmonics are mixed. The polarization directions of these two wavelengths of laser light are orthogonal to each other, the polarization directions are made the same, and the second nonlinear optical crystal elements (LBO, B
BO or the like). At this time, due to the sum frequency effect of the second nonlinear optical crystal element (LBO, BBO, etc.) 54, the fundamental wave (wavelength 1064 nm) and half the wavelength (533
A mixed laser beam 203 in which a second harmonic (2nd harmonic) of 2 nm) is mixed with a third harmonic (3rd harmonic) of ultraviolet light at a wavelength (355 nm) of 1/3 of the fundamental wave. I do.
In the marking device for exposure, the third harmonic is used. Therefore, the optical system 55 including a polarizing beam splitter and a wave plate causes the ultraviolet laser beam 2, which is the third harmonic, and another fundamental wave to be used. It is separated from the harmonic mixed laser light 204. Focusing on the fact that there is a close relationship between the output of the fundamental wave and the output of the second harmonic mixed laser light 204 and the output of the third harmonic, the mixed laser light 204 is measured by the output measuring sensor 56. This signal is taken into the control device 57 and fed back to the YAG laser power supply device 58 to control the output stabilization of the third harmonic ultraviolet laser light 2. Thus, up to now, beam splitting of the third-harmonic ultraviolet laser beam 2 was performed to measure a part of the laser output, and output control was performed. With this method, all of the third-harmonic laser output was used. There is an effect that can be done. Of course, the same effect can be obtained by further separating the mixed laser beam 204 into a fundamental wave and a second harmonic and monitoring the laser output of the third harmonic.

[0034]

According to the above-described liquid crystal mask type exposure marking apparatus of the present invention, a light source for exposure is an ultraviolet laser oscillator, and a polarizing beam splitter is arranged at the subsequent stage of the liquid crystal panel type mask. The ultraviolet laser light that has passed through the mask pattern and the other ultraviolet laser light are separated by the polarizing beam splitter, and the ultraviolet laser light that has passed through the mask pattern separated by the polarizing beam splitter is subjected to a reduction imaging optical system. It is possible to switch the mask pattern in a short time because the marking is performed on the object through the exposure, and since the energy density of the exposure can be increased because of the ultraviolet laser beam, the exposure marking can be performed. This has the effect of shortening the processing time and enabling clear marking.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a liquid crystal mask type exposure marking apparatus of the present invention.

FIG. 2 is a partially broken perspective view showing a general structure of a TFT type liquid crystal display.

FIG. 3 is a sectional view showing a liquid crystal panel type mask employed in an embodiment of the liquid crystal mask type exposure marking apparatus of the present invention.

FIG. 4 is a diagram showing a linearly polarized ultraviolet laser beam having a wavelength of 355 nm, which is a third harmonic of a YAG laser according to an embodiment of the present invention, which is incident on a liquid crystal panel type mask when no voltage is applied to a pixel electrode; It is a figure which shows the difference of a polarization direction.

FIG. 5 is a graph showing a relationship between a laser beam when a voltage is applied to a pixel electrode when a linearly polarized ultraviolet laser beam having a wavelength of 355 nm and a third harmonic of a YAG laser according to an embodiment of the present invention is incident on a liquid crystal panel type mask; It is a figure which shows the difference of a polarization direction.

FIG. 6 is a diagram showing characteristics of transmittance with respect to an applied voltage of laser light in one embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a relationship between a liquid crystal twist angle and a contrast of a liquid crystal panel type mask in one embodiment of the present invention.

FIG. 8 shows a laser beam wavelength of 355n in one embodiment of the present invention.
m, liquid crystal molecule twist angle Φ = 2 of liquid crystal panel type mask
FIG. 14 is a characteristic diagram showing a calculation result of a relative transmittance to Δn · d of the liquid crystal panel type mask when no voltage is applied to the liquid crystal panel type mask at 40 °.

FIG. 9 is a characteristic diagram showing a calculation result of Δn · d with respect to a liquid crystal twist angle of a liquid crystal panel type mask in one embodiment of the present invention.

FIG. 10 is a characteristic diagram showing a relationship between a liquid crystal layer gap length and a response time of a liquid crystal panel type mask in one embodiment of the present invention.

FIG. 11 is a characteristic diagram showing a relationship between a relative transmittance and an ITO film thickness of a liquid crystal panel type mask in one embodiment of the present invention.

FIG. 12 is a configuration diagram showing another embodiment of the liquid crystal mask type exposure marking apparatus of the present invention.

FIG. 13 is a configuration diagram showing an embodiment for stabilizing and controlling a laser output when the liquid crystal mask type exposure marking apparatus of the present invention is implemented.

FIG. 14 is a configuration diagram showing a conventional exposure marking device.

[Explanation of symbols]

1: laser oscillator, 2, 2a, 2b: ultraviolet laser light,
DESCRIPTION OF SYMBOLS 3 ... Optical shutter, 4 ... 1/2 wavelength plate, 5 ... Laser beam magnifying lens system, 6 ... Liquid crystal panel type mask, 7 ... Liquid crystal panel type mask control device, 8 ... Liquid crystal panel type mask drive power supply, 9 ... Polarized beam Splitter, 10 ... Reflector, 11 ...
Reduction imaging lens, 12: glass substrate for liquid crystal display, 12a, 12b: exposure member, 13, 13a, 13b
... Processing chamber, 30a, 30b ... Glass substrate, 31, 32 ...
Pixel electrode films, 33a, 33b: Alignment film, 35: Spacer, 50: YAG laser oscillator, 51: Lens, 52:
First nonlinear optical crystal elements, 53, 55 ... optical system, 54
... a second nonlinear optical crystal element, 56 ... an output measurement sensor,
57: control device, 58: YAG laser power supply device, 201
... infrared laser light, 202, 203, 204 ... mixed laser light.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsumi Kondo, Inventor 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Shinichi Komura 7-1, Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Hitachi Research Laboratory, Hitachi, Ltd.

Claims (11)

[Claims] 1. A light source for exposure, a liquid crystal panel type mask for forming light from the light source into a predetermined exposure pattern, and a light beam passing through the liquid crystal panel type mask and formed on the predetermined exposure pattern. In a liquid crystal mask type exposure marking device having a reduced image forming optical system for performing exposure marking by forming an image on an exposure object, while the light source for exposure is an ultraviolet laser oscillator,
A polarizing beam splitter is disposed at the subsequent stage of the liquid crystal panel type mask, and the ultraviolet laser light that has passed through the mask pattern of the liquid crystal panel type mask and the other ultraviolet laser light are separated by the polarizing beam splitter, and the polarized light beam is split. A liquid crystal mask type exposure marking apparatus, wherein the object to be exposed is marked by irradiating an ultraviolet laser beam having passed through a mask pattern separated by a splitter via the reduction image forming optical system. 2. An ultraviolet laser oscillator, a half-wave plate for rotating ultraviolet laser light from the ultraviolet laser oscillator in a predetermined polarization direction, and ultraviolet light rotated in a predetermined polarization direction by the half-wave plate. A laser beam magnifying lens system for magnifying the laser light, a liquid crystal panel type mask for forming an ultraviolet laser beam magnified by the laser beam magnifying lens system into a predetermined exposure pattern, and a mask pattern of the liquid crystal panel type mask. A polarizing beam splitter for separating ultraviolet laser light from other ultraviolet laser light, and a reduction imaging optical system for irradiating the object with ultraviolet laser light that has passed through the mask pattern separated by the polarizing beam splitter to perform marking And a liquid crystal mask type exposure marking device comprising: 3. An ultraviolet laser oscillator, a half-wave plate for rotating ultraviolet laser light from the ultraviolet laser oscillator in a predetermined polarization direction, and ultraviolet light rotated in a predetermined polarization direction by the half-wave plate. A laser beam magnifying lens system for magnifying the laser light, a liquid crystal panel type mask for forming an ultraviolet laser beam magnified by the laser beam magnifying lens system into a predetermined exposure pattern, and a mask pattern of the liquid crystal panel type mask. A polarizing beam splitter for separating ultraviolet laser light from other ultraviolet laser light, and a reduction imaging optical system for irradiating the object with ultraviolet laser light that has passed through the mask pattern separated by the polarizing beam splitter to perform marking The liquid crystal panel type mask is composed of dot-shaped liquid crystal pixels, and the liquid crystal molecule initial setting of the liquid crystal panel type mask is provided. A liquid crystal mask type exposure marking device, wherein the twist angle is 180 to 270 degrees. 4. A liquid crystal mask type exposure marking apparatus according to claim 3, wherein the gap thickness d (μ) of the liquid crystal layer of the liquid crystal panel type mask in the wavelength region of the ultraviolet laser light.
m) and the refractive index anisotropy Δn of the liquid crystal Δn · d is 0.4.
A liquid crystal mask type exposure marking device, characterized in that the thickness is in the range of 5 to 0.75 (μm). 5. A liquid crystal mask type exposure marking apparatus according to claim 3, wherein the refractive index anisotropy Δn of the liquid crystal in the wavelength region of said ultraviolet laser beam is 0.1 or less. Marking device. 6. The liquid crystal mask type exposure marking apparatus according to claim 1, wherein the laser beam from the ultraviolet laser oscillator is a third harmonic of a Nd: YAG laser. 7. The liquid crystal mask type exposure marking apparatus according to claim 1, wherein the laser beam from the ultraviolet laser oscillator is an excimer laser. 8. A liquid crystal mask type exposure marking apparatus according to claim 1, wherein said object to be exposed is a color filter substrate constituting a liquid crystal display coated with a photoresist material. Mask type exposure marking device. 9. A liquid crystal mask exposure marking apparatus according to claim 1, wherein said object to be exposed is an electronic component wiring board coated with a photoresist material. apparatus. 10. An ultraviolet laser oscillator, a half-wave plate for rotating ultraviolet laser light from the ultraviolet laser oscillator in a predetermined polarization direction, and ultraviolet light rotated in a predetermined polarization direction by the half-wave plate. A laser beam magnifying lens system for magnifying the laser light, a liquid crystal panel type mask for forming an ultraviolet laser beam magnified by the laser beam magnifying lens system into a predetermined exposure pattern, and a mask pattern of the liquid crystal panel type mask. A polarizing beam splitter for separating the ultraviolet laser light from the other ultraviolet laser light, and a first laser beam for irradiating the first object with the ultraviolet laser light having passed through the mask pattern separated by the polarizing beam splitter for marking. And a second laser beam that does not pass through the mask pattern separated by the polarizing beam splitter. Second marking by irradiating the light thereof
A liquid crystal mask type exposure marking apparatus, comprising: 11. A YAG laser oscillator for oscillating an infrared laser beam, and a laser beam from the YAG laser oscillator is converged and incident, and oscillates a laser beam in which a fundamental wave and a second harmonic having a half wavelength thereof are mixed. A first non-linear optical crystal element, an optical system for converging the same laser beam from the first non-linear optical crystal element with the same polarization direction, and a mixed laser beam converged by the optical system, A second nonlinear optical crystal element that oscillates a laser beam in which a wave is mixed with a second harmonic and a third harmonic that is ultraviolet light at a wavelength of １ ／ of the fundamental wave, and the second nonlinear optical crystal An optical system for separating the mixed laser light from the element into a third harmonic ultraviolet laser light and another fundamental and second harmonic mixed laser, and a third harmonic ultraviolet laser separated by the optical system Rotating light in a predetermined polarization direction 1 A two-wavelength plate, a laser beam expanding lens system for expanding the ultraviolet laser light rotated in a predetermined polarization direction by the half-wavelength plate, and a predetermined exposure to the ultraviolet laser light expanded by the laser beam expanding lens system A liquid crystal panel type mask to be formed into a pattern, a polarizing beam splitter for separating ultraviolet laser light passing through the mask pattern of the liquid crystal panel type mask from other ultraviolet laser light, and a mask pattern separated by the polarizing beam splitter A reduction imaging optical system for irradiating an object to be exposed with an ultraviolet laser beam having passed therethrough for marking, a sensor for measuring an output of a mixed laser of a fundamental wave and a second harmonic separated by the optical system, and the sensor And a control device for taking in a signal from the YAG laser oscillator and feeding it back to the power supply of the YAG laser oscillator to control the output of the third harmonic. Liquid crystal mask type exposure marking device, wherein the door.