JP2011123271A - Method for manufacturing display device, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce periodical appearance unevenness in a liquid crystal display panel having an insulating layer formed by exposing and developing a photosensitive insulating film. <P>SOLUTION: In a manufacturing process of a display panel including a display area of a plurality of pixels, the display device has a step of forming an insulating layer formed by exposing and developing the photosensitive insulating film, wherein the exposure of the photosensitive insulating film is performed by repeating a first operation for moving a region which can be exposed once in a first direction and a second operation for moving a region which can be exposed once in a second direction orthogonal to the first direction while overlapping the regions which can be exposed once by a prescribed width, an outside region of the overlapped region where the region which can be exposed once passes twice or more in a region which is not exposed is irradiated with light having the same intensity as the sum total intensity of leakage light with which the overlapped region is irradiated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a display device manufacturing method and a display device, and more particularly to a technique effective when applied to a manufacturing method of a liquid crystal display panel having an insulating layer obtained by exposing and developing a photosensitive material film.

  The method for manufacturing a liquid crystal display panel includes a step of manufacturing a TFT substrate, a step of manufacturing a counter substrate, and a step of bonding the TFT substrate and the counter substrate and encapsulating a liquid crystal layer. At this time, in the process of manufacturing the TFT substrate, the process of exposing and developing the photosensitive material film is performed a plurality of times.

  The exposure and development of the photosensitive material film in the process of manufacturing the TFT substrate is usually performed by, for example, a process of forming a scanning signal line, a process of forming a video signal line, a process of forming a pixel electrode, and a semiconductor of a TFT element. It is performed in a step of forming a layer. The exposure and development of the photosensitive material film performed at this time are steps performed to form a mask (etching resist) for etching the conductive film or the semiconductor film. Therefore, the mask obtained by exposing and developing the photosensitive material film is usually removed after etching.

  Further, the step of forming the TFT substrate includes a step of forming a contact hole (through hole) for connecting, for example, the source electrode of the TFT element and the pixel electrode in the insulating layer formed on the insulating substrate. . The process of forming this contact hole has been conventionally formed by etching using a mask obtained by exposing and developing a photosensitive material film.

  However, in recent TFT substrate manufacturing methods, a method of forming the insulating layer having the contact hole with, for example, a photosensitive organic insulating film is applied. In this method, it is possible to form the insulating layer having the contact hole simply by exposing and developing the photosensitive organic insulating film, and effects such as shortening the formation time and saving of material costs can be obtained.

  Conventionally, when exposing a photosensitive material film in a method for manufacturing a TFT substrate, a photomask is generally used.

  However, when manufacturing a liquid crystal display panel based on a set of layout data, for example, it is often manufactured in parallel on a plurality of manufacturing lines. Therefore, when exposing the photosensitive material film using a photomask, at least the same number of photomasks as the production line are required.

  In addition, when exposing a photosensitive resist using a photomask, for example, if layout data is changed, it is necessary to recreate the photomask based on the changed layout data. In particular, in recent liquid crystal display panels, TFT elements have been miniaturized due to high definition and the like, and for example, high precision is required for the formation position and dimensions of the contact holes. Therefore, if the contact hole is formed in a different position or size, and the shift affects the operation of the liquid crystal display panel, for example, a photomask used in exposure performed when an insulating layer having the contact hole is formed. Need to be remade.

  For these reasons, in recent manufacturing methods of liquid crystal display panels, a method of exposing a photosensitive material film without using a photomask (hereinafter referred to as maskless exposure) has been studied. As maskless exposure, for example, a method is known in which exposure is performed using a light modulation component (spatial light modulation element) that generates a pattern of light to be irradiated onto a photosensitive material film by numerical control based on layout data (for example, , See Patent Document 1).

JP 2005-294373 A

  For example, the light modulation component used in the maskless exposure needs to control the generated light pattern in units of 0.5 μm or less. Therefore, considering the controllability of the light modulation component, the area that can be exposed at one time by maskless exposure is much smaller than the entire exposure target area of the photosensitive material film (that is, the area of the mother glass). Therefore, when the photosensitive material film is exposed by maskless exposure, for example, the first operation in which exposure is performed while moving the region that can be exposed at a time in the first direction, and the region that can be exposed at a time is the first. The entire photosensitive material film is exposed by repeating the second operation of moving in the second direction orthogonal to the direction.

  In addition, the photosensitive material film exposure method in which the first operation and the second operation as described above are repeated, in other words, the photosensitive material film is divided into a plurality of band-like regions, It can be said that the exposure is performed sequentially for each region. Therefore, in such a photosensitive material film exposure method, an area that can be exposed at one time is twice at the boundary between the two strip-shaped regions so that an unexposed region does not occur between two adjacent strip-shaped regions. An overlapping area is provided.

  However, as described above, in the case where an overlapping area where an area that can be exposed at a time passes twice is provided at the boundary between two strip-shaped areas, it corresponds to the overlapping area on the surface of the pattern obtained by development. There is a step in the position. Since the overlapping region is provided at the boundary between two adjacent belt-like regions, the step is generated in a striped manner at regular intervals with the width of the belt-like region (dimension in the second direction), for example.

  That is, when a positive type photosensitive organic insulating film is exposed and developed to form an insulating layer having a contact hole, a step (photosensitive organic insulating film) is formed on the surface of the insulating layer (photosensitive organic insulating film) formed after the development. Specifically, grooves) are formed in a striped pattern.

  The interval between the grooves formed in stripes on the surface of the insulating layer is approximately equal to the width of the region that can be exposed at one time (dimension in the second direction), and is, for example, about 1 mm to 50 mm.

  Moreover, although the groove | channel produced in the striped form on the surface of this insulating layer does not affect the operation | movement of a liquid crystal display device, there exists a problem that a striped external appearance nonuniformity generate | occur | produces, for example, when a liquid crystal display device is observed. The striped appearance unevenness is caused by, for example, the influence of light reflection or refraction at a groove portion formed on the surface of the insulating layer. Therefore, in such a liquid crystal display panel, for example, striped unevenness having a period larger than the pixel size may occur in the displayed video or image.

  An object of the present invention is to provide a technique capable of reducing periodic appearance irregularities in a liquid crystal display panel having an insulating layer formed by exposing and developing a photosensitive insulating film, for example.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The outline of typical inventions among the inventions disclosed in the present application will be described as follows.

  (1) A display panel having a display region including a plurality of pixels, the display panel having a plurality of insulating layers, and one or more insulating layers of the plurality of insulating layers have through holes. And a display device in which a plurality of grooves are arranged in stripes at an interval larger than the size of the pixel at an interface with another insulating layer, and the groove of the insulating layer has a depth A display device having a thickness of 10 nm or less.

  (2) The display device according to (1), wherein the groove of the insulating layer has a depth of 5 nm or less.

  (3) The display device according to (1), wherein the display panel is a liquid crystal display panel.

  (4) In the process of manufacturing a display panel having a display area composed of a plurality of pixels, the method includes a step of forming an insulating layer formed by exposing and developing the photosensitive insulating film. The exposure of the photosensitive insulating film is performed once. Repeating a first operation for moving the region that can be exposed in a first direction and a second operation for moving the region that can be exposed at a time in a second direction orthogonal to the first direction, And a method of manufacturing a display device, wherein the regions that can be exposed at a time are overlapped by a predetermined width, wherein the photosensitive material film is exposed to a region that is not exposed at one time. The manufacturing method of the display apparatus which irradiates the light of the same intensity | strength as the total amount of the intensity | strength of the leakage light irradiated to the said overlapping area with respect to the area | region outside the overlapping area which passes twice or more.

  (5) In the process of manufacturing a display panel having a display region composed of a plurality of pixels, the method includes a step of forming an insulating layer formed by exposing and developing the photosensitive insulating film. The exposure of the photosensitive insulating film is performed once. Repeating a first operation for moving the region that can be exposed in a first direction and a second operation for moving the region that can be exposed at a time in a second direction orthogonal to the first direction, In addition, a method of manufacturing a display device is performed by overlapping a region that can be exposed at a time by a predetermined width, and the exposure of the photosensitive material film is performed on the region that is not exposed to light that is irradiated to the region that is exposed. The total amount of light intensity irradiated to the overlapping area where the area that can be exposed at one time is irradiated twice or more of the unexposed area that is irradiated with light having a sufficiently small intensity compared to the intensity. , For the area outside the overlap area Method of manufacturing a display device to equalize the intensity of the irradiated light.

  (6) In the method for manufacturing a display device according to (4) or (5), the region that can be exposed at one time has a region that is always irradiated with only the leakage light on an outer peripheral portion thereof. Method.

  (7) In the method for manufacturing a display device according to (4) or (5), exposure of the photosensitive material film is performed during the first operation, and the region that can be exposed at one time is A method of manufacturing a display device, wherein the dimension in the second direction is larger than the dimension of the pixel.

  (8) In the method for manufacturing a display device according to (4) or (5), the photosensitive material film is exposed by numerical control based on drawing data created based on layout data prepared in advance. A manufacturing method of a display device, which is performed using an exposure device having a light modulation element that generates a pattern of light irradiated on a film.

  According to the display device and the manufacturing method of the display device of the present invention, for example, periodic appearance unevenness in a liquid crystal display device including a liquid crystal display panel having an insulating layer formed by exposing and developing a photosensitive insulating film is reduced. can do.

It is a schematic plan view which shows an example of the plane structure of the pixel in the liquid crystal display panel concerning this invention. It is a schematic cross section which shows an example of the cross-sectional structure in the A-A 'line of Fig.1 (a). It is a schematic plan view which shows an example of the exposure procedure of maskless exposure. It is the model top view which expanded and showed area | region AR1 of Fig.2 (a). It is a schematic cross section which shows an example of the exposure on the B-B 'line | wire of FIG.2 (b). It is a schematic plan view which shows an example of the exposure method of the boundary of two adjacent strip | belt-shaped area | regions. It is a schematic diagram which shows an example of the light quantity when not exposing the position of the C-C 'line of FIG.2 (d). It is a schematic diagram which shows an example of the light quantity when exposing the position of the C-C 'line | wire of FIG.2 (d). It is a schematic cross section which shows an example of a problem when forming the 2nd insulating layer using the conventional maskless exposure. It is a schematic diagram which shows an example of the relationship between the depth of the groove | channel which arises on the surface of an insulating layer, and the level of the nonuniformity which arises in a liquid crystal display panel. It is a schematic diagram for demonstrating the exposure method of the photosensitive material film | membrane of Example 1 by this invention. 10 is a schematic diagram for explaining an example of a modification of the exposure method of Embodiment 1. FIG. FIG. 5 is a schematic graph showing an example of a phenomenon that can occur in the exposure method shown in FIG. 4. FIG. 6 is a schematic graph showing an example of a phenomenon that can occur in the exposure method shown in FIG. 5. It is a schematic plan view which shows another example of the exposure method of the border of the strip | belt-shaped area | region in the conventional maskless exposure. It is a schematic diagram which shows an example of the light quantity when not exposing the position of the D-D 'line of Fig.7 (a). It is a schematic diagram which shows an example of the light quantity when exposing the position of the D-D 'line of Fig.7 (a). It is a schematic diagram for demonstrating the exposure method of the photosensitive material film | membrane of Example 2 by this invention. 6 is a schematic diagram for explaining a first modification of the exposure method of Embodiment 2. FIG. 6 is a schematic diagram for explaining a second modification of the exposure method of Embodiment 2. FIG. 10 is a schematic diagram for explaining another modification of the exposure method of Embodiment 1. FIG. 10 is a schematic diagram for explaining still another modification of the exposure method of Embodiment 1. FIG.

Hereinafter, the present invention will be described in detail together with embodiments (examples) with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same function are given the same reference numerals and their repeated explanation is omitted.

FIG. 1A and FIG. 1B are schematic views showing an example of a schematic configuration of a pixel in a liquid crystal display panel according to the present invention.
FIG. 1A is a schematic plan view showing an example of a planar configuration of a pixel in a liquid crystal display panel according to the present invention. FIG. 1B is a schematic cross-sectional view showing an example of a cross-sectional configuration taken along line AA ′ in FIG.

  The present invention relates to a method for manufacturing a display panel having an insulating layer obtained by exposing and developing a photosensitive insulating film. In this specification, a liquid crystal display panel manufacturing method is given as an example of such a display panel manufacturing method. In this specification, an IPS active matrix TFT liquid crystal display panel (hereinafter simply referred to as a liquid crystal display panel) is given as an example of a liquid crystal display panel.

  Furthermore, the configuration and operation of the liquid crystal display panel exemplified in this specification are well known. Therefore, in the present specification, a detailed description of the configuration and operation of the liquid crystal display panel that are not directly related to the present invention is omitted.

  For example, as shown in FIGS. 1A and 1B, the liquid crystal display panel includes a TFT substrate 1, a counter substrate 2, a liquid crystal layer 3, a first polarizing plate 4, and a second polarizing plate 5. Have.

  The TFT substrate 1 includes a first insulating substrate 6 such as a glass substrate, and a first thin film stack (not shown) formed on the first insulating substrate 6. The first thin film stack includes, for example, the scanning signal line 7, the first insulating layer 8, the semiconductor layer 9 of the TFT element, the video signal line 10, the source-drain electrode 11, the second insulating layer 12, and the common electrode 13. , A third insulating layer 14, a pixel electrode 15, and a first alignment film 16.

  At this time, as shown in FIG. 1B, the pixel electrode 15 includes a through hole 22 a formed in the second insulating layer 12 and a through hole 22 b (contact hole) formed in the third insulating layer 14. Thus, the source-drain electrode 11 is connected. The second insulating layer 12 and the third insulating layer 14 in the liquid crystal display panel according to the present invention are formed by exposing and developing a photosensitive insulating film, respectively.

  On the other hand, the counter substrate 2 includes a second insulating substrate 17 such as a glass substrate, and a second thin film stack (not shown) formed on the second insulating substrate 17. The second thin film stack includes, for example, a black matrix 18, a color filter 19, a planarizing layer 20, a second alignment film 21, and the like.

  The method for manufacturing a liquid crystal display panel includes a step of forming a TFT substrate 1, a step of forming a counter substrate 2, a step of bonding the TFT substrate 1 and the counter substrate 2 and enclosing a liquid crystal layer 3, and a first polarizing plate. 4 and a step of bonding the second polarizing plate 5 together.

  In addition, the present invention mainly relates to a step of forming the TFT substrate 1 among these steps, for example, an exposure method when forming the second insulating layer 12 and the third insulating layer 14. Therefore, in this specification, first, a conventional method for forming the second insulating layer 12 and the third insulating layer 14 will be briefly described.

  When the second insulating layer 12 is formed, first, for example, a positive photosensitive layer is formed on the first insulating layer 8 on which the semiconductor layer 9, the video signal line 10, the source-drain electrode 11 and the like are formed. An organic insulating film is formed (film formation). Next, the photosensitive organic insulating film is exposed, and light is irradiated only to a region where the through hole 22a is formed, so that the region is exposed. Then, when it develops and performs baking (heat processing) etc., the 2nd insulating layer 12 which has the through-hole 22a will be obtained.

  The third insulating layer 14 is also formed by the same method as the second insulating layer 12.

  The exposure performed in the step of forming the second insulating layer 12 and the step of forming the third insulating layer 14 has been conventionally performed using a photomask. However, when a photomask is used, for example, when the formation positions and dimensions of the through holes 22a and 22b are shifted beyond an allowable range or the formation positions and dimensions are changed, it is necessary to recreate the photomask each time. is there. Therefore, in the exposure method using a photomask, there is a problem that it is difficult to flexibly cope with correction or change of the formation positions and dimensions of the through holes 22a and 22b.

  For this reason, application of an exposure method that does not use a photomask (maskless exposure) is being studied in recent liquid crystal display panel manufacturing methods. Maskless exposure is an exposure method that uses a light modulation member that generates a light pattern (that is, an exposure pattern) for irradiating a photosensitive insulating film by numerical control based on drawing data created based on layout data instead of a photomask. is there. That is, in the maskless exposure, the pattern of light to be irradiated can be changed only by changing the numerical value of the drawing data (layout data). Therefore, if maskless exposure is applied to the exposure performed in the step of forming the second insulating layer 12 and the step of forming the third insulating layer 14, it is possible to correct or change the formation positions and dimensions of the through holes 22a and 22b. Can respond flexibly.

  However, when maskless exposure is applied to exposure performed in the step of forming the second insulating layer 12 or the step of forming the third insulating layer 14, the conventional maskless exposure is, for example, as described below. Problems arise.

2A to 2G are schematic diagrams for explaining an example of the principle of maskless exposure and a problem in conventional maskless exposure.
FIG. 2A is a schematic plan view showing an example of an exposure procedure of maskless exposure. FIG. 2B is a schematic plan view showing the area AR1 of FIG. FIG.2 (c) is a schematic cross section which shows an example of the exposure on the BB 'line | wire of FIG.2 (b). FIG. 2D is a schematic plan view showing an example of an exposure method for the boundary between two adjacent band-like regions. FIG. 2E is a schematic diagram showing an example of the amount of light when the position of the CC ′ line in FIG. 2D is not exposed. FIG. 2F is a schematic diagram illustrating an example of the amount of light when the position of the CC ′ line in FIG. FIG. 2G is a schematic cross-sectional view showing an example of a problem when the second insulating layer is formed using conventional maskless exposure.

  In the light modulation component used in the maskless exposure, for example, light amount control elements for controlling the light amount (intensity) of light applied to the photosensitive insulating film are arranged in a line or a matrix. Then, the drawing data is used to control the state of each light quantity control element, thereby forming a two-dimensional pattern of light to be applied to the photosensitive insulating film.

  In the exposure performed in the step of forming the second insulating layer 12 and the step of forming the third insulating layer 14, the pattern of light applied to the photosensitive insulating film needs to be controlled in units of 0.5 μm, for example. . Therefore, considering the controllability of the light modulation component, the area that can be exposed at one time by maskless exposure (hereinafter referred to as the exposure area) is much smaller than the entire exposure target area of the photosensitive insulating film.

Therefore, when exposing the photosensitive insulating film by maskless exposure, for example, as shown in FIG. 2A, the position of the exposure region ER on the photosensitive insulating film 23 is set in the first direction (v-axis direction). The entire photosensitive insulating film 23 is repeated by repeating the first operation of exposing while moving and the second operation of moving the exposure region ER in the second direction (u-axis direction) orthogonal to the first direction. To expose. In other words, this exposure method can be said to be a method in which the photosensitive insulating film 23 is divided into a plurality of strip-shaped regions and the strip-shaped regions are sequentially exposed. At this time, the width W _Q (dimension in the u-axis direction) of the belt-like region Q exposed in one first operation is, for example, about 1 mm to 50 mm. At this time, in the first operation and the second operation, for example, the exposure region ER (light modulation component) is fixed, and the substrate 24 on which the photosensitive insulating film 23 is formed is moved in the v-axis direction and u. It is common to move in the axial direction.

  When manufacturing a liquid crystal display panel (TFT substrate 1), it is common to use a method of collectively manufacturing a plurality of TFT substrates 1 using a single mother glass, which is called multi-chamfering. In this case, there are two relations between the x-axis direction and the y-axis direction in the TFT substrate 1 shown in FIG. 1A and the u-axis direction and the v-axis direction when the photosensitive insulating film 23 is exposed. . That is, the x-axis direction on the TFT substrate 1 and the u-axis direction when the photosensitive insulating film 23 is exposed are parallel, and the x-axis direction on the TFT substrate 1 and v when the photosensitive insulating film 23 is exposed. There are two ways when the axial direction is parallel.

Focusing on the first operation of one time, the band-like region Q exposed by the operation is divided into a large number of fine band-like regions R as shown in FIGS. 2B and 2C, for example. Then, the fine band-like region R is exposed independently. At this time, the width W _R (the dimension in the u-axis direction) of the fine strip region R is, for example, about 0.5 μm.

  At this time, the light quantity control elements 25a of the light modulation component 25 are arranged in the direction of movement in the second operation, that is, in the short side direction (u-axis direction) of the photosensitive insulating film 23, for example. Therefore, by controlling the state of each light amount control element 25a (the amount of light to be irradiated), as shown in FIG. 2C, the exposed region ER is exposed to the exposed region and the unexposed region. And can make. Note that the photosensitive insulating film 23 shown in FIG. 2C is a region where a portion with a dot pattern is exposed by exposure, and a white portion is a region where it is not exposed.

  In addition, the state of each light quantity control element 25a is controlled by drawing data created based on the layout data. This drawing data is numerical data, and, for example, the position of a region where light is irradiated and the amount of light to be irradiated are designated.

Such maskless exposure can be said to be a method in which the photosensitive insulating film 23 is divided into a plurality of band-like regions Q and the respective regions Q are sequentially exposed as described above. Therefore, in such maskless exposure, it is necessary to prevent an unexposed region from occurring at the boundary between two adjacent band-like regions Q. Therefore, in such maskless exposure, for example, as shown in FIG. 2D, the width W _Q of the strip-like region Q exposed in one first operation is set to be larger than the width W _ER of the exposure region ER. narrowly, overlapping areas of width W _CO1 to the boundary BL _Q of two adjacent strip-like regions Q, i.e. provide a region that can be exposed region ER passes twice at a time. FIG. 2D is an enlarged view of the area AR2 in FIG. Further, in FIG. 2 (d), the order to distinguish between the two strip-like regions Q adjacent across the center of the boundary BL _Q, is denoted by the letter n and n + 1 subject to the code Q.

  By the way, when the photosensitive insulating film 23 is exposed by such maskless exposure, the light amount control element 25a is usually irradiated with light having a sufficient light amount (intensity) to expose the photosensitive insulating film 23. There are two states, a state of performing light and a state of not irradiating light.

That is, when the position of the CC ′ line shown in FIG. 2D is not exposed, the right belt region Q _{n + 1} is also exposed when the left belt region Q _n of the boundary BL_ {Q} is exposed. Also during the exposure, the light quantity control element 25a corresponding to the position is turned off (the light is not irradiated).

However, when the photosensitive insulating film 23 is exposed using the light modulation component 25, for example, a slight amount of light leaks from the light amount control element 25a in an off state (a state where no light is irradiated), and the photosensitive insulating film 23 is irradiated. Therefore, Figure 2 when not sensitive to the position of the line C-C 'shown (d), the intensity IR _n of the light irradiated when exposing a strip-shaped region Q _n of the left, right band-like region Q _{n + 1} the intensity of the light irradiated when exposing the IR n _{+ 1,} and the relationship between the total IR _T of the intensity of light applied to the photosensitive insulating film 23, for example, bold lines P1, P2 shown in FIG. 2 (e) , P3.

Incidentally, in FIG. _{2 (e), IR n,} IR n + 1, and IR _T are each a relative value of the intensity of light, the photosensitive insulating film 23 as a necessary and sufficient amount of light to cause the photosensitive Yes. The horizontal axis Cu represents the coordinates in the u-axis direction, and the section from the coordinates U1 to U4 corresponds to the section of the line CC ′ in FIG.

That is, when not sensitive to the position of the line C-C 'shown in FIG. 2 (d), two adjacent strip-like regions Q _n, from the overlap region (coordinates U2 to the coordinates U3 in Q n _{+ 1} boundary BL _Q In the section (2), light having the intensity IL _OFF (hereinafter referred to as leakage light) is irradiated twice due to light leakage as described above, so that the exposure amount is about twice that of the outside of the overlapping region.

The intensity IL _{OFF of the} leakage light is about 1% of the amount of light necessary and sufficient for exposing the photosensitive insulating film 23. For this reason, even if the photosensitive insulating film 23 is irradiated with leakage light having intensity IL _OFF , the surface is only slightly exposed.

  However, the exposed amount (depth) of the photosensitive insulating film 23 increases (becomes deeper) as the intensity (light amount) of the irradiated light increases. For this reason, as shown in FIG. 2E, if there is a portion where the intensity of the partially irradiated light is increased, the amount of exposure is increased only at that portion. Therefore, when the photosensitive material film 23 is a positive type, a groove having a step reflecting the difference in the intensity of the leaked light is formed on the surface of the insulating layer obtained by development after exposure.

Incidentally, when exposing the position of the CC ′ line shown in FIG. 2D, the intensity IR _{n of} light irradiated when exposing the left band-like region Q _n and the right band-like region Q _{n + 1.} the intensity of the light irradiated when exposing the IR n _{+ 1,} and the relationship of the total amount IR _T of the intensity of light applied to the photosensitive insulating film 23, for example, a thick line P1 shown in FIG. 2 (f) ', The relationship is P2 ′, P3 ′.

Incidentally, in FIG. _{2 (f), IR n,} IR n + 1, and IR _T are each a relative value of the intensity of light, the photosensitive insulating film 23 as a necessary and sufficient amount of light to cause the photosensitive Yes. The horizontal axis Cu represents the coordinates in the u-axis direction, the section from the coordinates U1 to the coordinates U4 corresponds to the section of the line CC ′ in FIG. 2D, and the section from the coordinates U2 to the coordinates U3. It corresponds to the overlapping area.

That is, if for sensitizing the position of the line C-C 'shown in FIG. 2 (d), two adjacent strip-like regions Q _n, from the overlap region (coordinates U2 to the coordinates U3 in Q n _{+ 1} boundary BL _Q The total amount of light emitted in the section (1) is increased by the intensity IL _OFF compared to the outside of the overlapping region due to the light leakage as described above. However, the region of the photosensitive insulating film 23 where the relative value of the intensity of irradiated light is 1 or greater than 1 is completely exposed regardless of the intensity value. Therefore, in the case where the position of the CC ′ line shown in FIG. 2D is exposed, there is no problem even if the relative value of the total amount of light applied to the overlapping region is 1 or more.

For this reason, a positive photosensitive organic insulating film is used for the second insulating layer 12 of the liquid crystal display panel having the pixels configured as shown in FIGS. 1A and 1B. Further, when the conventional maskless exposure is applied, for example, as shown in FIG. _2G , the groove 26 having a width W _CO1 and a depth d is formed in a stripe pattern on the surface of the second insulating layer 12. To occur. The groove 26 is, therefore occurs at the boundary BL _Q of two adjacent strip-like regions Q, groove spacing 26 will width W _Q of the band-like region Q.

  In addition, as shown in FIG. 2G, when the x-axis direction of the TFT substrate 1 and the u-axis direction when exposing the photosensitive organic insulating film are parallel, the plurality of grooves 26 are formed on the liquid crystal display panel. Are arranged in the direction in which the scanning signal lines 7 extend.

Furthermore, the width W _Q of the belt-like region Q is about 1 mm to 50 mm as described above. On the other hand, the dimension of the pixel in the x-axis direction is about several tens of μm. Therefore, the striped grooves 26 formed on the surface of the second insulating layer 12 are arranged at intervals sufficiently larger than the dimensions of the pixels.

  Further, when the x-axis direction on the TFT substrate 1 and the v-axis direction when the photosensitive organic insulating film is exposed are parallel, the plurality of grooves 26 are directions in which the video signal lines 10 extend in the display area of the liquid crystal display panel. Lined up. Since the dimension in the y-axis direction of the pixel is also about several tens of μm, the striped grooves 26 formed on the surface of the second insulating layer 12 are also arranged at intervals sufficiently larger than the dimension of the pixel. It will be.

  Further, when the third insulating layer 14 is formed, if a positive type photosensitive organic insulating film is used and the conventional maskless exposure is applied, the second insulating layer 14 has a second surface on the surface thereof. The grooves 26 similar to those of the insulating layer 12 are formed in stripes.

  A stripe-shaped groove 26 formed on the surface of the second insulating layer 12 or the third insulating layer 14 formed by using a positive type photosensitive organic insulating film and applying the conventional maskless exposure is a pixel. For example, when the appearance is inspected, it is observed as striped unevenness. As a result of investigations by the inventors of the present application, this striped unevenness is not observed when a video or an image is displayed, but can be observed with the naked eye when not in use. That is, the striped unevenness is considered to have no influence on the display quality at present, but such unevenness occurs when not in use, thereby degrading the quality of the liquid crystal display device. .

  In addition, when such striped unevenness is observed when not in use, for example, when a video or image is displayed with low luminance (low gradation), the displayed video or image is striped. There is a possibility that the unevenness of the shape overlaps and causes the display quality to deteriorate. Furthermore, such striped unevenness mainly occurs when external light is reflected on the surfaces of the second insulating layer 12 and the third insulating layer 14. Therefore, in a reflective or transflective liquid crystal display device, there is a high possibility that the display quality is deteriorated due to such striped unevenness.

  The striped unevenness as described above is not limited to the liquid crystal display panel having the pixels as shown in FIGS. 1A and 1B, and is formed by applying conventional maskless exposure. It occurs in general liquid crystal display panels having an insulating layer.

3 and 4 are schematic views for explaining the method for exposing the photosensitive insulating film of Example 1 according to the present invention.
FIG. 3 is a schematic diagram showing an example of the relationship between the depth of the groove generated on the surface of the insulating layer and the level of unevenness generated in the liquid crystal display panel. FIG. 4 is a schematic diagram for explaining the photosensitive material film exposure method of Example 1 according to the present invention.

  In the liquid crystal display panel having the second insulating layer 12 and the third insulating layer 14 formed by applying maskless exposure, the stripe-shaped unevenness as described above is observed on the surfaces of these insulating layers. This is considered to be because there is a difference in external light reflection luminance between the groove formed in the above and other flat portions. Further, the difference in the external light reflection luminance becomes larger as the grooves on the surfaces of the second insulating layer 12 and the third insulating layer 14 become deeper. Therefore, as the groove on the surface of the second insulating layer 12 or the third insulating layer 14 becomes deeper, the above-described striped unevenness becomes stronger. Therefore, in order to prevent the striped unevenness from being observed, it is desirable to prevent grooves due to maskless exposure from occurring on the surfaces of the second insulating layer 12 and the third insulating layer 14. However, in the case of maskless exposure, as described above, there are an overlapping area where the exposure area ER passes twice and an area where the exposure area ER passes only once, so it is difficult to match the exposure amounts in these areas.

  Therefore, the inventors of the present application first investigated the relationship between the depth d of the groove 26 formed on the surface of the second insulating layer 12 or the third insulating layer 14 and the level of visual judgment of unevenness generated in the liquid crystal display panel. . The result is shown in FIG. FIG. 3 is a graph of the visual judgment level ULV where the horizontal axis is the depth d (nm) of the groove 26 and the vertical axis is uneven. Further, the visual judgment level ULV is less uneven as the numerical value is larger, and is a level at which the unevenness cannot be visually recognized in the case of 4 or 5 (acceptable level). Pass level). Further, the relationship between the numerical value of the visual determination level ULV and the intensity of unevenness is specifically as follows.

  First, when the striped unevenness resulting from maskless exposure cannot be visually recognized, the visual determination level ULV is specifically set to 5 when the scattered light intensity is less than 0.1%. Further, the visual judgment level ULV when the unevenness can be confirmed as the scattered light intensity is 4 if it is 0.1% or more and less than 0.2%, and 3 if it is 0.2% or more and less than 0.4%, If it is 0.4% or more and less than 0.6%, it is set to 2, and if it is 0.6% or more, it is set to 1.

  As can be seen from FIG. 3, when the depth d of the groove 26 formed on the surface of the second insulating layer 12 or the third insulating layer 14 is 10 nm or less, the visual judgment level ULV is 4 or 5, and maskless Unevenness due to exposure is not observed. In particular, when the depth d of the groove 26 is 5 nm or less, the visual determination level ULV is 5, and unevenness due to maskless exposure cannot be visually recognized. Therefore, in the exposure method of Example 1, the target is to make the depth d of the groove 26 resulting from maskless exposure 10 nm or less (preferably 5 nm or less).

  When the positive type photosensitive organic insulating layer is exposed by maskless exposure to form the second insulating layer 12 or the third insulating layer 14, it is necessary to irradiate light with contact holes 22 a and 22 b. It is only the area | region which forms. At this time, light is not irradiated to other portions, but the other portions are irradiated with leakage light as described above.

When the position of the CC ′ line shown in FIG. 2D is not included in the region where the contact holes 22a and 22b are formed, that is, when the leakage light is irradiated to the position, the photosensitive insulation according to the first embodiment. in the exposure method of the membrane, the intensity IR n _{+ 1} of light to be irradiated when the exposure intensity of light IR _n that irradiation when exposing a strip-shaped region Q _n on the left, the right band region Q _{n + 1,} and the photosensitive relationship of the total amount IR _T of the intensity of light applied to sex insulating film 23 is, for example, to be a relationship as shown in thick line P4, P5, P6 shown in FIG.

Incidentally, in FIG. _{4, IR n, IR n +} 1, and IR _T, respectively, the relative value of the intensity of light to be irradiated when exposing a strip-shaped region Q _n on the left, the right band region Q _{n + 1} It represents the relative value of the intensity of light irradiated during exposure and the relative value of the total amount of light intensity irradiated to the photosensitive insulating film 23. The horizontal axis Cu represents the coordinates in the u-axis direction, the section from the coordinates U1 to the coordinates U4 corresponds to the section of the line CC ′ in FIG. 2D, and the section from the coordinates U2 to the coordinates U3. It corresponds to the overlapping area. The relative value IR _n of the intensity of the light, IR n + _1, and IR _T are respectively set to 1 required sufficient quantity of light the photosensitive material film 23 to cause the photosensitive.

That is, when the position of the CC ′ line shown in FIG. 2D is not exposed, in the exposure method of the first embodiment, first, the boundary BL _Q between two adjacent belt-like regions Q _n and Q _{n + 1} is set. The light quantity control element 25a responsible for exposure in a certain overlapping area (section from the coordinate U2 to the coordinate U3) is set so as not to irradiate light so that only leaked light with intensity IL _OFF is irradiated.

In addition, the area outside the overlapping area, that is, the area where the exposure area ER passes only once is irradiated with light having an intensity IL _AO equivalent to twice the intensity IL _OFF of the leakage light. That is, the light quantity control element 25a responsible for exposure of the region where the exposure region ER passes only once is set to a state where light of intensity IL _AO is irradiated.

In this way, the total IR _T of the intensity of light irradiated to the overlap region and the outer region thereof, a constant value IL _AO. For this reason, the intensity of light applied to other regions other than the regions where the contact holes 22a and 22b are formed is substantially constant, and the amount (depth) of light exposure is also substantially constant. Therefore, it is considered that the striped grooves 26 due to maskless exposure do not occur on the surfaces of the second insulating layer 12 and the third insulating layer 14 obtained after development.

However, in actuality, the amount (depth) of light exposure when irradiated with light of intensity IL _OFF twice as in the overlapping region and when irradiated with intensity IL _AO (= 2 × IL _OFF ) once. May cause a difference. Further, the intensity of light irradiated through the light quantity control element 25a varies slightly for each light quantity control element 25a. Therefore, the total amount IR _T of the intensity of the light emitted is, in fact, not the constant value, such as a thick line P6 shown in FIG. 4, in the overlap region, and its outer region, slight differences May occur. Therefore, even when the control as shown in FIG. 4 is performed, a striped groove 26 due to maskless exposure often occurs.

  Therefore, the inventors of the present application, in the process of forming the second insulating layer 12 and the third insulating layer 14 in the process of forming the TFT substrate 1, draw data satisfying the conditions as shown in FIG. Was used to measure the depth d of the groove 26 formed on the surface, and the average value was 8 nm. Moreover, when the liquid crystal display panel using said TFT substrate 1 was produced and the external appearance was test | inspected, the visual determination level ULV of the striped nonuniformity resulting from maskless exposure was 4 (pass level).

  That is, in the exposure method of Example 1, striped grooves 26 due to maskless exposure may occur on the surfaces of the second insulating layer 12 and the third insulating layer 14. However, in the liquid crystal display panel (liquid crystal display device) having the second insulating layer 12 and the third insulating layer 14 formed by applying the exposure method of Example 1, striped unevenness due to the striped grooves 26 is achieved. Will not be observable. Therefore, in the liquid crystal display panel (liquid crystal display device) formed by applying the exposure method of Example 1, it is possible to prevent the appearance quality and display quality from being deteriorated by the striped grooves 26.

  As described above, the liquid crystal display panel (liquid crystal display device) formed by applying the exposure method of Example 1 can prevent the deterioration of the appearance quality and the display quality due to the maskless exposure.

In the first embodiment, the intensity IL _AO of the light radiated to the outside of the overlapping area is mechanically made twice the intensity IL _OFF of the leakage light radiated to the overlapping area. However, the intensity IL _AO of the light radiated to the outside of the overlapping area is not limited to this. For example, the total amount of leakage light radiated to the overlapping area is measured more accurately, and the intensity becomes equal to the total amount. Of course, it may be set to. Furthermore, the intensity IL _AO of the light radiated to the outside of the overlapping region is measured, for example, by measuring the amount of decrease in the thickness of the overlapping region when developed, and the amount of decrease in the thickness outside the overlapping region is measured in the overlapping region. Of course, the strength may be set equal to the amount of decrease.

  FIG. 5 is a schematic diagram for explaining an example of a modification of the exposure method of the first embodiment.

As an example of the exposure method of the first embodiment, the method shown in FIG. 4 is the intensity IL of the leaked light that irradiates the overlapping area over the entire area designated not to be exposed in the layout data that is the basis of the drawing data. The depth d of the striped groove 26 caused by maskless exposure is reduced by irradiating twice as much light as _OFF . In the method shown in FIG. 4, only the leaked light with the intensity IL _OFF is irradiated to the non-photosensitive portion of the overlapping region. When attention is paid to the first operation of one time, the exposure is performed. The intensity of the irradiated light changes discontinuously at the boundary between the region where the region ER passes only once and the overlapping region.

However, the method for reducing the depth d of the striped groove 26 caused by maskless exposure is not limited to such a method, and may be another method. That is, the intensity IR n _{+ 1} of light to be irradiated when the exposure intensity of light IR _n that irradiation when exposing a strip-shaped region Q _n on the left, the right band region Q _{n + 1,} and the photosensitive insulating film 23 the relationship between the total IR _T of the intensity of light emitted, for example, a thick line P4 shown in FIG. 5 ', P5', may be the relationship as P6 '.

In the exposure method shown in FIG. 5, light of intensity IL _AO (= 2 · IL _OFF ) is irradiated to the outside of the overlapping area, and the intensity from intensity IL _AO increases toward the outside of the exposure area ER. Irradiate light that gradually decreases to IL _OFF .

Also in this case, of the overlap region, the total amount IR _T of the intensity of light irradiated to the area that is specified so as not to irradiate light in the layout data, as a thick line P6 ', substantially uniform values (IL _AO ). Therefore, it is considered that the depth d of the groove 26 generated on the surface of the photosensitive insulating film 23 remaining after the development is reduced to such an extent that the appearance quality and display quality of the liquid crystal display panel (liquid crystal display device) are not deteriorated.

  Accordingly, the inventors of the present application perform drawing data that satisfies the conditions shown in FIG. 5 in the step of forming the second insulating layer 12 and the third insulating layer 14 in the step of forming the TFT substrate 1. Was used to measure the depth d of the groove 26 formed on the surface, and the average value was 4 nm. Moreover, when the liquid crystal display panel using said TFT substrate 1 was produced and the external appearance was test | inspected, the visual determination level ULV of the striped nonuniformity resulting from maskless exposure was 5 (acceptable level).

  That is, when the exposure method as shown in FIG. 5 is used, the effect of reducing the stripe unevenness of the liquid crystal display panel (liquid crystal display device) due to the maskless exposure is higher than the exposure method shown in FIG. It is done.

FIG. 6A and FIG. 6B are schematic diagrams for explaining an example of another operational effect in the modification of the first embodiment.
FIG. 6A is a schematic graph showing an example of a phenomenon that can occur in the exposure method shown in FIG. FIG. 6B is a schematic graph showing an example of a phenomenon that can occur in the exposure method shown in FIG.

  In the exposure method of the first embodiment, as described above, the first operation in which exposure is performed while moving the exposure region ER in the first direction (v-axis direction), and the first operation in which the exposure region ER is orthogonal to the first direction. In this exposure method, the second operation of moving in the direction 2 (u-axis direction) is repeated. At this time, the first operation and the second operation are performed, for example, by moving the stage on which the insulating substrate 6 (mother glass) is mounted by numerical control.

At this time, for example, as shown in FIG. 4, the second operation exposes the coordinates U3 of the end of the exposure region ER when exposing the left strip region Q _n and the right strip region Q _{n + 1} . The distance between the exposure area ER and the coordinate U2 at the end of the exposure is set to a predetermined value (W _CO1 ).

However, when the second operation is performed, for example, as shown in FIG. 6A, the end of the exposure region ER when the right band region Q _{n + 1} is exposed is shifted to the coordinate U2 ′, and the coordinate U3 May be smaller than the predetermined value by ΔW.

In this case, the distribution of the total amount IR _T of the intensity of light irradiated is as shown in thick line P6 shown in FIG. 6 (a), the boundary BL _Q of adjacent band-like region, the total amount of the intensity of the light emitted There is a section in which becomes half. In this case, when the photosensitive insulating film 23 is developed, for example, double line-shaped steps are arranged in stripes with the width W _Q of the band-like region Q on the surface of the insulating film remaining after the development.

On the other hand, when the second operation is performed in the exposure method according to the modification, for example, as shown in FIG. 6B, the end of the exposure region ER when the right belt-shaped region Q _{n + 1} is exposed has coordinates U2 When the distance to the coordinate U3 is smaller than the predetermined value by ΔW, the total amount of intensity of the irradiated light is as indicated by a thick line P6 ′. That is, in the overlap region, there is a section in which the total amount of light irradiated by the shift ΔW decreases, but the amount of decrease is smaller than that shown in FIG. Therefore, compared with the case shown in FIG. 6A, the effect of preventing the deterioration of the appearance quality and display quality of the liquid crystal display panel (liquid crystal display device) due to the level difference generated on the surface of the photosensitive insulating film 23 remaining after development is high. it is conceivable that.

FIG. 7A to FIG. 7C are schematic views showing another example of the method for exposing the border of the band-like region in the conventional maskless exposure.
FIG. 7A is a schematic plan view showing another example of the exposure method of the border of the band-like region in the conventional maskless exposure. FIG. 7B is a schematic diagram showing an example of the amount of light when the position of the DD ′ line in FIG. 7A is not exposed. FIG. 7C is a schematic diagram showing an example of the amount of light when the position of the DD ′ line in FIG.

  In the first embodiment, a method as shown in FIGS. 2D to 2F is given as an exposure method for the border of the band-like region in the maskless exposure. That is, the exposure method of the first embodiment is an exposure method in which all the light amount control elements 25a included in the light modulation component 25 are involved in exposure of the exposure region ER.

  However, among the light modulation components 25 used for maskless exposure, a light amount control element used only when, for example, inspecting or adjusting the light amount, outside the light amount control element 25a involved in exposure of the exposure region ER. Some (hereinafter referred to as dummy elements) are arranged.

  When the photosensitive insulating film 23 is exposed using the light modulation component 25 having such a dummy element, the dummy element is always set to a state in which no light is irradiated.

  However, since the dummy element has the same configuration as the light quantity control element 25a involved in exposure, even if the dummy element is not irradiated with light, the above-described leakage light is exposed to the photosensitive insulating film 23 through the dummy element. Is irradiated.

Therefore, when exposing the photosensitive insulating film 23 by using the optical modulation component 25 having a dummy element, for example, as shown in FIG. 7 (a), both ends of the exposure region ER, the width W _D, always There is an area ER ′ where the leaked light is irradiated.

Accordingly, Figure 7 when not sensitive to the position of the line D-D 'shown in (a), the intensity IR _n of the light irradiated when exposing a strip-shaped region Q _n of the left, right band-like region Q _{n + 1} the relationship between the total IR _T of the intensity of light applied to the light intensity IR n _{+ 1,} and the photosensitive insulating film 23 is irradiated at the time of exposure, for example, a thick line P7 shown in FIG. 7 (b), P8 , P9. That is, the width W _CO2 (= W _CO1 + 2 · W _D ) of the region where the leaked light of intensity IL _OFF is irradiated twice is wider than the case shown in FIG. 26 becomes wider.

Further, when exposing the position of the DD ′ line shown in FIG. 7A, the intensity IR _{n of} light irradiated when exposing the left belt-like region Q _n and the right belt-like region Q _{n + 1.} the intensity of the light irradiated when exposing the IR n _{+ 1,} and the relationship between the total IR _T of the intensity of light applied to the photosensitive insulating film 23, for example, a thick line P7 shown in FIG. 7 (c) ', The relationship is P8 ', P9'. In the case to expose the position of the line D-D 'shown in FIG. 7 (a), as described above, the relative value of the total amount IR _T of the intensity of light irradiated to the overlapping area is 1 or more There is no problem.

  In the second embodiment, a method for suppressing the generation of the striped grooves 26 resulting from the maskless exposure in the maskless exposure using the light modulation component 25 will be briefly described.

  FIG. 8 is a schematic diagram for explaining the photosensitive material film exposure method of Example 2 according to the present invention.

In the exposure method of the photosensitive insulating film 23 of Example 2, the light irradiated when exposing the left band-like region Q _n when the position of the DD ′ line shown in FIG. intensity IR _n, the relation of the right band region Q _{n +} intensity of the irradiation light _{when 1} exposing the IR n _{+ 1,} and the photosensitive total IR _T of the intensity of the light irradiated to the insulating film 23, for example, The relationship is as indicated by the thick lines P10, P11, and P12 shown in FIG.

That is, in the exposure method in Example 2, first, the two adjacent band-like region Q _n, the light quantity control element responsible for the exposure of the overlapping area in the Q n _{+ 1} boundary BL _Q (section from coordinate U5 to the coordinates U6) 25a is not irradiated with light, and only leakage light with intensity IL _OFF is irradiated.

At this time, in the exposure of the left belt-like region Q _n , the section from the coordinate U3 to the coordinate U6 is the region ER ′ where the leakage light is always irradiated. Therefore, in the exposure of the band-like region Q _n on the left side, the light quantity control element 25a responsible for the exposure in the section from the coordinates U5 to the coordinates U3 is set so as not to irradiate light, and only the leaked light having the intensity IL _OFF is irradiated. To do.

Further, in the exposure of the right band region Q _{n + 1} , the section from the coordinate U5 to the coordinate U2 is the region ER ′ where the leakage light is always irradiated. Therefore, in the exposure of the right belt-like region Q _{n + 1} , the light quantity control element 25a responsible for the exposure in the section from the coordinates U2 to the coordinates U6 is not irradiated with light, and only leaked light with intensity IL _OFF is irradiated. Like that.

In addition, the region outside the overlapping region including the region ER ′ to which the leakage light is always irradiated is irradiated with light having an intensity IL _AO corresponding to twice the leakage light intensity IL _OFF .

In this way, the total IR _T of the intensity of light irradiated to the overlap region and the outer region thereof, a constant value IL _AO. For this reason, the intensity of light applied to other regions other than the regions where the contact holes 22a and 22b are formed is substantially constant, and the amount (depth) of light exposure is also substantially constant. Therefore, it is considered that the striped grooves 26 due to maskless exposure do not occur on the surfaces of the second insulating layer 12 and the third insulating layer 14 obtained after development.

  However, even when the control as shown in FIG. 8 is performed, the striped grooves 26 due to the maskless exposure often occur due to the reasons described in the first embodiment.

  Therefore, the inventors of the present application perform drawing data that satisfies the conditions as shown in FIG. 8 in the step of forming the second insulating layer 12 and the third insulating layer 14 in the step of forming the TFT substrate 1. Was used to measure the depth d of the groove 26 formed on the surface, and the average value was 8 nm. Moreover, when the liquid crystal display panel using said TFT substrate 1 was produced and the external appearance was test | inspected, the visual determination level ULV of the striped nonuniformity resulting from maskless exposure was 4 (pass level).

  That is, even in the exposure method of Example 2, striped grooves 26 resulting from maskless exposure may occur on the surfaces of the second insulating layer 12 and the third insulating layer 14. However, in the liquid crystal display panel (liquid crystal display device) having the second insulating layer 12 and the third insulating layer 14 formed by applying the exposure method of Example 2, striped unevenness due to the striped grooves 26 is achieved. Will not be observable. Therefore, in the liquid crystal display panel (liquid crystal display device) formed by applying the exposure method of Example 2, it is possible to prevent the appearance quality and display quality from being deteriorated due to the striped grooves 26.

  As described above, the liquid crystal display panel (liquid crystal display device) formed by applying the exposure method according to the second embodiment can prevent deterioration in appearance quality and display quality due to maskless exposure.

In the second embodiment, the intensity IL _AO of the light radiated to the outside of the overlapping area is mechanically made twice the intensity IL _OFF of the leakage light radiated to the overlapping area. However, the intensity IL _AO of the light radiated to the outside of the overlapping area is not limited to this. For example, the total amount of leakage light radiated to the overlapping area is measured more accurately, and the intensity becomes equal to the total amount. Of course, it may be set to. Furthermore, the intensity IL _AO of the light radiated to the outside of the overlapping region is measured, for example, by measuring the amount of decrease in the thickness of the overlapping region when developed, and the amount of decrease in the thickness outside the overlapping region is measured in the overlapping region. Of course, the strength may be set equal to the amount of decrease.

FIG. 9A and FIG. 9B are schematic diagrams for explaining a modification of the exposure method of the second embodiment.
FIG. 9A is a schematic diagram for explaining a first modification of the exposure method of the second embodiment. FIG. 9B is a schematic diagram for explaining a second modification of the exposure method of the second embodiment.

As an example of the exposure method of the second embodiment, the method shown in FIG. 8 is the intensity IL of the leaked light that is applied to the overlapping area over the entire area designated not to be exposed in the layout data that is the basis of the drawing data. The depth d of the striped groove 26 caused by maskless exposure is reduced by irradiating twice as much light as _OFF .

However, as described in the first embodiment, the method for reducing the depth d of the striped groove 26 caused by the maskless exposure is not limited to this method, and may be another method. Of course. That is, examples of light intensity IR _n that irradiation when exposing a strip-shaped region Q _n of the left side of the exposure method 2, the intensity IR n _{+ 1} of light to be irradiated when exposing the right band region Q _{n + 1} , and the relationship of the total amount IR _T of the intensity of light applied to the photosensitive insulating film 23, for example, a thick line P10 shown in FIG. 9 (a) ', P11' , may be related, such as P12 '.

In the exposure method shown in FIG. 9A, light of intensity IL _AO1 (= 3 · IL _OFF ) is irradiated to the outside of the overlapping region (including the region ER ′ to which constantly leaking light is irradiated), and the overlapping region _Are irradiated with light having such an intensity that the total amount of light irradiated by the two exposures is IL _AO1 (= 3 · IL _OFF ).

At this time, in the exposure of the left belt-like region Q _n , the section from the coordinate U3 to the coordinate U6 is the region ER ′ where the leakage light is always irradiated. Further, the section from the coordinates U5 to the coordinates U2 is an area to which leakage light is irradiated when the right belt-like area Q _{n + 1} is exposed. Therefore, in the exposure of the left belt-like region Q _n , the light amount control element 25a responsible for the exposure in the section from the coordinates U5 to the coordinates U2 is controlled to be irradiated with the light amount IL _AO2 (= 2 · IL _OFF ). Further, the light amount control element 25a responsible for the exposure in the section from the coordinates U2 to the coordinates U3 gradually decreases from the intensity IL _AO2 (= 2 · IL _OFF ) to the intensity IL _OFF as it goes outside the exposure region ER. Control to such a state.

On the other hand, in the exposure of the belt-like region Q _{n + 1} on the right side, the section from the coordinate U5 to the coordinate U2 is the region ER ′ where the leak light is always irradiated. Further, the section from the coordinates U3 to the coordinates U6 is a region where the leakage light is irradiated when exposing a strip-shaped region Q _n of the left side. Therefore, in the exposure of the right belt-like region Q _{n + 1} , the light quantity control element 25a responsible for the exposure in the section from the coordinates U3 to the coordinates U6 is controlled to be irradiated with the light quantity IL _AO2 (= 2 · IL _OFF ). . Further, the light amount control element 25a responsible for the exposure in the section from the coordinates U2 to the coordinates U3 gradually decreases from the intensity IL _AO2 (= 2 · IL _OFF ) to the intensity IL _OFF as it goes outside the exposure region ER. Control to such a state.

In this way, the total IR _T of the intensity of light to be irradiated, such as the thick line P12 ', it becomes uniform value (IL _AO1). Therefore, it is considered that the depth d of the groove 26 generated on the surface of the photosensitive insulating film 23 remaining after the development is reduced to such an extent that the appearance quality and display quality of the liquid crystal display panel (liquid crystal display device) are not deteriorated.

  Therefore, in the process of forming the second insulating layer 12 and the third insulating layer 14 among the processes of forming the TFT substrate 1, the inventors of the present application satisfy the conditions as shown in FIG. Maskless exposure was performed using the drawing data to be satisfied, and the depth d of the groove 26 formed on the surface was measured. The average value was 4 nm. Moreover, when the liquid crystal display panel using said TFT substrate 1 was produced and the external appearance was test | inspected, the visual determination level ULV of the striped nonuniformity resulting from maskless exposure was 5 (acceptable level).

  That is, the exposure method as shown in FIG. 9A has the effect of reducing the uneven stripes of the liquid crystal display panel (liquid crystal display device) due to maskless exposure, compared to the exposure method shown in FIG. It is considered high.

  By the way, in the exposure method shown in FIG. 9A, the region designated not to be exposed in the layout data is irradiated with light that is about three times the amount of leakage light. Therefore, the amount of decrease in the insulating film when developed is increased. For this reason, it is necessary to increase the film thickness when forming the photosensitive insulating film in consideration of the amount of decrease, which causes an increase in material cost, for example.

Therefore, in the case where the amount of light with respect to the overlapping region is changed stepwise, the intensity IR _{n of} light emitted when exposing the left belt region Q _n and the light irradiated when exposing the right belt region Q _{n + 1.} intensity IR _{n + 1,} and the relationship between the total IR _T of the intensity of the light-sensitive light irradiated to the insulating film 23, for example, a thick line P10 shown in FIG. 9 (b) ', P11' , such as P12 ' It may be related.

As shown in FIG. 9 (b), the exposure region ER only IL the amount of area through once _{AO (= 2 · IL OFF)} , the exposure region ER, 'IL the amount of area that passes only once _AO' ER ( = 1.5 · IL _OFF ),
To, if reducing the amount of the overlap region from the IL _AO 'IL _OFF stepwise, the total IR _T of the intensity of light applied to the photosensitive insulating film 23 becomes _{IL AO (= 2 · IL OFF} ) . In other words, equal to the total IR _T of the intensity of light applied to the photosensitive insulating film 23 in the exposure method shown in FIG. For this reason, in FIG. 9B, the exposure method shown in FIG. 9A is more effective than the exposure method shown in FIG. It can be said that the exposure method shown is more desirable.

  The present invention has been specifically described above based on the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. is there.

  For example, in Example 1 and Example 2, the method of forming the second insulating layer 12 and the third insulating layer 14 in the liquid crystal display panel having the pixel having the configuration shown in FIGS. 1A and 1B. Was given as an example. However, the exposure method of the present invention is not limited to this, and can naturally be applied to a method for forming an insulating layer of a liquid crystal display panel (TFT substrate 1) having pixels of other configurations.

  In Example 1 and Example 2, when the photosensitive insulating film is exposed, the photosensitive insulating film is divided into a plurality of strip-like regions Q and is exposed only during the first operation. . However, the method of moving the exposure region ER in the exposure method of the present invention may be any method that scans the entire photosensitive insulating film, and is not limited to the method described in this specification, and can be changed as appropriate. It is. Accordingly, the plurality of grooves 26 formed on the surfaces of the second insulating layer 12 and the third insulating layer 14 are not limited to stripes, but may be annular (concentric) or spiral. is there.

  Further, the exposure method of the present invention is not limited to the method for forming the insulating layer of the liquid crystal display panel (TFT substrate 1), but for example, the method for forming the insulating layer of a self-luminous display panel using an organic EL material. Of course, it can be applied.

  Furthermore, as a modification of the exposure method of the second embodiment, the exposure method as shown in FIGS. 9A and 9B can be applied to the exposure method of the first embodiment.

  FIG. 10 is a schematic diagram for explaining another modification of the exposure method of the first embodiment. FIG. 11 is a schematic diagram for explaining still another modification of the exposure method of the first embodiment.

In the exposure method shown in FIG. 5 as a modification of the exposure method of the first embodiment, the intensity of the light irradiated to the overlapping region is changed from the intensity IL _{AO of} the light irradiated to the outer side to the intensity IL _{OFF of the} leaked light. It is decreasing gradually. However, when the intensity of light irradiated to the overlapping area is changed stepwise, the intensity IR _{n of} light irradiated when exposing the left band area Q _n and the right band area Q _{n + 1} are exposed. the relationship between the total IR _T of the intensity of the light irradiated to the light intensity IR n _{+ 1,} and the photosensitive insulating film 23 to be irradiated when, for example, a thick line P4 shown in FIG. 10 ', P5', P6 'of Of course, such a relationship may be used. That is, for example, the intensity of irradiated light may be changed discontinuously at the boundary portion between the region where the exposure region ER passes only once and the overlapping region. Even in such a case, in the overlapping region and the region outside thereof, if the total amount IR _T of the intensity of light applied to the photosensitive insulating film 23 by exposure at constant becomes such a condition (quantity of light), the insulation after development It is possible to prevent a striped step from occurring on the surface of the film.

Further, in the exposure method shown in FIG. 10, the total IR _T of the intensity of light applied to the photosensitive insulating film 23 is _{IL AO1 (= 3 · IL OFF} ). Therefore, when the amount of light is changed discontinuously at the boundary between the overlapping region and the outer region, the intensity IR _{n of} the light irradiated when the left belt region Q _n is exposed, the right belt region Q _{n +} intensity IR n _{+ 1} of light to be irradiated when exposing the _1, and the relationship between the total IR _T of the intensity of light applied to the photosensitive insulating film 23, for example, a thick line P4 shown in FIG. 11 ', P5' , P6 ′ is preferable.

DESCRIPTION OF SYMBOLS 1 TFT substrate 2 Opposite substrate 3 Liquid crystal layer 4 1st polarizing plate 5 2nd polarizing plate 6 1st insulating substrate 7 Scanning signal line 8 1st insulating layer 9 Semiconductor layer (TFT element) 10 Video signal line 11 Source-drain electrode 12 Second insulating layer 13 Common electrode 14 Third insulating layer 15 Pixel electrode 16 First alignment film 17 Second insulating substrate 18 Black matrix 19 Color filter 20 Flattening layer 21 Second alignment film 22a, 22b Contact hole 23 Photosensitive insulating film 24 Substrate 25 Light modulation component 25a Light quantity control element 26 Groove

Claims (8)

A display panel having a display area composed of a plurality of pixels;
The display panel has a plurality of insulating layers,
One or more insulating layers of the plurality of insulating layers have through holes, and a plurality of grooves are striped at an interval larger than the pixel size at the interface with the other insulating layers. A display device in a line,
The display device, wherein the groove of the insulating layer has a depth of 10 nm or less.   The display device according to claim 1, wherein the groove of the insulating layer has a depth of 5 nm or less.   The display device according to claim 1, wherein the display panel is a liquid crystal display panel. In the manufacturing process of a display panel having a display area composed of a plurality of pixels,
A step of forming an insulating layer formed by exposing and developing a photosensitive insulating film;
The photosensitive insulating film is exposed in a first operation for moving a region that can be exposed at a time in a first direction, and in a second direction that is orthogonal to the first direction. A method of manufacturing a display device that repeats the second operation to be moved and overlaps a region that can be exposed at a time by a predetermined width,
In the exposure of the photosensitive material film, the intensity of the leakage light applied to the overlapping area is compared with the area outside the overlapping area where the area that can be exposed at least twice passes through the area that is not exposed to light. A method for manufacturing a display device, characterized by irradiating light having the same intensity as the total amount. In the manufacturing process of a display panel having a display area composed of a plurality of pixels,
A step of forming an insulating layer formed by exposing and developing a photosensitive insulating film;
The photosensitive insulating film is exposed in a first operation for moving a region that can be exposed at a time in a first direction, and in a second direction that is orthogonal to the first direction. A method of manufacturing a display device that repeats the second operation to be moved and overlaps a region that can be exposed at a time by a predetermined width,
In the exposure of the photosensitive material film, the region not exposed to light is irradiated with light having a sufficiently small intensity as compared with the intensity of light irradiated to the region to be exposed, and once in the region not exposed to light. The total amount of the intensity of light applied to the overlapping area where the area that can be exposed to at least twice passes is equal to the intensity of the light applied to the area outside the overlapping area. Device manufacturing method.   6. The method of manufacturing a display device according to claim 4, wherein the region that can be exposed at a time has a region that is always irradiated with only the leakage light on an outer peripheral portion thereof. The exposure of the photosensitive material film is performed during the first operation,
6. The method of manufacturing a display device according to claim 4, wherein the region that can be exposed at one time has a dimension in the second direction larger than a dimension of the pixel.   The exposure of the photosensitive material film uses an exposure apparatus having a light modulation element that generates a pattern of light to be irradiated to the photosensitive material film by numerical control based on drawing data created based on layout data prepared in advance. The method for manufacturing a display device according to claim 4, wherein the method is performed.

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