JPH06202314A - Printing plate, its production and pattern forming method using the plate - Google Patents

Abstract

PURPOSE:To produce a printing plate having a fine pattern and uniform depth, capable of preventing the misregistration in printing even if a body to be printed is contracted by heat treatment, capable of filling the recess of the plate with an ink, which is irradiated with OV from the glass substrate side and cured, and capable of precisely printing while preventing the sagging of the ink. CONSTITUTION:A transparent conductive layer 2 is formed on a glass substrate 1, and an unplated pattern 3 is formed thereon by photolithography. When a protrusion consisting of a metalic layer is formed on the part except the unplated pattern 3, the same metal as an electroless plating material is firstly deposited by electroplating to form an electroplating layer 5 having a thickness of <=30% of the height of the protrusion, and an electroless plating layer 7 having a thickness of >=70% of the height of the protrusion is formed by electroless plating. A material having the same linear expansion coefficient and flexibility when the substrate 1 is heat-treated as those of a substrate to be printed is used for the substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in the manufacture of electronic components such as thin film transistor circuits, and more specifically, a printing plate and a pattern for forming a fine pattern by printing on an object to be printed such as a thin film transistor circuit substrate. It relates to a forming method.

[0002]

2. Description of the Related Art Recently, sizes of 30 to 1 have been formed on a glass substrate.
When forming a fine pattern of 00 μm, a pattern forming method using a printing technique is widely used.
For example, formation of a resist pattern at the time of manufacturing a thin film transistor circuit and pattern formation of a color filter used for a liquid crystal television are performed by printing. For the formation of such a fine pattern, a method called a photolithography method has been used exclusively before. However, recently, the printing method has begun to be used in order to reduce the production cost and increase the area.

The characteristics of the specifications required for these printings are as follows:
The ink thickness is thicker than normal printing, and the ink thickness needs to be controlled. Generally, the thickness of the printed ink depends on the thickness of the ink applied to the printing plate used. Therefore, it is desirable that the printing plate has a large amount of ink and that the amount can be controlled by changing the plate depth. Actually, an intaglio or plano intaglio devised in the manufacturing method is preferably used. Has been. The intaglio plate is a plate in which ink is filled in the recesses, and the plano intaglio plate is a type of intaglio plate in which the surface of the recesses is ink-philic and the surface of the projections is ink-repellent. The essential points of the device are that the plate depth can be made constant regardless of the size of the pattern, that the plate depth can be easily controlled, and that the plate depth can be made constant over the entire surface of the printing plate. Here, the plate depth means the depth of the concave portion of the plate. In practice, an etching method is used as a method for producing a printing plate.
No. 3306 proposes a method in which an etching stop layer is provided so that the plate depth becomes constant regardless of the etching width.

However, recently, even in a fine portion of a thin film transistor circuit, it is required to form a resist pattern on a glass substrate by a printing method in order to reduce the cost and to cope with a large area. For example, it is required to perform printing with a line width of 5 to 30 μm and a positional accuracy of ± 1 to several μm on a substrate having a diagonal size of 20 inches to 40 inches. The reason is that if the line width is made thin, not only becomes compact, but also the circuit characteristics are improved. Further, in the thin film transistor circuit of the pixel portion on the active matrix type liquid crystal display panel, there is a great advantage that the aperture ratio is improved when the line width is reduced. Further, it becomes possible to incorporate the peripheral drive circuit on the same substrate. Therefore, it is necessary to print a finer pattern without defects.

It is difficult to form an intaglio or plano intaglio suitable for such a purpose by an etching method because side etching occurs along with the etching. In general, it is known that etching causes side etching having an etching depth, that is, about twice the plate depth. Since the plate depth is generally required to be 1 to 10 μm, it is difficult to accurately form a pattern having a line width of several to 30 μm. Therefore, in practice, various measures such as making the dimensions of the pattern of the original plate thinner in advance by the side etching are necessary. However, in the case of a pattern in which various line widths are mixed, there is a limit to the countermeasure. Also,
When the printing plate has a large area, it is more difficult to uniformly etch it.

Another method of forming the printing plate depth is electroplating. That is, this is a method in which a pattern is formed on the plate substrate with a photoresist that is not to be plated, and then projections are formed by electroplating to obtain the plate depth. According to this method, the resolution of the obtained plate is as high as that of the photoresist, and a pattern of about 1 μm can be obtained. This method also has the advantage that the manufacturing process is very simple.

[0007]

However, the above electroplating method has a problem that it is difficult to obtain a uniform plating film thickness, that is, a plate depth in a large area. The unevenness of the plate depth is preferably within ± 5% over the entire surface. The plate depth unevenness not only leads to ink thickness unevenness, but also causes line width unevenness and, in some cases, resolution unevenness. In electroplating, the thickness of the plating film obtained is approximately proportional to the current density of that portion integrated by the energizing time, but in the pattern in which large and small patterns are distributed at various densities, the size of the pattern, The current density differs in parts due to factors such as the degree of sparseness and denseness, and it is very difficult to make this integrated value constant over the entire surface, which causes unevenness in plate depth. On the other hand, in order to make the value obtained by integrating the current density with the energization time as uniform as possible, there is also a method of using a method such as the arrangement of the shield plate, the dummy pattern, and the anode. This is effective when the power pattern is a set of patterns of almost the same size and is distributed almost uniformly on the substrate, but it is not applicable when it is not.

Further, when a printing method is used for forming a pattern in the field of manufacturing a thin film transistor circuit, accuracy of printing position is also required. That is, in the formation of the thin film transistor circuit, the constituent layers of the thin film transistor are formed on the glass substrate several times during the manufacturing process, and the glass substrate is heated and shrinks each time. At this time, the pattern already formed on the glass substrate also contracts. On the other hand, printing is performed after each constituent layer of the thin film transistor is formed, and the size of the pattern is required to match the size of the previously printed pattern within several μm. As a measure against this point, a printing plate is used in which the pattern size is shrunk by an amount commensurate with the shrinkage of the glass substrate, but for that purpose the design size data is completely changed to create the original plate. Must be
It was a problem.

Another problem in the prior art is that ink drips around the printed ink pattern. In other words, the part where the ink is dripping becomes a part with low light blocking property and etching liquid resistance,
It has not been possible to meet the recent demand for printing fine patterns without defects. For example, normally, it is necessary to keep the line width variation within ± 5% of the line width, but if the required ink thickness is 2 μm, and the sag width is about 2 μm, this sag Since the width does not depend on the width of the pattern, it is ± 4% for a line width of 50 μm (sag occurs on both sides) and ± 10% for a line width of 20 μm.
Becomes If the viscosity of the ink is increased to reduce sagging, bubbles in the ink will not escape and pinholes will increase, which cannot be used when forming a resist pattern for forming a thin film transistor circuit. It was

As a means for solving the problem of ink dripping, there is a method of curing the ink on the printing plate. For example,
Japanese Patent Application Nos. 2-81624 and 3-32451 propose methods of irradiating UV light to cure the ink on the printing plate. However, depending on the type of ink used, only the surface of the ink hardens, and it may be difficult to achieve the purpose.

The present invention has been made in view of the above problems, and a printing method is provided in which the plate depth is formed uniformly irrespective of the shape and position of the pattern, and the problems such as misregistration and ink dripping during printing are eliminated. It is an object of the present invention to provide a printing plate capable of forming a finer pattern with higher accuracy, a manufacturing method thereof, and a pattern forming method.

[0012]

In order to solve the above-mentioned problems, the printing plate according to claim 1 of the present invention is an intaglio plate or a plano-concave plate, and the substrate of the printing plate comprises a glass substrate, and the glass substrate. A convex portion made of a metal layer is formed on the top. The printing plate according to claim 2 is the printing plate according to claim 1 in which a conductive layer is formed on a glass substrate. The printing plate according to claim 3 is the printing plate according to claim 1 or 2, wherein the linear expansion coefficient of the glass substrate and the expansion and contraction behavior when the glass substrate is heat-treated are This is the same as the expansion and contraction behavior when the substrate is heat-treated. A printing plate according to a fourth aspect is the printing plate according to the second aspect, wherein the conductive layer is a transparent conductive layer.

The method for producing a printing plate according to claim 5 of the present invention is the method for producing an intaglio or plano-concave plate using a plating method as a method for forming a convex portion, wherein a glass substrate is used as a substrate of the printing plate, and the glass is used. A non-plating pattern is formed on a substrate by a photolithography method, and a convex portion made of a metal layer is formed on a portion other than the non-plating pattern by a plating method, and then the non-plating pattern is removed. The method for manufacturing a printing plate according to claim 6, wherein in the method according to claim 5, when forming the convex portion made of a metal layer, 70% or more of the height of the convex portion is formed by electroless plating. To do. The method for manufacturing a printing plate according to claim 7, wherein in the manufacturing method according to claim 6, after forming a conductive layer on the glass substrate, a non-plating pattern is formed on the conductive layer by photolithography. When forming a convex portion made of a metal layer on a portion other than this non-plating pattern, first, the same metal as the metal to be electroless plated is deposited by electroplating to form 30% or less of the height of the convex portion. Then, 70% or more of the height of the convex portion is formed by an electroless plating method.

According to the eighth aspect of the present invention, there is provided a method for forming a pattern, wherein the printing plate according to the second aspect is used to form a pattern on an object to be printed while the conductive layer is grounded. According to a ninth aspect of the present invention, there is provided a method of forming a pattern, wherein the printing plate of the second aspect is used to form a pattern on an object to be printed in a state where the conductive layer and the object to be printed are electrically connected. The pattern forming method according to claim 10 uses the printing plate according to claim 4 above, and after filling the concave portion of the printing plate with UV curable ink, irradiating UV light from the glass substrate side of the printing plate. The ink is cured and then the ink is transferred to the printing medium. In the present invention, the plating method includes the electroplating method and the electroless plating method.

[0015]

According to the present invention, the minimum line width is 3 μm by using the glass material as the substrate and forming the protrusions by the plating method.
A printing plate having a minute pattern can be obtained. As a method for forming the convex portion of the printing plate, if the required uniformity cannot be obtained by the electroplating method, use the electroless plating method instead of the electroplating method in the main step of forming the plate depth. Thereby, a metal layer having a uniform thickness can be obtained. As a pretreatment method for performing electroless plating on a glass substrate, a metal layer is previously formed on the glass substrate by an appropriate means such as a vacuum film forming method and electroless plating is performed, or a conductive film is first formed. After forming, it is desirable to form a metal film thereon by electroplating and then perform electroless plating. On the other hand, when the pretreatment method of the usual electroless plating is used, the plating start time is slower in the part with a narrow line width than in the part with a wide line width, so that the plating thickness is uneven. Occurs. It is also recognized that the start of electroless plating becomes unstable and there are many defects. It is considered that this is because the step of forming the non-plating pattern by the photolithography method is performed after the pretreatment of the electroless plating, and thus the delicate conditions for starting the electroless plating are affected. Therefore,
These problems can be solved by forming a metal layer that serves as a catalyst layer for electroless plating prior to electroless plating, and uneven plate depth can be achieved regardless of the size of the substrate or the position or shape of the pattern. , Can be suppressed within ± 5% on the entire surface.

When a metal layer is formed by electroplating prior to electroless plating, the thickness of the metal layer is 30% or less of the plate depth formed by the projections of the printing plate. The reason for this is that if the allowable range of plate depth unevenness in the printing plate is ± 5% and the plating thickness unevenness in electroless plating is a maximum of ± 2.5%, the thickness unevenness allowed for electroplating is When the thickness of the electroplating layer is 30% of the total thickness, it becomes about ± 10%. If the unevenness of the plating thickness due to electroplating is less than this, the effect of using the electroless plating method is reduced. Is. In order to enable electroplating, a conductive layer is formed on the glass substrate as an electroconductive layer during electroplating.

In the printing plate of the present invention, the coefficient of linear expansion of the glass substrate used as the substrate of the printing plate and the expansion and contraction behavior when heat-treated, the coefficient of linear expansion of the substrate to be printed, and the expansion and contraction behavior when heat-treated. By making the values equal to each other, it is possible to easily deal with the contraction of the printing medium. For example, in the case where the substrate to be printed is heated and contracts many times like the thin film transistor circuit, and the pattern formed thereon also contracts at the same time, the printing plate is also subjected to heat treatment under the same conditions. The substrate of the printing plate is also shrunk in the same manner so that the displacement of the thin film transistor circuit pattern due to the difference in shrinkage between the circuit glass substrate and the printing plate is 2 μm.
It can be suppressed to m or less. As described above, since it is not necessary to form the pattern of the printing plate in a size reduced from the original plate in order to prevent the displacement, the economical effect is large. In addition, since the printing plate can easily cope with the shrinkage of the circuit board, the preheat treatment of the substrate for the thin film transistor circuit, which requires a considerably long time at present, often occurs in a short time. Further, in some cases, there is an advantage that the preliminary heat treatment becomes unnecessary.

Further, when a UV curable ink is used for printing, it is preferable that the conductive layer on the glass substrate is a transparent conductive layer. As a result, the ink can be cured by irradiating UV light from the back surface of the printing plate, that is, from the glass substrate side, and ink dripping can be prevented.

Further, it has been recently revealed that when a glass plate is used as a substrate of a printing plate, a problem of static electricity generation occurs. However, a conductive layer is provided on the entire surface of a necessary portion of the substrate for grounding. Alternatively, this problem can be solved by electrically connecting the conductive layer and the printing medium. That is, since the glass substrate has low electric conductivity, when used as a printing plate, static electricity may be generated between the thin film transistor and the thin film transistor circuit substrate, which is an ink transfer partner, depending on printing conditions, and the thin film transistor may be destroyed. It was In addition, this phenomenon may or may not easily occur depending on the type of pattern. It was less likely to occur in the case of a pattern in which the metal portions were continuous, and was likely to occur in the case of a printing plate without any metal, or in the case of a printing plate in which metal patterns were isolated. As a countermeasure, it could be prevented by raising the humidity in the room. However, it is a problem that it may occur at normal humidity in a clean room. Therefore, according to the present invention, it is possible to prevent damage to the thin film transistor due to generation of static electricity in normal humidity of a clean room, and thus there is an advantage that the clean room can be easily managed.

The present invention will be described in detail below. FIG. 1 is a sectional view showing an example of manufacturing a printing plate of the present invention in the order of steps.
Reference numeral 1 in the figure is a glass substrate. The printing plate of the present invention uses the glass substrate 1 as a base. Further, as the glass material, one having the same anti-heat treatment behavior as that of the material to be printed is preferably used. A glass material having the same anti-heat treatment behavior as that of the material to be printed means that when the material to be printed and the printing plate are heat-treated under the same conditions, the degree of shrinkage is substantially the same and already formed on the material to be printed. It means a glass material in which the difference in size between the pattern and the pattern of the printing plate does not affect the operation of the thin film transistor circuit. For example, thin film transistors for active matrix liquid crystal televisions are often formed on low expansion glass that has been preheated. In that case, the same glass material and the same preheat treatment are used as the substrate of the printing plate. The glass substrate 1 that has been subjected to is used. Preliminary heat treatment of the thin film transistor is performed for the purpose of preliminarily causing shrinkage due to heating at the time of film formation of each layer of the thin film transistor to be performed thereafter to reduce the shrinkage at the time of film formation. It is performed under the condition of cooling to 200 ° C. over time. By using the glass substrate 1 having the same anti-heat treatment behavior as the glass material of the circuit board as the substrate of the printing plate, it is highly possible that the preliminary heat treatment of the thin film transistor as described above can be completed in a short time. In some cases, heat treatment may not be necessary.

On such a glass substrate 1, first, as shown in FIG.
As shown in (b), the conductive layer 2 is formed. In the present invention, the conductive layer 2 is formed for the purpose of being used as an electric conductive layer for electroplating which will be described later, and may be omitted when the electroplating is not performed. The sheet resistance value of the conductive layer 2 may be such that the unevenness of the thickness of the plated film in the electroplating process described later falls within a predetermined range, depends on the size and distribution of the pattern, and is preferably determined by experiment. . Generally, there is no problem if the sheet resistance value is 100Ω / □ or less. The conductive material forming the conductive layer 2 may be a metal such as copper or nickel, or a transparent conductive material such as ITO, zinc oxide or tin oxide. The material of the conductive layer 2 is not particularly limited as long as it does not cause any inconvenience such as dissolution during electroplating in the subsequent step.

Here, by using a transparent conductive material as the conductive layer 2, it is possible to irradiate UV light from the glass substrate 1 side of the printing plate to cure the ink in the printing plate in the printing process. Becomes Even when UV light irradiation is not necessary, for example, when inspecting a printing plate for defects, the pattern can be inspected with transmitted light, or when the dimensions of the pattern match those of the pattern already formed on the printing medium. It is possible to obtain an advantage that it is possible to check whether or not there is any by overlapping them. In addition, in the present invention, the transparent conductive layer 2 refers to a layer having transparency such that these effects can be exhibited.

As the method for forming the conductive layer 2, when a metal layer is formed as this layer, a generally known method can be used. The sputter method, the electron beam evaporation method, the ion plating method, and the electroless plating method can be used. However, due to the difference in the method of forming the conductive layer 2, no difference is observed in the electrolytic plating in the next step. Also,
When forming a transparent conductive layer as the conductive layer 2, many forming methods are known. For example, a sputtering method, a vapor deposition method, or a solution method. In the present invention, since the conductive layer 2 is formed for electroplating, the method is not limited as long as the non-conducting defect portion such as a pinhole is not formed. However, since the plating film grows isotropically, it has a function of covering the pinholes, and there may be no problem even if the conductive layer has minute pinholes which are about a few times smaller than the plating film thickness.

Next, as shown in FIGS. 1 (c) and 1 (d), a photolithography method using a photoresist 3 and a photomask 4 is performed, and as shown in FIG. 1 (e), a conductive film is formed. A resist pattern made of photoresist 3 is formed on the non-plated portion on 2. The photoresist 3 usable here has a resolution sufficient to obtain a predetermined fine pattern, and in the subsequent electroplating step and electroless plating step, the pattern is firmly formed in the electroplating solution and the electroless plating solution. What is maintained is used. Most photoresists used to form semiconductor devices can be used. For example, OMR-85, OF manufactured by Tokyo Ohka
PR-800, Hoechst AZLP-10, etc. can be used. However, since there are acidic and alkaline electroless plating solutions, it is necessary to be careful when selecting the photoresist 3. An alkaline electroless plating solution cannot be used for the photoresist 3 whose stripping solution is strongly alkaline. Further, the thickness of the photoresist 3 is preferably formed to be thicker than the intended plate depth. The reason is that when the plating pattern forming the convex portion for obtaining the plate depth in the printing plate appears above the resist,
This is because it spreads in the same direction during plating, making it difficult to obtain a desired line width. Although the positive photoresist 3 is used in the example of FIG. 1, a negative photoresist can be used as well.

Next, as shown in FIG. 1 (f), a metal catalyst layer 5 to be a catalyst layer for electroless plating by electroplating.
To form. This metal catalyst layer 5 is not necessary in principle when the conductive layer 2 is formed by using a metal having a catalytic action for starting electroless plating such as copper or nickel. However, in practice, electroplating prior to electroless plating results in fewer defects in electroless plating and uniform plating layer thickness. The reason is that, for example, when a copper layer is formed as the conductive layer 2, there is a high possibility that the copper surface is slightly oxidized before electroless plating. It is thought to occur. It is considered that the same applies when another metal is used for the conductive layer 2. In the electroless plating process, making the surface condition of the substrate as uniform as possible at the start of plating is the key to obtaining a uniform plated film.

As the metal deposited by the electroplating method, palladium metal or the same metal as the metal for electroless plating is used. Since metallic palladium has an excellent catalytic action during electroless plating, it can be used universally for electroless plating of various metals. When the metal to be electroless plated is copper, nickel and alloys containing them as a main component, which are commonly used for intaglio or planographic intaglio, copper, nickel and their main components are used even if they are not metallic palladium as a catalyst. It may be an alloy as a component. In this case, as a method of actually performing electroplating, electroplating is performed by applying a voltage to the substrate in a plating bath for performing electroless plating without the need to separately prepare a plating bath or plating solution. It is preferable because plating can be performed.

Next, the substrate 1 on which the metal catalyst layer 5 is formed in this manner is immersed in an electroless plating solution of a target metal under predetermined conditions to form an electroless plating layer 6.
When an electroless plating solution is used as the electroplating solution for forming the metal catalyst layer 5, the voltage application for electroplating is stopped and the solution temperature is maintained at a predetermined temperature to continue electroless plating. be able to. As the metal forming the electroless plating layer 6, in addition to copper and nickel which are generally used for intaglio and plano intaglio, they and their alloys and tungsten, molybdenum and cobalt are used to improve wear resistance. , Carbon, carborundum, alumina, etc. may be co-deposited.

In the case of the planographic intaglio plate, in order to control the adhesion of the ink to the printing plate, it is preferable to use, for example, copper, which is a lipophilic metal, and nickel, which is a hydrophilic metal, separately for two-layer plating. . Nickel is hydrophilic and does not deposit oily ink. Copper, on the other hand, is lipophilic and carries oil-based ink. Further, in consideration of durability, the electroplating layer 7 can be formed on the electroless plating layer 6. For example, if chrome is electroplated, it has a strong abrasion resistance and becomes a portion where ink does not deposit. If zinc is electroplated, it becomes a portion on which the ink is placed. However, when the ink is a water-based type, conversely, copper and zinc are parts where the ink is not placed, and chromium, nickel, ITO, tin oxide, and zinc oxide are parts where the water-based ink is placed.

According to the electroless plating method, the unevenness of the thickness of the plating film can be kept within ± 5% of the plating thickness regardless of the size of the substrate, the shape of the pattern, and the position on the substrate. In addition, even when the electroless plating is performed on the metal catalyst layer 5 formed by electroplating, the thickness unevenness does not depend on the shape or position of the pattern even if the size of the substrate is 400 × 600 mm. Of less than 5%. Further, since there is no factor that the size of the substrate contributes to the thickness of the plated film, it is considered that the thickness unevenness is similarly within 5% even for a larger substrate. The thickness of the metal catalyst layer 5 formed by electroplating may be about 0.1 μm, but since the electroless plating is slow, the thickness of the layer 5 may be reduced to some extent in order to shorten the manufacturing time. May be thicker. In the case of a normal pattern, even if the metal catalyst layer 5 is formed by electroplating up to about 30% of the plate depth, if the electroless plating layer 6 is formed thereafter, unevenness of the plate depth can be suppressed within ± 5%. it can.

After the electroplating and the electroless plating are performed in this way, the photoresist 3 is removed by an appropriate means such as melting to obtain a plating pattern as shown in FIG. 1 (g). The printing plate 11 thus obtained can be suitably used for forming a circuit pattern in which a thin film transistor circuit substrate is used as a printing target.

Prior to forming a circuit pattern using the printing plate of the present invention with a thin film transistor circuit substrate as a printing medium, heat treatment is first performed to shrink the printing plate. The heat treatment conditions are the same as the heat treatment that the thin film transistor circuit board receives during the film formation process, and the steps from the beginning to the step of forming a film on which the pattern of the printing plate is printed are sequentially performed.
By carrying out such a treatment, the pattern initially formed on the printing plate in the dimension as designed shrinks. on the other hand,
The thin film transistor circuit pattern already formed on the thin film transistor circuit substrate also contracts when a film is formed thereon. Since the printing plate and the thin film transistor circuit board have the same degree of contraction, positional deviation can be prevented. Further, by performing the heat treatment in vacuum or in an inert gas, it is possible to prevent the metal film forming the printing plate from being oxidized.

The heat treatment step of the printing plate 11 has the effect of increasing the adhesive force between the glass substrate 1 or the transparent conductive layer 2 of the printing plate 11 and the electroplated metal layer 5 thereon. That is, the electroplated metal layer 5 has a weak adhesive force with the transparent conductive layer 2 as it is deposited and may be peeled off during the printing process, but is not peeled off after the heat treatment process. It should be noted that at least 200 is required to improve the adhesive strength.
Although heat treatment at 1 ° C. is required for 1 hour, if the heat treatment conditions in the thin film transistor circuit manufacturing process are not more than this, the heat treatment under these conditions can be performed on the printing plate. With such heat treatment, the glass substrate hardly shrinks. In this way, the printing plate 11 having a pattern of desired dimensions can be obtained.

FIG. 2 is a cross-sectional view showing in sequence the steps of forming a pattern on a thin film transistor circuit substrate using the printing plate of the present invention. In the figure, reference numeral 11 indicates a printing plate, and A indicates ink. First, as shown in FIG. 2A, a pattern forming layer 22 on which a pattern is to be formed later by etching is formed on a glass substrate 21, and a photoresist layer 23 having adhesiveness is formed thereon. Circuit board 2
Prepare 4.

On the other hand, as shown in FIG. 2B, the printing plate 1
After filling the UV-curable ink A into the concave portion of the surface of No. 1, U
The ink A is cured by irradiation with V light. Here, curing of the ink by UV light irradiation does not mean complete curing, but curing to the extent that fine patterns can be formed with the required accuracy by reducing ink dripping. further,
In the printing plate 11 formed of a transparent conductive film as the conductive layer 2 of the printing plate 11, the ink A can be cured by irradiating UV light from the back surface. Therefore,
When the UV curable ink A to be used is difficult to pass UV light and the surface does not easily cure even when irradiated with UV light, UV ink is also irradiated from the substrate side of the printing plate 11 to cure the ink A. It is possible to do so, which is preferable. Ink A having a low viscosity can also be used. By doing so, it is possible to perform printing with less dripping of the ink A in the step of transferring the ink A to the printing medium, and it is possible to perform high-definition printing.

Next, as shown in FIG. 2C, the surface of the adhesive photoresist layer 23 of the circuit board 24 and the printing plate 1
The circuit board 24 and the printing plate 11 are superposed at a predetermined alignment position so that the surface of the ink 1 filled with the ink A is in contact. Subsequently, as shown in FIGS. 2D and 2E, the circuit board 24 and the printing plate 11 are bonded together by applying pressure with a roll or the like. After that, when the circuit board 24 and the printing plate 11 are peeled off, the ink A is removed from the printing plate 1 as shown in FIG.
1 is transferred onto the adhesive photoresist layer 23 of the circuit board 24 to form a pattern on the circuit board 24. When performing such printing, the conductive layer 2 formed on the printing plate 11 is grounded, or the conductive layer 2 and the thin film transistor circuit substrate 24 of the ink transfer partner.
It is possible to prevent damage to the thin film transistor due to generation of static electricity by directly electrically connecting to a predetermined portion of the.

[0036]

【Example】

(Example 1) An intaglio plate was manufactured. As the substrate of the printing plate, the same material as that of the substrate for forming the thin film transistor circuit was used, and the same annealing treatment was performed. Thickness × length × width = 1.1 × 40
0x400mm low expansion glass (Corning # 70
59) A plate was used. IT which is a transparent conductive film on this substrate
The O film was formed by the sputtering method. The film thickness was about 0.2 μm and the sheet resistance was about 10 Ω / cm. Next, a photoresist (AZLP-15 manufactured by Hoechst Co., Ltd.) was applied onto the ITO with a spin coater so that the dry film thickness was 10 μm.
A photomask including a test pattern of a thin film transistor circuit (line width 5 to 50 μm) was contact-exposed to this photoresist, and then developed to form a photoresist pattern (line width 5 to 50 μm). Next, the substrate is immersed in a nickel electroless plating solution (Nimden LPX manufactured by Uemura Kogyo Co., Ltd.), and at the same time, a voltage is applied to electroplate nickel to a thickness of about 2 μm, after which the voltage application is stopped and nickel is removed. Electroless plating was performed to a thickness of about 6 μm. The photoresist is stripped with a dedicated stripping solution, washed with water and dried, then at about 1 ° C at 230 ° C.
By heating for a period of time to improve the adhesion between the ITO layer and the nickel layer, the intended intaglio plate was obtained. In the obtained printing plate (intaglio), the pattern of the nickel recesses had a line width of 5 to 50 μm.
The accuracy was within ± 0.5 μm. The edition depth is 8.
It was 0 ± 0.5 μm.

A release layer of silicone oil was formed on the surface of this printing plate, and then a UV curable black ink of acrylic resin type was filled. UV from the front and back of the printing plate
Light was applied to cure the ink. From the printing plate thus filled with ink, the ink was transferred to the thin film transistor circuit substrate as the printing medium as follows. First, a circuit board was prepared in which a layer requiring pattern etching was formed on a glass substrate for a thin film transistor circuit, and an adhesive photoresist was applied on the layer.
The conductive layer of the printing plate was grounded, and the circuit board was superposed while the adhesive photoresist of the circuit board and the ink-filled surface of the intaglio plate were aligned with a predetermined alignment position. continue,
Both were adhered by pressing with a roll. After that, when the printing plate and the circuit board were separated, the ink A was separated from the printing plate and transferred to the adhesive photoresist. No ink dripping was observed on the circuit board on which the pattern was formed in this manner.

(Example 2) A planographic intaglio plate was prepared. A metal film was attached to the glass substrate to form an electrically conductive layer for electroplating. That is, as the printing plate substrate, a glass plate having the same low expansion coefficient as in Example 1 was used, and copper was 0.3 μm by the sputtering method.
m formed. Next, apply photoresist to a dry film thickness of approximately 3.5μ.
It was coated to a thickness of m. The photoresist is made by Tokyo Ohka,
OMR-85 was used. After the test pattern is exposed and developed, the substrate is immersed in a copper electroless plating solution (Uemura Kogyo Co., Ltd., Sulcup ELC-SR), and at the same time, a voltage is applied to electroplate copper to a thickness of about 0.1 μm. After that, the voltage application was stopped and copper was electroless plated to a thickness of about 2.8 μm. After washing with water, the thickness of nickel is about 0.5 μm.
Electroless plated. After removing the resist, the same heat treatment as in the film forming step of the thin film transistor circuit was performed to obtain a printing plate having a pattern formed by plating formed on a glass substrate. In the obtained printing plate, the plating pattern had an accuracy of ± 0.3 μm from the line width of 3 to 50 μm, and the plate depth was 3.4 ± 0.1 μm.

[0039]

As described above, according to the present invention, it is possible to obtain an intaglio plate or plano intaglio plate having a fine pattern using a glass substrate as a substrate and using a pattern plating method as a method for forming a convex pattern. . Further, by using the electroless plating method as the pattern plating method, it is possible to reduce unevenness of the plate depth and to make the ink thickness constant. Therefore, a fine pattern such as a thin film transistor circuit can be etched with high accuracy, miniaturization can be promoted, and yield can be improved.

By making the linear expansion coefficient of the glass substrate used as the substrate of the printing plate and the expansion and contraction behavior at the time of heat treatment to be the same as that of the substrate to be printed, the substrate to be printed can be repeatedly used, for example, in a thin film transistor circuit. In the case where the pattern formed thereon is also shrunk by being heated, and the pattern formed thereon also shrinks at the same time, it is not necessary to reduce the size of the pattern to be printed later from the original printing plate, so that the economical effect is large. Furthermore, since the printing plate can easily respond to the shrinkage of the circuit board, the preliminary heat treatment of the substrate for the thin film transistor circuit, which requires a considerably long time, is
More cases will be available in a short time. Further, in some cases, there is an advantage that the preliminary heat treatment becomes unnecessary.

Further, by forming a conductive layer on the printing plate and grounding the conductive layer or electrically connecting the conductive layer and the object to be printed, damage of the thin film transistor due to generation of static electricity is prevented from occurring in a normal clean room humidity. Therefore, the clean room can be easily managed. Further, by forming the conductive layer as a transparent conductive layer, the ink in the printing plate can be cured by irradiating UV light from the glass substrate side as well, and ink dripping can be prevented, so that a fine pattern can be printed accurately. be able to. Further, the present invention is, of course,
Regardless of the size of the printing area required, if the above-mentioned effects are required, a fine pattern other than the resist,
It can be suitably used for obtaining a plate with less unevenness of plate depth, a printing pattern with less ink dripping, and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a manufacturing example of a printing plate of the present invention in the order of steps.

2A to 2D are cross-sectional views showing an example of forming a pattern on a thin film transistor circuit substrate using the printing plate of the invention in the order of steps.

[Explanation of symbols]

1 ... Glass substrate, 2 ... Conductive layer, 3 ... Photoresist (non-plating pattern), 5 ... Metal catalyst layer (electroplating layer),
6 ... Electroless plating layer, 11 ... Printing plate, 24 ... Circuit board (printing object), A ... Ink

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C25D 5/02 B G02F 1/1343 8707-2K G03F 7/34 7124-2H // H01L 21/3205

Claims (10)

[Claims] 1. A printing plate, which is an intaglio plate or a plano-concave plate, wherein a base of the printing plate is a glass substrate, and a convex portion made of a metal layer is formed on the glass substrate by a plating method. . 2. A conductive layer is formed on the glass substrate,
The printing plate according to claim 1, wherein the conductive layer is provided with a convex portion formed of a metal layer by a plating method. 3. The linear expansion coefficient of the glass substrate and the expansion / contraction behavior when the glass substrate is heat-treated are equal to the linear expansion coefficient of the substrate of the printing medium and the expansion / contraction behavior when the substrate is heat-treated. The printing plate according to claim 1 or 2. 4. The printing plate according to claim 2, wherein the conductive layer is a transparent conductive layer. 5. A method for producing an intaglio or planographic intaglio using a plating method as a method for forming a convex portion, wherein a glass substrate is used as a substrate of a printing plate, and a non-plating pattern is formed on the glass substrate by a photolithographic method. A method for producing a printing plate, comprising forming a convex portion made of a metal layer on a portion other than the non-plating pattern by a plating method, and then removing the non-plating pattern. 6. The printing plate according to claim 5, wherein, when forming the convex portion made of the metal layer, 70% or more of the height of the convex portion is formed by an electroless plating method. Production method. 7. The manufacturing method according to claim 6,
After forming a conductive layer on the glass substrate, a non-plating pattern is formed on the conductive layer by a photolithography method, and when forming a convex portion made of a metal layer on a portion other than the non-plating pattern, first, an electric layer is formed. A plating method is used to deposit the same metal as the metal to be electroless plated to form 30% or less of the height of the convex portion, and then 70% or more of the height of the convex portion is formed by the electroless plating method. A method for producing a printing plate, comprising: 8. A method for forming a pattern, which comprises using the printing plate according to claim 2 and forming a pattern on an object to be printed with a conductive layer grounded. 9. A method for forming a pattern, which comprises using the printing plate according to claim 2 to form a pattern on the printing medium while electrically connecting the conductive layer and the printing medium. 10. Using the printing plate according to claim 4, after filling the UV-curable ink in the recess of the printing plate, the glass substrate side of the printing plate is irradiated with UV light to cure the ink,
A method for forming a pattern, characterized in that the ink is then transferred to a printing medium.