JP2007296643A - Substrate for inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a TH wiring structure which can reduce a connection resistance of upper and lower electrodes in relation to a through hole (TH) that performs connection of the upper and lower electrodes of an AL wiring cable to supply electricity to a heater in FM-BTJ, and which can reduce formation dimensions of the TH. <P>SOLUTION: The substrate for the inkjet recording head is equipped with a plurality of heating resistors which eject ink, and a wiring cable which supplies electricity to the heating resistors. The wiring cable is formed up and down via an inter-layer insulating film 104. The wiring cable is connected by the through hole 123. A through hole configuration is constituted which at least partially includes an upper and lower electrode connection form wherein at least a part of the upper electrode in the through hole 123 that is a connection point of the upper and lower electrodes formed up and down of the inter-layer insulating film 104 is not formed on the inter-layer insulating film 104 of an outer peripheral part of the through hole 123. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to various devices having a thin film matrix wiring structure, and more particularly to an ink jet recording head that ejects a desired liquid by applying energy from the outside.

  There is known an ink jet recording method in which the generation of bubbles is promoted by applying energy such as heat to the ink, the ink is ejected from the ejection port using this volume change, and this is deposited on the recording medium to form an image. It has been. Among ink jet systems, a side shooter type (Patent Document 1) that ejects ink perpendicular to a substrate has been proposed.

  12A includes a plurality of heating resistors that discharge ink, and wirings that supply power to the heating resistors are formed above and below with an interlayer insulating film interposed therebetween, and are connected through through holes. 2 is a schematic conceptual diagram of the inkjet recording head substrate before forming a heater protective film.

  The wiring for supplying power to the heater section includes an individual electrode 105 made of an upper electrode formed on the interlayer insulating film 104 with the heater 106 interposed therebetween, a lower electrode 103 formed under the interlayer insulating film, and a through hole 123. And a common electrode connected to the heater via the upper electrode. In order to efficiently supply power to the heater, it is necessary to lower the resistance of the wiring, and the total resistance of the electrode is the sum of the resistance of the wiring and the connection resistance at the through hole.

  As shown in FIG. 3, the contact resistance at the through hole increases when the contact area becomes narrower, and the contact resistance increases abruptly when the contact area becomes extremely narrow. In addition to the increase in contact resistance, if the contact area of the through hole is narrowed, the current density in the through hole increases, causing problems such as destruction of the through hole or occurrence of migration due to overcurrent. Accordingly, the through hole needs to have a certain size.

On the other hand, the ink supply capability relating to the ink ejection performance of the inkjet needs to make the distance between the ink supply port, the sacrificial layer 122 and the heater 106 as small as possible. The through hole 123 is located between the heater and the ink supply port. To reduce the distance between the ink supply port and the heater portion, it is necessary to reduce the through hole. However, if the through hole is reduced, the contact resistance increases rapidly. There is a problem of end.
JP-A-9-011479

  As described above, if the through hole is widened in order to reduce the contact resistance at the through hole portion, the distance between the ink supply port and the heater becomes long, the ink supply capability is lowered, and the ink ejection performance is deteriorated. On the other hand, if the distance between the ink supply port and the heater is narrowed, the ink supply capability is improved, but there is a problem that the through hole becomes narrow and the contact resistance increases.

  As means for solving the above problems, the configuration of the present invention is as follows.

  In an inkjet recording head substrate having wirings connected by through-holes, at least a part of the upper electrode is an outer periphery of the through-hole in the through-hole that is a connection point between the upper and lower electrodes formed above and below the interlayer insulating film. It is solved by having at least a part of the upper and lower electrode connection form not formed on the interlayer insulating film of the part, or having at least a part of the upper and lower electrode connection form in which the upper electrode is not formed in the tapered portion of the through hole. The

  This is solved by the fact that the minimum dimension of the through-hole dimension is formed to be equal to or twice the minimum line width.

The device area is applied to a device substrate having a device area of 200 to 1000000 mm ² or a device size of 100 to 1000 mm or more.

[Experiment of the present invention]
The contact areas of the connection shape in the through hole of the present invention and the connection shape in the conventional through hole were compared.

  As a premise, the dimensions in the Y direction are the same, and the upper electrode in the X direction is not formed on the interlayer insulating film in the outer peripheral portion of the through hole. In this description, the upper electrode does not cover the tapered portion of the through hole. The structure. FIG. 1 shows a plan view of the through hole of the present invention.

  The through hole structure of the present invention is a structure in which the upper electrode is not formed on the interlayer insulating film in the outer peripheral portion of the through hole, and is not limited to the X direction (that is, one direction) described here. 1-b, the upper electrode may not be formed on the interlayer insulating film in both XY directions, and the through-hole may be circular instead of square as shown in FIG. 1-c. There are also polygonal and free shapes.

  The lower electrode 103 or the lower electrode 103 of the present invention is an electrode formed before the interlayer insulating film is formed. It is formed under the interlayer insulating film 104. In the through hole, the interlayer insulating film on the lower electrode is removed. Next, the upper electrode 105 or the upper electrode 105 is an electrode formed on the interlayer insulating film 104, and is an electrode formed on the lower electrode 103 in the through hole. On the process, it is an electrode formed after the formation of the interlayer insulating film.

  The dimension in the X direction required for connecting the upper and lower electrodes at the through hole was evaluated. The overlay accuracy of pattern formation is ± M μm, and the X-direction dimension of the tapered portion of the through hole is T μm.

  In order to ensure the connection dimension A of the upper and lower electrodes in the through hole, the conventional shape takes into consideration the overlap margin of the through hole and the overlap margin of the upper electrode as shown in FIG. If the width is 2M, an M + 2M + 2M space is required on the left side. On the right side, an overlap margin M of the through hole is required, and furthermore, T is necessary at both ends at the tapered portion of the through hole.

  Therefore, in order to secure the connection dimension A, A + 6M + 2T is required in the X direction, which is defined as the through hole X direction dimension TH_X.

  If the connection dimension A is 10 μm, the overlay margin M is 1.5 μm, and the through hole taper T is 1 μm, TH_X is 21 μm in total.

  On the other hand, in the through hole shape of the present invention shown in FIG. 2A, in consideration of the overlay margin of the upper electrode in the through hole, the X-direction dimension of the bottom surface of the through hole is increased by 2M to A + 2M. The dimension in the X direction is A + 4M + 2T. If the connection dimension A is 10 μm, the overlay margin M is 1.5 μm, and the through hole taper T is 1 μm, TH_X is 18 μm in total.

  In the case of this configuration, the dimension of TH_X required as a through hole portion can be shortened by 3 μm compared to the conventional configuration.

  Next, the contact areas of the upper and lower electrodes when the upper and lower electrodes are connected within the same dimension will be compared.

  The contact areas of the upper and lower electrodes were compared when the dimension TH_X in the X direction of the through hole portion was 21 μm and the overlay margin M was changed. The taper width of the through hole was 1 μm.

  The contact dimension in the X direction is A, and Table 1 shows the contact dimension A of the through hole configuration of the present invention and the conventional through hole configuration. It can be seen that the through-hole configuration of the present invention can ensure a wider contact area. Furthermore, it can be seen that as the overlay margin becomes wider, the increasing rate of the contact dimension is improved, and that the through-hole configuration of the present invention is more advantageous as it is created by an apparatus having a larger overlay error.

「プロセス解像との関連」
同一寸法内で上下電極接続を行った場合の製造装置のプロセス解像度（具体的には露光機の解像度、ホトレジストの解像度、ウエットエッチング、ドライエッチング精度等の総合されたプロセスの解像度）と上下電極の接触面積を比較する。

"Relationship with process resolution"
Process resolution of the manufacturing equipment when connecting the upper and lower electrodes within the same dimensions (specifically, the resolution of the exposure machine, the resolution of the photoresist, the resolution of the wet etching, dry etching accuracy, etc.) and the upper and lower electrode Compare contact areas.

  The contact area of the upper and lower electrodes was compared when the dimension TH_X in the X direction of the through hole portion was 15 μm and the process resolution was changed. The taper width of the through hole was 1 μm. The overlay margin was set to 1/5 of the process resolution.

  The contact dimension in the X direction is A, and Table 2 shows A of the through hole configuration of the present invention and the conventional through hole configuration. It can be seen that the through-hole configuration of the present invention can ensure a wider contact area. Furthermore, the difference from the conventional configuration becomes more prominent as the process resolution becomes worse. The through-hole configuration of the present invention is more advantageous as the process resolution is lower, that is, the device is produced with a larger overlay error. Further, in the case of a conventional through-hole, if the process resolution is 7 μm and the through-hole size is 15 μm, it cannot be created due to the overlap margin, but it can be created in the configuration of the present invention.

  In the conventional through-hole structure, the through-hole dimension TH_X is required to be at least twice the resolution of the process apparatus. However, in the through-hole structure of the present invention, the through-hole dimension TH_X is at least 1.5 times the resolution of the process apparatus. Can be created.

「接触寸法（接触面積）と接触抵抗の関係」
接触面積Ｓ_ＴＨと接触抵抗Ｒ_ＴＨの実験を行った。実験結果を図３に示す。

"Relationship between contact size (contact area) and contact resistance"
Experiments were conducted on contact area _STH and contact resistance _RTH . The experimental results are shown in FIG.

If the contact area _{S TH} is sufficiently wide, the contact resistance _{R TH} is almost independent on the contact area _{S TH,} the contact resistance _{R TH} and the contact area _{S TH} narrows below a certain degree rapidly increases.

  Therefore, it is necessary to form the contact area as wide as possible, and the effectiveness of the through hole configuration of the present invention was confirmed.

  As described above, according to the present invention, at least a part of the upper electrode in the through hole, which is a connection portion of the upper and lower electrodes formed on the upper and lower sides of the interlayer insulating film, is formed on the interlayer insulating film in the outer peripheral portion of the through hole. By having at least a part of the upper and lower electrode connection form that is not formed, the through hole size can be shortened without increasing the contact resistance of the through hole, so the distance between the ink supply port and the heater can be reduced. Ink supply capacity has been improved and ejection performance has been improved.

  Since the contact area of the upper and lower electrodes in the through hole can be widened, the through hole can be prevented from being broken due to an increase in current density due to the narrow contact area of the through hole, or disconnection due to migration due to overcurrent, and reliability Was able to produce an ink jet head improved.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  Embodiments of the present invention will be specifically described below based on examples, but the present invention is not limited to the following examples.

  Hereinafter, the process flow of the inkjet recording head substrate according to the present invention will be described with reference to FIGS. 4-1 to 4-5 and FIGS. 13-1 to 13-4.

A silicon (Si) substrate 101 having a substrate surface orientation (110) or (100) of 625 μm in thickness and 6 inches Φ (which will be described using the substrate orientation (100) substrate in this sectional view) is thermally oxidized as an insulating film. A thermal oxide film (SiO ₂ ) 102 was formed in a thickness of 10,000 mm (FIG. 4A), and the thermal oxide film in the supply port opening portion (portion for forming the etching stop layer) 121 was removed by using a photolithography technique.

  In this embodiment, a 6-inch Φ silicon substrate is used for explanation. However, the wafer shape and size are not limited, and a square or rectangular silicon substrate may be used, and the size is not limited.

As the insulating film, silicon nitride (SiN) or the like may be used in addition to the thermal oxide film (SiO ₂ ). Further, the production method is not limited to the thermal oxidation method, but may be an LPCVD method or an atmospheric pressure CVD method.

  A 3000-thick AlCu film was deposited by sputtering and patterned by photolithography as shown in FIG. 4-2 to form a sacrificial layer 122 and a common electrode (lower electrode) 103. The width of the sacrificial layer was 120 μm, and the long side direction was 15 mm.

  When the etching progresses from the back surface and the etchant reaches the sacrificial layer, the sacrificial layer is etched in a short time because the etching rate is much faster than that of the silicon wafer, and an opening corresponding to the sacrificial layer pattern can be opened. is there.

  In this embodiment, AlCu is used as the sacrificial layer, but Al, an alloy of Cu and Si, amorphous silicon by plasma CVD, polycrystalline silicon, porous silicon by anodization, silicon dioxide obtained by oxidizing porous silicon Etc. may be used.

  Next, 14000 mm of silicon nitride film 104 was deposited by plasma CVD as an etching stop layer and an interlayer insulating film.

  The film thickness of the etching stop layer is 2000 to 2 μm, more preferably 6000 to 15000 mm.

The film stress of the etching stop layer is from compressive stress −3 × 10 ⁹ dyne / cm ² to tensile stress + 3 × 10 ⁹ dyne / cm ² , more preferably from compressive stress −2 × 10 ⁹ dyne / cm ^2. + 2 × 10 ⁹ dyne / cm ² , optimally from compressive stress −1 × 10 ⁹ dyne / cm ² to tensile stress + 1 × 10 ⁹ dyne / cm ² .

  In addition, a silicon nitride film having a film stress within the above range, an etching rate of TMAH (22%, 83 ° C.) of 500 Å / hr or less, and an etching rate of BHF of 200 Å / min or less is formed by plasma CVD. did.

  The conditions for forming a silicon nitride film by plasma CVD in this embodiment will be described.

SiH ₄ , NH ₃ , and N ₂ were used as source gases, the flow rates were 200, 100, and 2000 sccm, the discharge pressure was 1.5 Torr, the RF power was 1000 W, and the deposition temperature was 300 ° C.

The film stress of silicon nitride is compression −2 × 10 ⁹ dyne / cm ² , the etching rate of TMAH (22%, 83 ° C.) is 130） / hr, the etching rate of BHF is 190 Å / min, and the refractive index is 1. 88.

  In this embodiment, an example of the film formation condition of silicon nitride by plasma CVD is shown. However, if the film stress, the etching rate of TMAH (22%, 83 ° C.), and the etching rate of BHF satisfy the conditions described above. It ’s fine.

Further, the deposition temperature is preferably 250-400 ° C, optimally 300-350 ° C. Further, the source gas of the silicon nitride film by plasma CVD is not limited to the combination of SiH ₄ , NH ₃ , and N ₂ described in this embodiment, but a combination of SiH ₄ , NH ₃ , N ₂ , and H ₂ . (SiH ₄ / NH ₃ / N ₂ / H ₂ , SiH ₄ / NH ₃ / N ₂ , SiH ₄ / NH ₃ / H ₂ , SiH ₄ / N ₂ , SiH ₄ / H ₂ / N ₂ , SiH ₄ / NH ₃ ) may be used.

  Next, as shown in FIG. 4C, the silicon nitride film was patterned by photolithography to form a through hole 123. Note that the taper angle of the through hole was 60 ° or less.

  Next, by sputtering, a TaN film having a thickness of 500 mm and an Al film having a thickness of 2500 mm are continuously formed, and patterning is performed. A heater unit 106 and individual electrodes 105 are formed as ink discharge pressure generating elements in accordance with the ink supply ports (FIG. 4-4). ).

  The individual electrode, common electrode, lower electrode, and upper electrode in this embodiment will be described.

  The individual electrode is an electrode for individually supplying electric power to the heater, and the common electrode is an electrode connected in common when driven in block units. Further, as described in the experimental section, the upper electrode is an electrode formed after the interlayer insulating film is formed, and the lower electrode is an electrode formed before the interlayer insulating film is formed.

  The lower electrode is a common electrode, a part of the upper electrode is an individual electrode, and functions from the heater to the through hole as a common electrode.

  As a heater material, in addition to TaN, a metal film such as Ta or TaNSi may be deposited by sputtering or vacuum evaporation. Further, as an individual electrode for supplying power, a metal film such as Mo or Ni may be formed in the same manner in addition to Al.

  Here, the through-hole configuration of the first embodiment of the present invention will be described.

  FIG. 5 is a plan view of the through hole before the heater protective film is formed, FIG. 6 is an enlarged view of the through hole before the heater protective film is formed, and FIG. 7 is a sectional view of the through hole before the heater protective film is formed.

  As shown in the figure, the through hole portion of the present embodiment is configured such that the upper electrode is not formed on the upper part of the interlayer insulating film on the left side of the through hole. As described in the experimental section, the heater portion 106 and the ink supply port 126, the distance from the sacrificial layer 122 can be shortened, and the contact area of the upper and lower electrodes in the through hole can be increased, so that the contact resistance of the upper and lower electrodes can be reduced.

  Next, as shown in FIG. 4-5, a protective film 107 was attached to the heater 106 for the purpose of improving durability.

The protective film is required to be excellent in heat resistance, liquid resistance, liquid penetration prevention, oxidation stability, insulation, puncture resistance and thermal conductivity, and inorganic compounds such as SiO ₂ or SiN are generally used. It is done. In this embodiment, 2000 nm of silicon nitride film formed by plasma CVD was formed as the protective film and patterned.

  Furthermore, the protective film of a single layer may be insufficient for the protection of the heating resistor layer, and a layer of metal such as Ta having higher cavitation resistance may be formed on the protective film.

Next, the thermal oxide film (102) on the back surface of the wafer was removed using a photolithography technique, the wafer surface was exposed, and an ink supply portion 124 on the back surface was formed. (Fig. 13-1)
A nozzle forming process for discharging ink will be described.

  As a photosensitive resin, polymethyl isopropenyl ketone (Tokyo Ohka ODUR-1010) was applied by 20 μm and patterned to form an ink flow path mold 108 as shown in FIG. 13-2. Further, a photosensitive resin layer of 10 μm was applied as a nozzle forming material 109 and patterned to form an ink discharge port 125.

The photosensitive resin is (1) epoxy resin (o-cresol type epoxy resin)
Yuka Shell Epicote 180H65) 100 parts Epicote is a registered trademark.

(2) Photocationic polymerization initiator (44 'di-t-butylphenyl iodonium
Hexafluoroantimonate) 1 part (3) Silane coupling agent Nippon Unicar A187 10 parts.

In order to protect the nozzle forming surface side, a protective film 110 was formed with a rubber-based resist (OBC manufactured by Tokyo Ohka Kogyo Co., Ltd.). (Figure 13-2)
This substrate was immersed in 20% TMAH aqueous solution and anisotropically etched. The etchant temperature was 83 ° C. and the etching time was 12 hours. This was an overetching time of 10% with respect to the time for just etching the thickness of the substrate of 625 μm. (Fig. 13-3)
In this embodiment, TMAH is used as the anisotropic etching solution, but an etching solution such as an aqueous potassium hydroxide solution, EDP, or hydrazine may be used.

Next, p-SiN which is an etching stop layer was removed by RIE. The etching conditions were SF ₆ / O ₂ 200/40 sccm RF 800 W, pressure 20 mTorr. Next, after being immersed in methyl isobutyl ketone, the protective film 110 was removed by applying ultrasonic waves in xylene.

  As shown in FIG. 13-4, the resin 108 was removed by applying ultrasonic waves in methyl lactate to form the ink flow path 127, and an ink jet recording head was completed.

  Using this ink jet recording head, a printing test was performed at an ejection frequency of 10 KHz, but the distance from the heater part and the ink supply port could be shortened, and the contact area of the upper and lower electrodes in the through hole could be increased. The contact resistance of the upper and lower electrodes could be reduced, and a high-quality printed matter free from printing blur, density unevenness, and non-ejection of ink was obtained over the entire 15 mm width.

  In the following, another embodiment of the present invention will be described.

  In the second embodiment, a Si substrate having a plane orientation (110) was used as the substrate.

  As for the planar shape of the ink supply port, when a plane orientation (100) substrate of a silicon wafer is used, the pattern is arranged in a rectangle as shown in FIG. Also, when using a substrate plane orientation (110) substrate, the pattern is a parallelogram with a narrow angle of 70.5 degrees as shown in FIG. The long side and the short side of the parallelogram are arranged so as to be parallel to a plane equivalent to (111).

  A production flow of the ink jet recording head of the second embodiment of the present invention is shown in FIGS.

In the same manner as in Example 1, a thermal oxide film (SiO ₂ ) was formed on the wafer and patterned, and AlCu was formed and patterned as a lower electrode and a sacrificial layer.

  Next, 18000 mm of a silicon nitride film was deposited by plasma CVD as a film that also serves as an etching stop layer and an interlayer insulating film.

  Contact holes were formed in the interlayer insulating film using photolithography technology.

Further, a 3000-thick Al film is formed by sputtering and patterned, and then a 500-thick TaN film is formed and patterned to form the upper electrode 205 and the heater 206. (Figure 9-1)
The through hole portion of this embodiment has a configuration in which the upper electrode is not formed on the upper part of the interlayer insulating film on the left side of the through hole 223, and as explained in the experimental section, the lower electrode is not applied to the taper of the through hole. It has a configuration. As a result, the distance from the heater portion to the ink supply port can be shortened, and the contact area of the upper and lower electrodes in the through hole can be increased, so that the contact resistance of the upper and lower electrodes can be reduced.

  Polymethylisopropenyl ketone (Tokyo Ohka ODUR-1010) as a photosensitive resin was applied by 20 μm and patterned to form an ink flow path mold material. Further, a photosensitive resin layer having a thickness of 10 μm was applied and patterned to form an ink discharge port 225.

In order to protect the nozzle forming surface side, a protective film was formed with a rubber-based resist (OBC manufactured by Tokyo Ohka Kogyo Co., Ltd.). The back side ink supply port 224 was formed by patterning the SiO ₂ on the back side of the nozzle. (Figure 9-2)
This substrate was immersed in 20% TMAH aqueous solution and anisotropically etched. The etchant temperature was 83 ° C. and the etching time was 12 hours. This was an overetching time of 10% with respect to the time for just etching the thickness of the substrate of 625 μm.

  Next, the silicon nitride layer which is an etching stop layer was removed by CDE.

The etching conditions for CDE were CF ₄ / O ₂ / N ₂ = 300/250/5 sccm, RF 800 W, and pressure 250 mTorr.

  The ink flow path 227 was formed by applying ultrasonic waves in methyl lactate to remove the resin. Finally, as shown in FIG. 9-4, after being immersed in methyl isobutyl ketone, ultrasonic waves were applied in xylene to remove the protective film, and an ink jet recording head was obtained.

  Using this ink jet recording head, a printing test was performed at an ejection frequency of 10 KHz, but the distance from the heater part and the ink supply port could be shortened, and the contact area of the upper and lower electrodes in the through hole could be increased. The contact resistance of the upper and lower electrodes could be reduced, and a high-quality printed matter free from printing blur, density unevenness, and non-ejection of ink was obtained over the entire 15 mm width.

  This embodiment is an example in which a TFT substrate applied to an organic EL display device is manufactured, and FIG. 10 schematically shows a section around a TFT using a through-hole structure according to this embodiment.

  The present invention is not limited to an organic EL legal apparatus, and relates to a matrix-driven organic EL display device, a TFT-driven liquid crystal display device, a matrix-driven liquid crystal display device, and other devices that can take the through-hole configuration of the present invention. Is.

In this embodiment, the gate electrode 302, the gate insulating film 303, the a-Si: H film 304, the n ⁺ type a-Si: H film 305, the source electrode 306, the drain electrode 307, and the transparent pixel electrode 308 made of an ITO film. A pattern was formed by a film forming technique, a photolithography technique, and dry etching. A poly-Si film may be used instead of the a-Si: H film.

  In the present embodiment, the through-hole configuration of the present invention is adopted for the through-hole that is a connection portion of the upper and lower electrodes.

  Next, the organic EL layer 309 and the upper common electrode 310 of the organic EL element were formed by vacuum deposition in a state where a metal mask was provided on the entire pixel region. This upper electrode is made of, for example, a magnesium film containing silver.

Thereafter, for the purpose of improving the reliability, for example, a protective film 311 of SiN _x is formed as needed to constitute an organic EL display.

  When the organic EL display is driven by an active matrix circuit, a set of thin film transistors for controlling the current supplied to each pixel is connected to each pixel of the organic EL as shown in FIG. ing.

  That is, the organic EL display driven by the active matrix circuit includes an X direction signal line 401, a Y direction signal line 402, a power supply line 403, a switching thin film transistor 404, a current control thin film transistor 405, an organic EL element 406, and an X direction peripheral drive. Circuit, Y direction peripheral drive circuit, and the like.

  In the above configuration, when the Y direction signal line 402 is selected and the switching thin film transistor 404 is turned on, the voltage of the X direction signal line 401 is supplied to the capacitor (charge holding capacitor) 407 through the switching thin film transistor 404.

  When the Y direction signal line 402 is in a non-selected state, the switching thin film transistor 404 is turned off, and the voltage of the X direction signal line 401 is held in the capacitor (charge holding capacitor) 407.

  The terminal voltage of the capacitor (charge holding capacitor) 407 is applied between the gate and source of the current control thin film transistor 405, and the current according to the gate voltage and drain current characteristics of the current control thin film transistor 405 is changed from the power supply line 403 to the organic EL. The organic EL element 406 emits light through a path of the element 406 → the current control thin film transistor 405 → the Y-direction signal line 402.

  At this time, if the relationship between the luminance of the organic EL element and the voltage applied to the capacitor is known, the organic EL element can emit light with a predetermined luminance.

  The through-hole structure of this example is a structure in which the upper electrode is not formed on at least a part of the insulating film on the outer periphery of the through-hole, so that the connection area can be widened, and the connection resistance is reduced. Display unevenness due to variations in wiring resistance was reduced, and a good display device was obtained.

  In addition, since the through-hole structure of the present embodiment can be created with the size of one side of the through-hole and about 1.5 times the resolution of the manufacturing apparatus, the through-hole occupation area is reduced, the substantial display area is enlarged, and the display quality is increased. Improved.

  Moreover, since a cheaper apparatus can be used, the cost was reduced.

Plan view of the through hole portion of the present invention Through hole X (XX ') direction cross section Through hole contact area and contact resistance Example 1 of the Invention Inkjet recording head Manufacturing flow diagram Example 1 of the present invention A plan view of an ink jet recording head before forming a heater protective film The top view of the through hole of Example 1 of this invention Sectional drawing of the through hole of Example 1 of this invention (8-1) The sacrificial layer plan view of the first embodiment of the present invention. (8-2) Sacrificial layer of the second embodiment of the present invention Plan view Manufacturing flow diagram of inkjet recording head of Example 2 of the present invention The schematic diagram which shows the cross section around TFT of a TFT substrate applied to the organic electroluminescence display concerning Example 3 of this invention, and a through-hole. Explanatory drawing of the organic electroluminescence display concerning Example 3 of this invention. Conventional example Plan view of the inkjet recording head before forming the heater protective film Example 1 of the Invention Inkjet recording head Manufacturing flow diagram

Explanation of symbols

101 Si substrate 102 Thermal oxide film 103 Lower electrode or common electrode 104 Interlayer insulating film 105, 205 Individual electrode 106, 206 Heater 107 Protective film 108 Ink flow channel material 109 Nozzle forming material 110 Protective film 121 Supply port opening 122 Sacrificial layer 123 , 223 Through hole 124, 224 Ink supply portion 125, 225 Ink discharge port 126, 226 Ink supply port 127, 227 Ink flow channel 201 Si substrate 204 Sacrificial layer 301 Substrate 302 Gate electrode 303 Gate insulating film 304 a-Si: H film 305 n ⁺ -type a-Si: H film 306 source electrode 307 drain electrode 308 a transparent electrode 309 organic EL layer 310 upper common electrode 311 protective film 401 X-direction signal lines 402 Y-direction signal lines 403 power line 404 membrane switch transients Tha 405 current controlling TFT 406 organic EL device 407 Kondensa

Claims (4)

In an inkjet recording head substrate having wiring connected by through holes,
At least one of the upper and lower electrode connection forms in which at least a part of the upper electrode in the through hole, which is a connection point of the upper and lower electrodes formed above and below the interlayer insulating film, is not formed on the interlayer insulating film in the outer peripheral portion of the through hole. A substrate for an ink jet recording head, comprising: a portion. In an inkjet recording head substrate having wiring connected by through holes,
At least a part of the upper electrode in the through hole, which is a connection part of the upper and lower electrodes formed above and below the interlayer insulating film, has at least a part of the upper and lower electrode connection form not formed in the tapered part of the through hole. An inkjet recording head substrate.   2. The substrate for an ink jet recording head according to claim 1, wherein a minimum dimension of the through hole dimension is equal to or twice the minimum line width. The inkjet area of the substrate for recording head 200 mm ² or more 1000000Mm ² or less, or a substrate for an ink jet recording head according to any one of claims 1 to 3, device dimensions, characterized in that at least 100mm 1000mm or less.

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