JP2000135792A - Ink jet head, its production, and ink jet apparatus equipped with ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it hard to receive the effect of the shift of meshes at the time of formation of respective layers and to enable excellent energy conservation/emission stabilization by providing an area where a protective film is locally thin inside the connection parts of heating resistors and wirings and providing recessed parts between the heating resistors and bringing flow passage walls into contact with a substrate through the bottom surface thereof. SOLUTION: An area 107 where a protective film is locally thin is provided in a substrate 104 inside the connection parts of heating resistors 105 and electrode wirings 106 and recesses equipped with the bottom surfaces for the contact with flow passage walls 108 are formed between the heating resistors 105 so as to be positioned below a heat acting surface. A first protective film 107A and a second protective film 107B are formed simultaneously when only one layer of a two-layered protective film is removed by patterning. By this constitution, the effect of the shift of meshes, over-etching and step coverage at the time of formation of respective layers is made hard to receive and the recesses can be formed precisely and power consumption can be reduced and good emission stability is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet head for recording by discharging ink from a discharge port by the growth and contraction of bubbles generated in the ink by a discharge energy generating element, a method for manufacturing the same, and this ink-jet head. The present invention relates to an ink-jet device provided.

[0002]

2. Description of the Related Art Ink jet recording systems have attracted attention in recent years because they are capable of high-speed, high-density, high-precision, high-quality recording, and are suitable for colorization and compactness.
(US Pat. No. 4,723,129, US Pat. No. 47407)
No. 96).

As shown in FIGS. 1 and 2 (a cross-sectional view taken along the line AA in FIG. 1), a head used for the above-described ink jet recording is provided with a plurality of discharge ports 101. An electrothermal conversion element 102 that generates thermal energy used to discharge ink (hereinafter referred to as ink) is provided on a substrate 104 for each ink flow path 103. Each electrothermal conversion element 102 mainly includes a heating resistor 105 and an electrode wiring 106 for supplying power to the heating resistor 105.
And a protective film 107 for protecting them. In addition, each ink flow path 103 aligns the top plate 110 on which a plurality of flow path walls 108 are integrally formed with the electrothermal conversion element 102 and the like on the substrate 104 by means such as image processing. It is formed by joining while performing. Each ink flow path 103 has an end opposite to the discharge port 101 communicating with a common liquid chamber 109.
Stores ink supplied from an ink tank (not shown). The ink supplied to the common liquid chamber 109 is guided to the respective ink channels 103 from here, and forms a meniscus near the ejection port 101 and is held. At this time, by selectively driving the electrothermal conversion element 102, the ink on the heat acting surface is rapidly heated and foamed by utilizing the generated thermal energy, and the ink is ejected by the foaming.

Meanwhile, the thermal action surface of the ink jet recording head is exposed to mechanical shock caused by cavitation due to repetition of foaming and defoaming of the ink, and furthermore to erosion.
It is placed in a harsh environment such as being exposed to a temperature rise and fall of around 1000 ° C. in a very short time of microseconds. Therefore, the protective film 107 is required to have excellent heat resistance, liquid resistance, liquid permeation prevention, oxidation stability, insulation, damage resistance and heat conductivity. As described above, in the inkjet recording head, the configuration of the protective film 107 is an important factor that determines the performance of the head, for example, power consumption and life.

Further, since the ink flow path 103 is formed by joining the top plate 110 and the substrate 104, a displacement occurs between the top plate 110 and the substrate 104, and each flow path wall 108 and the substrate 104 When a gap is formed between the flow path wall and the joining surface, the ink pressure wave is transmitted to the adjacent ink flow path, and the ejection becomes unstable due to the escape of foaming energy to the adjacent ink flow path. As described above, in the ink jet recording head, the bonding between the top plate 110 and the substrate 104 is also an important point.

[0006] As shown in FIG.
A structure in which the protective film 107 has a locally thin region 107 ′ inside the connection portion between the electrode and the electrode wiring 106, and has a bottom surface located below the heat acting surface between the heating resistors 105 as shown in FIG. An ink-jet head having a concave portion and a configuration in which the flow path wall 108 is in contact with the substrate 104 at the bottom surface has been attracting attention from the viewpoints of energy saving, ejection stability, and the like (Japanese Patent Application Laid-Open Nos. 8-112902, 7-112). -89073).

[0007]

However, in the former ink jet recording head, when each ejection port 101, that is, each heating resistor 105 comes close to each other due to high density and multiple nozzles, heat between adjacent heating resistors 105 is generated. The influence of crosstalk starts to occur, and the temperature rise causes a change in ejection characteristics.

Also, in the latter ink jet recording head, the shape of the bottom surface located below the heat-acting surface, where the flow path wall 108 contacts, is affected by misalignment, over-etching, step coverage, etc. when forming each layer. Easy to vary. Therefore, when forming a large number of bottom surfaces with a narrow width by increasing the number of high-density nozzles, it is difficult to secure a stable area due to variations in the formation, and the top plate 110 and the substrate 104
However, there is a problem in that the ink cannot be successfully joined, and ink cross-talk occurs between adjacent flow paths.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, the protective film was locally thinned inside the connection between the heating resistor and the electrode wiring. And forming a recess between the heating resistors below the heat acting surface and having a bottom surface for the flow path wall to abut against, by using only one layer of the two-layered protective film. By performing simultaneously when removing the patterning, even if a large number of heating resistors are close to each other due to high density and multiple nozzles,
The present invention has been completed by finding that an ink jet recording head excellent in energy saving and ejection stability can be obtained. The present invention provides a plurality of heating resistors for applying heat to ink, and an electrical connection between the heating resistors. A substrate having a wiring that is electrically connected, a heating film for protecting the heating resistor and the wiring, and a protection film provided on the wiring,
A wall member integrally joined to the substrate and having a plurality of flow path walls forming a flow path for discharging heat by applying heat generated by the heating resistor to the ink; and And the wall member is joined to form the flow path, wherein the substrate has a region where the protective film is locally thinner inside a connection portion between the heating resistor and the wiring. And a concave portion between the heat generating resistors, the concave portion forms a bottom surface located below a heat acting surface that transmits heat to ink, and the flow path wall contacts the substrate at the bottom surface. An ink jet head is proposed, wherein the protective film is composed of two protective films having different selectivity, and an upper layer SiN of the protective film is provided.
In the film, the lower layer includes a SiO film.

Further, the present invention provides a plurality of heating resistors for applying heat to the ink, a wire electrically connected to the heating resistor, and a wire for protecting the heating resistor and the wire. A substrate having a heating resistor and a protective film provided on the wiring; and a flow bonded to the substrate and forming a flow path for discharging heat by applying heat generated by the heating resistor to the ink. A wall member integrally having a plurality of road walls, wherein the flow path is formed by joining the substrate and the wall member, wherein the heating resistor and the A step of forming a protective film on the wiring, and a step of locally thinning the protective film inside a connection portion between the heating resistor and the wiring so as to have a concave shape between the heating resistors. A recess provided on the flow path wall and the substrate And a step of aligning the flow path and the heat generating resistor by joining them together. The method for manufacturing an ink jet head, wherein a selection ratio is selected in the step of forming the protective film. Forming two protective layers different from each other, and removing one of the protective films in the step of thinning the protective film. The step of removing the protective film is performed by selective etching between the two protective films. And performing the selective etching using hot phosphoric acid using an upper layer of the protective film and a lower layer of an SiON film.

Further, the present invention proposes an ink-jet apparatus comprising at least the above-described ink-jet head and a member for mounting the recording head.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is not limited to the following embodiments, but may be any as long as the object of the present invention can be achieved.

[0013]

FIG. 5 is a plan view of a substrate of a heat generating portion for bubbling ink of an ink jet recording head according to an embodiment of the present invention, and FIG. 6 is a dashed line XX 'shown in FIG. FIG. 7 is a partial cross-sectional view taken along the line YY ′ shown in FIG. 5 and perpendicular to the substrate surface.

According to the present embodiment, the substrate for the heat-generating portion is prepared in S
An i-substrate or a Si substrate in which a driving IC has already been fabricated is used. First, the heat storage layer 117 formed by thermal oxidation or the like is formed on the substrate 104. On top of this, Al, Cu, Al
Common electrode wiring 116 made of -Si, Al-Cu or the like was formed by a sputtering method. Next, a wiring pattern is formed by using a photolithography method, and etching is performed by a reactive ion etching method.
16 was completed. An interlayer insulating film 113 made of SiO ₂ or the like is formed thereon by a sputtering method, a CVD method, or the like. Next, TaN, Ta is formed by reactive sputtering.
Heating resistance layer 105 made of SiN or the like, Al, Cu, Al
-An individual electrode wiring layer 114 made of Cu, Al-Si or the like is formed. Next, a wiring pattern is formed by using a photolithography method, and Al, T is formed by a reactive ion etching method.
Etching is performed continuously with aN. In order to expose the heating part again by the photolithography method as shown in FIG. 5,
Al is removed by wet etching. This portion becomes the heating resistor. Next, a first protective film SiO and a second protective film SiN are formed as protective films by a plasma CVD method.
To form Next, patterning is performed using a photolithographic method, and wet etching is performed using hot phosphoric acid.
The etching was performed for 2 minutes, and the etching was completed when the SiN layer was etched. As a result, an SiO film having a smaller etching rate than the SiN film remained. Next, a Ta film 115 was formed as a cavitation-resistant and ink-resistant film by a sputtering method.

The substrate thus obtained has a step of locally thinning the protective film inside the connection between the heating resistor and the electrode wiring, and a step of positioning the protection film between the heating resistors below the heat-working surface. The step of forming a concave portion having a bottom surface for the flow path wall to contact is performed simultaneously when patterning and removing only one layer of the two-layered protective film. Even when a large number of heating resistors are close to each other, there is less influence from overheating and step coverage during formation of each layer compared to the configuration shown in FIG. The formation of the concave portion having the bottom surface located at the position is accurately performed. In addition, using the above substrate, an ink jet head was manufactured, and the power consumption required for foaming and the stability of ejection were confirmed. As a result, the power consumption was reduced compared to the configuration in which one layer of the protective film was not removed. And the ejection stability was also good.

(Other Embodiments) FIG. 8 is an external view of an ink jet apparatus to which the present invention is applied. The driving force transmission gears 5011 and 5009 are interlocked with forward and reverse rotations of a driving motor 5013.
Spiral groove 5 of the lead screw 5004 rotating through the
The carriage HC engaged with the 005 has a pin (not shown) and is reciprocated in the direction of the arrow. 5002 is
It is a paper pressing plate, and presses the paper against the platen 5000 in the carriage movement direction. 5007,5008
Is a home position detecting means for confirming the presence of the carriage lever 5006 in this area by a photocoupler and switching the rotation direction of the motor 5013. 50
16 is a cap member 5 for capping the entire surface of the recording head.
Reference numeral 5015 denotes a suction unit for sucking the inside of the cap, and performs suction recovery of the recording head through the opening 5023 in the cap. Reference numeral 5017 denotes a cleaning blade. Reference numeral 5019 denotes a member that allows the blade to move in the front-rear direction. These members are supported by a main body support plate 5018. It goes without saying that the blade is not limited to this form and a well-known cleaning blade can be applied to the main body. Reference numeral 5012 denotes a lever for starting suction for suction recovery. The lever 5012 moves with the movement of the cam 5020 that engages with the carriage, and the driving force from the driving motor is controlled by known transmission means such as clutch switching. Is done. The capping, cleaning, and suction recovery are configured so that desired operations can be performed at the corresponding positions by the action of the lead screw 5004 when the carriage comes to the home position side area. This example can be applied to any operation. Each of the configurations described above is an excellent invention when viewed alone or in combination, and shows preferred configuration examples for the present invention. The apparatus has a drive signal supply unit for driving the ink ejection pressure generating element.

[0017]

As described above, the step of locally thinning the protective film inside the connection portion between the heating resistor and the electrode wiring, and the step of forming the flow path between the heating resistor and below the heat-working surface. Forming a recess with a bottom surface for the wall to abut,
Is performed at the same time as patterning and removing only one layer of the two-layered protective film. Therefore, even when a large number of heating resistors are close to each other due to the high-density and multiple nozzles, the protective film is conventionally removed. The pattern of the lower interlayer insulating film
Misalignment at the time of forming each layer,
It is possible to obtain an ink jet recording head which is hardly affected by bar etching and step coverage and which is excellent in energy saving, ejection stability and the like.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a conventional example of a substrate configuration of an ink jet head.

FIG. 2 is a sectional view showing a section taken along line AA of FIG. 1;

3A) is a schematic plan view showing a conventional example of a substrate configuration of an ink jet head, and FIG. 3B) is a sectional view taken on line A- of FIG. 3A).
FIG. 3c) is a schematic cross-sectional view showing a cross section taken along line A, and FIG.
It is sectional drawing which shows a line cross section.

4A) is a schematic plan view showing a conventional example of a substrate configuration of an ink jet head, and FIG. 4B) is a sectional view taken on line A- of FIG. 4A).
FIG. 4C is a cross-sectional view showing a cross section taken along line BB of FIG. 4A).

FIG. 5 is a plan view of a substrate of an inkjet head embodying the present invention.

FIG. 6 is a cross-sectional view of the substrate when FIG. 5 is cut perpendicularly by a dashed line XX ′.

FIG. 7 is a cross-sectional view of the substrate when FIG. 5 is cut perpendicularly by a dashed line YY ′.

FIG. 8 is a diagram illustrating a recording apparatus using the inkjet head of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Discharge port 102 Electrothermal conversion element 103 Ink flow path 104 Substrate 105 Heating resistor 106 Electrode wiring 107 Protective film 107 ′ Locally thin region 107A First protective film 107B Second protective film 108 Flow path wall 109 Common liquid Room 110 Top plate 111 Insulating film 112 Interlayer film 116 Common electrode wiring 117 Heat storage layer 118 Through hole 304, 113 Interlayer insulating film 306 Al layer 309, 119 Ta film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Teruo Ozaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshiyuki Imanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term (reference) 2C057 AF37 AF40 AF66 AF69 AG12 AG41 AP02 AP11 AP14 AP32 AP33 AP52 AP53 AP77 AQ02 BA05 BA13

Claims (8)

[Claims] 1. A plurality of heating resistors for applying heat to ink, wires electrically connected to the heating resistors, and the heating resistors for protecting the heating resistors and the wires. And a substrate having a protective film provided on the wiring, and a flow path wall which is bonded to the substrate and forms a flow path for ejecting heat generated by the heating resistor on the ink. An ink jet head comprising a wall member integrally having a plurality of members, wherein the flow path is formed by joining the substrate and the wall member, wherein the substrate has the heating resistor, the wiring, Inside the connection portion, the protective film has a locally thin region, and has a concave portion between the heating resistors, and the concave portion has a bottom surface located below a heat acting surface that transmits heat to ink. Forming the flow path wall to contact the substrate at the bottom surface. Characteristic inkjet head. 2. The ink-jet head according to claim 1, wherein said protective film comprises two protective films having different selectivity. 3. The ink jet head according to claim 2, wherein the protective film comprises an upper SiN film and a lower layer comprises a SiO film. 4. A plurality of heating resistors for applying heat to the ink, wires electrically connected to the heating resistors, and the heating resistors for protecting the heating resistors and the wires. And a substrate having a protective film provided on the wiring, and a flow path wall which is bonded to the substrate and forms a flow path for ejecting heat generated by the heating resistor on the ink. A method of manufacturing an ink jet head, comprising: a wall member having a plurality of members integrally; wherein the flow path is formed by joining the substrate and the wall member. A step of forming a protective film; a step of locally thinning the protective film inside a connection portion between the heating resistor and the wiring and forming a recess between the heating resistors; The road wall and the recess provided on the substrate are joined together. A method of manufacturing an ink jet head, characterized in that and a step for aligning the heat generating resistor and the channel Te. 5. The ink jet head according to claim 4, wherein in the step of forming the protective film, two protective films having different selectivity are formed, and one of the protective films is removed in the step of thinning the protective film. Manufacturing method. 6. The method according to claim 5, wherein the step of removing the protective film is performed by selective etching between two protective films. 7. The method for manufacturing an ink jet head according to claim 6, wherein the upper layer of the protective film is made of a SiN film and the lower layer is made of a SiO 2 film, and the etching is performed by selective etching using hot phosphoric acid. 8. An ink jet apparatus comprising at least the ink jet head according to claim 1, and a member for mounting the print head.