JP2001199069A - Method for manufacturing inkjet printer head and ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an ink jet printer head in which hydrophilicity can be sustained permanently in a hydrophilic region required for an orifice plate, and an ink jet printer equipped with that ink jet printer head. SOLUTION: At first, a resistor heating part 31 is provided on a head chip 29 while being surrounded by a barrier wall 23, an orifice plate 24 is placed thereon and a mask pattern 32-1 of Ti film 32 is formed thereon. An orifice 25 is bored by means of oxygen plasma 33 using a helicon wave etching system and O2 gas for processing and a Ti oxide film 32-2 is formed, as a hydrophilic region 28, on the surface of the Ti film 32. When power is turned on and when a specified number of sheets are printed or when a specified time has elapsed, the hydrophilic region 28 is irradiated with UV-rays in order to recover the aging hydrophilicity of the Ti oxide through photocatalysis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet printer head capable of maintaining the hydrophilicity of a hydrophilic region required for an orifice plate, and an ink jet printing apparatus having the ink jet printer head.

[0002]

2. Description of the Related Art In recent years, ink jet printers have been widely used. Ink jet printers include a thermal method in which ink is heated to generate air bubbles to eject ink droplets under the pressure, and a piezo method in which ink droplets are ejected by deformation of a piezoresistive element (piezoelectric element). In these methods, printing is performed by ejecting ink as a color material as ink droplets directly onto recording paper and printing is performed.Compared with the electrophotographic method using toner which is a powdery printing material, the printing energy is low, and ink Is easy to colorize, and the printing dots can be reduced, so that there are many advantages such as high image quality. Therefore, this printing method is widely used especially as a personal printer.

The above-mentioned thermal system has two configurations depending on the ejection direction of ink droplets. One type is called a side shooter type, which discharges ink droplets in a direction parallel to the heat generating surface of the heating element, and the other discharges ink droplets in a direction perpendicular to the heat generating surface of the heat generating element. This is called a roof shooter type.

FIG. 6A is a plan view schematically showing an ink ejection surface of a monocolor ink jet printer head provided in such a roof shooter type ink jet printer, and FIG. FIG. 2C is an enlarged view taken along the line AA ′, and FIG. 2C is a view showing a silicon wafer on which such an ink jet printer head is manufactured.
FIG. 1D is a diagram showing a full-color ink jet printer head having four nozzle rows.

As shown in FIG. 1C, a mono-color ink-jet printer head 1 (hereinafter, referred to as a print head 1) is formed on a silicon wafer 2 by using an LSI forming technique and a thin film forming technique. After completion, they are individually cut out from the silicon wafer 2 and collected.

As shown in FIG. 1A, a single nozzle row 3 for discharging ink is formed on the ink discharge surface of the print head 1. The nozzle row 3 has a large number of orifices 4 arranged in one vertical line at a resolution of, for example, 300 dots per 25.4 mm (about 12 density per 1 mm).

The internal structure of the print head 1 is shown in FIG.
As shown in (1), a drive circuit 6 composed of an LSI and a resistance heating section 7 composed of a thin film are formed on a chip substrate 5, and an individual wiring electrode 8 connecting one end of the resistance heating section 7 and the drive circuit 6 is formed. A drive circuit terminal 6-1 for receiving a control signal from the outside to the drive circuit 6 is formed, and a common electrode 11 for connecting the other end of the resistance heating section 7 and the power supply terminal 9 is formed. Is formed.

The above-described resistance heating section 7 and individual drive electrodes 8
A plurality of orifices 4 are provided correspondingly. The partition 12 is laminated on these. Further, an ink supply groove 13 is formed on the surface of the chip substrate 5 in parallel with the nozzle row 3, and an ink supply hole 14 penetrating through the lower surface of the chip substrate 5 is formed so as to communicate with the ink supply groove 13. ing.

[0009] An orifice plate 15 is adhered and laminated on the upper layer of the partition 12 so that the height corresponding to the thickness of the partition 12 is about 10 μm.
m of the ink passage 16 is formed by the resistance heating portion 7 and the ink supply groove 1.
It is formed between three. In the orifice plate 15,
The above-mentioned orifice 4 for discharging ink is formed.

A full-color ink jet printer head 17 shown in FIG. 1D is formed by monolithically arranging four rows of the above-described print head 1 as a constituent element. As described above, it is possible to form the full-color ink-jet printer head 17 in a monolithic manner by arranging the structures of the mono-color ink-jet printer heads in four rows, and the positional relationship of each row can be changed according to today's semiconductor manufacturing. It is possible to place it accurately by technology.

The process up to this point is performed in the state of a silicon wafer. And finally, cutting along the scribe line using a dicing saw or the like, dividing into individual chip substrate units, die bonding to the mounting substrate,
The terminals are connected by wire bonding to complete a practical unit of a full-color inkjet printer head 17.

In the full-color ink jet printer head 17, during printing, ink is constantly supplied from an external ink cartridge or the like to the resistance heating section 7 through the ink supply holes 14 and the ink supply grooves 13, and printing from the drive circuit 6 is performed. Based on the application of the drive signal according to the data, each of the resistance heating sections 7 is selectively energized by the individual wiring electrode 8 and the common electrode 11 and instantaneously generates heat to cause a film boiling phenomenon at the interface with the ink. . An ink droplet is ejected from the orifice 4 corresponding to the resistance heating section 7 by the pressure of the film bubble generated by the film boiling phenomenon. The ejected ink droplets land on the opposing paper surface to form print dots, whereby an image is printed.

By the way, when the printing operation is repeated as described above, the ink droplets ejected from the orifice 4 bounce off the printing object such as paper, or the portions other than the main droplets of the ink droplets become mist. The ink droplets scatter and adhere to the surface of the orifice plate 15 as dirt, thereby causing a problem that ink droplet ejection becomes unstable.

FIG. 7 (a) is a diagram schematically showing the print head 1 of FIG. 6 (a) in a slightly enlarged manner, and FIG.
FIG. 2 is an enlarged cross-sectional view of the orifice, showing only the orifice 4 and its periphery. FIGS. 3C and 3D are diagrams for explaining the above-mentioned problems.

As shown in FIG. 1B, the ink 18 on the ink ejection surface of the orifice 4 of the print head 1, which is disposed in the vicinity of the paper surface (not shown) downward, is initially provided with a uniform meniscus. 18a is formed and printed (printed)
Occasionally, the ink droplets are ejected toward a sheet surface (not shown) as shown by an arrow C in FIG.

However, as shown in FIG. 3C, when the ink that has bounced back and the ink that has scattered in the form of mist adheres to the periphery of the orifice 4 as shown in FIG. Is ink stain 18
b and is pulled in the direction of the ink stain 18b as shown by the arrow D, and the shape of the meniscus 18a is deformed.

Due to the deformation of the meniscus 18a, the ejection direction of the ink droplet at the time of printing indicated by the arrow E becomes unstable, and the landing position of the ejected ink droplet on the paper surface is shifted, or A large number of fine ink droplets are ejected along with the ink droplets, and unnecessary fine dots called satellites are formed around the landing dots, causing a problem that the image quality is deteriorated.

In addition, even when the ink stain 18b does not adhere, if the periphery of the orifice 4 is hydrophilic,
As shown in (d), the meniscus 18a of the ink 18 is
It spreads over the surface of the orifice plate 15 around the orifice 4, and in this case, the above-described problem still occurs.

Therefore, in order to solve the above problem,
The periphery of the orifice 4 on the surface of the orifice plate 15 is formed in a water-repellent region to prevent the ink stain 18b from adhering.
As a destination for the blocked ink stain 18b, one in which a hydrophilic region is formed outside the water-repellent region has been put to practical use.

FIG. 8 (a) is a diagram schematically showing such a print head 1 ', and FIG. 8 (b) is an enlarged cross-sectional view taken along the line GG' of FIG. Print head 1 'shown in FIGS.
Comprises the orifice plate 15 of a water-repellent material,
A certain area outside the peripheral portion of the orifice 4 is selectively formed into a hydrophilic region by surface treatment or the like, or a sheet made of a hydrophilic material is adhered with an adhesive, and the peripheral portion of the orifice 4 is water-repellent. The region 19 and the hydrophilic region 21 outside the region 19 are formed.

As a result, as shown in FIG. 2B, the ink stain 18b adhering to the water-repellent area 19 around the orifice 4 is separated by the water-repellent property of the water-repellent area 19, and the hydrophilic property on the outside is removed. As a result, the ink 21 is adsorbed on the area 21 as indicated by the arrow H, and therefore, the problem that the ink stain 18b adversely affects the meniscus 18a of the orifice 4 as described above is eliminated.

[0022]

However, while the water repellency of one water repellent material is unlikely to change over time, the hydrophilicity of the other hydrophilic material is easily lost over time, and its life is extremely short. have. Further, in general, the contact angle of the hydrophilic region with the aqueous ink is not so small.

FIG. 9A is a diagram showing an example of the time-dependent characteristics of the contact angle of the hydrophilic region with the aqueous ink.
(c) is a diagram for explaining the contact angle of the aqueous ink. Same figure
(a) shows the number of prints on the horizontal axis, which can be replaced by time. The vertical axis indicates the contact angle of the aqueous ink.

As shown in FIG. 9A, in the hydrophilic region, the contact angle of the attached aqueous ink is small at the initial stage. For example, the contact angle α of the aqueous ink droplet 22 shown in FIG. The small, aqueous ink droplets 22 spread well and adhere to the hydrophilic regions 21. That is, the hydrophilicity of the hydrophilic region 21 is strong.

However, as time elapses, the contact angle increases as shown in FIG. That is, the contact angle β of the water-based ink droplet 22 'shown in FIG. That is, hydrophilicity deteriorates. Then, the state where the hydrophilicity is deteriorated is maintained.

As described above, the poor aging characteristics of the hydrophilic member, that is, the fact that the hydrophilicity of the hydrophilic region outside the vicinity of the orifice with respect to the aqueous ink is liable to deteriorate with time, means that a long-life ink jet printer head is required. This is one of the obstacles in the design when trying to configure, and therefore, there is a problem that the degree of freedom is restricted in the design of the ink jet printer head.

The object of the present invention is to solve the above-mentioned conventional situation,
An object of the present invention is to provide a method of manufacturing an ink jet printer head capable of permanently maintaining the hydrophilicity of a hydrophilic region required for an orifice plate, and an ink jet printing apparatus provided with the ink jet printer head.

[0028]

According to a first aspect of the present invention, there is provided a method of manufacturing an ink jet print head, comprising: a plurality of ink jet print heads arranged in a predetermined direction on a substrate for generating pressure energy for discharging a liquid; An energy generating element, a partition wall that is formed on the substrate, and defines a pressurized chamber that applies pressure to the liquid by each of the energy generating elements, and an orifice for ink ejection provided to overlap with the partition wall. Ink jet printing having an orifice plate formed, and an ink flow path for supplying ink to the pressurizing chamber, and discharging the liquid in a predetermined direction by driving the energy generating element to perform recording on a recording medium. In the method for manufacturing a head, the step of forming the orifice includes: a step of sputtering a Ti thin film on the orifice plate; Includes a step of patterning by photolithography E. the Ti thin film formed by degree, and a step of performing a helicon O ₂ plasma etching according to the pattern formed by the process, the Ti film by the helicon O ₂ plasma etching Is changed to a Ti oxide film.

Then, the method further comprises a step of removing the Ti oxide film around the orifice. Further, for example, the method further includes a step of performing a water-repellent treatment on the surface of the Ti oxide film around the orifice.

Next, an ink-jet printing apparatus according to a fourth aspect of the present invention is directed to an ink-jet printing apparatus comprising: a plurality of energy generating elements arranged in a predetermined direction on a substrate for generating pressure energy for discharging a liquid; An orifice plate which is formed on the partition wall to form a pressurized chamber for applying pressure to the liquid by each of the energy generating elements, an orifice plate provided on the partition wall and having an orifice for discharging ink, and An ink jet printing apparatus including an ink jet print head having the Ti oxide film formed on a surface of a plate and an ink flow path for supplying ink to the pressurizing chamber, wherein an ultraviolet ray is applied to the Ti oxide film. Is provided with ultraviolet irradiation means for irradiating light.

In addition, for example, as set forth in claim 5, a driving means for driving the ultraviolet irradiation means is provided every predetermined time or every time predetermined printing is performed.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are cross-sectional views schematically showing the configuration of an orifice of an ink jet printer head and its vicinity in an embodiment of the present invention. FIG. 3A shows the partition 23 and the orifice plate 2.
4, orifice 25, ink 26, meniscus 26a,
A water-repellent region 27 and a hydrophilic region 28 are shown. FIG. 2B shows the partition 23, the orifice plate 24, the orifice 25, the ink 26, and the meniscus 2 in the same manner as described above.
6a, the water-repellent region 27, and the hydrophilic region 28 are shown, but the configuration of the water-repellent region 27 is different from FIG.

First, FIG. 2A shows the orifice plate 2.
4 Orifice 25 of hydrophilic membrane member covered on the surface
The peripheral hydrophilic film member is removed to expose the surface of the orifice plate 24 serving as a base, the exposed portion is defined as a water-repellent region 27, and the remaining hydrophilic film member is defined as a hydrophilic region 28. 1 shows an inkjet printer head 30. In this case, a polyimide film is used for the orifice plate 24. Polyimide itself has very good water repellency.

FIG. 4B shows a state in which the hydrophilic film member covered as described above is left as it is on the surface of the orifice plate 24, and is repelled by being superposed on the hydrophilic film member around the orifice 25. An ink jet printer head 30 'in which a water-repellent region 27 is formed by coating a water-based member is shown.

FIGS. 2 (a), (b), (c), (d), and (e) show a method of manufacturing the ink jet printer head of the present invention configured as described above. In general, when an ink jet printer head is used, the ink jet printer head is shown in FIG.
As shown in FIG. 2 (b), the ink ejection surface is used with the ink ejection surface facing downward, but during the manufacturing process, as shown in FIGS. 2 (a) to 2 (e), the processing is performed with the ink ejection surface facing upward. It is processed.

FIG. 2A shows a head chip 29, a resistance heating portion 31 formed on the head chip 29, and three sides of the resistance heating portion 31 (the sectional views in FIGS. 2A to 2E). Therefore, only two sides are shown.) The partition 23 and the orifice plate 24 shown in FIGS. 1A and 1B are shown. A Ti (titanium) film 32 is provided on the surface of the orifice plate 24.
Is covered.

The Ti film 32 is a mask material for selectively etching the orifice plate 24 to form the orifice 25 and the terminal connection holes, but this mask material is usually made of Al, Cu or Ta. Use relatively inexpensive metals. However, in the ink jet printer head of the present invention, Ti is used for the mask material. As shown in FIG. 2A, a Ti film 32 having a thickness of about 0.5 to 1 μm is formed on the orifice plate 24 by sputtering or vapor deposition using this Ti.

An opening corresponding to the orifice 25 shown in FIGS. 1A and 1B is formed in the Ti film 32 by using a photolithography technique and an appropriate etching technique. As a result, as shown in FIG.
Is formed on the surface of the mask pattern 32-1.

Usually, the selectivity of the polyimide film, that is, the orifice plate 24 and the metal film mask is approximately 50 to 50.
About 100 can be obtained. Therefore, the etching of the orifice plate 24 having a thickness of about 30 μm is sufficiently possible even with a metal film mask having a thickness of 1 μm or less.

In order to etch the orifice plate 24 in accordance with the mask pattern 32-1 to form the orifice 25, high-density plasma can be generated and high-speed processing can be performed. Helicon wave etching equipment, which is currently considered to be the most efficient, is used.

First, a head chip 29, ie, a silicon wafer on which a large number of head chips 29 are formed, is loaded into a process chamber (processing chamber) of a helicon wave etching apparatus (not shown), and this silicon wafer is loaded into the process chamber. It is fixed on a wafer fixing stage projecting from the center. Then, holes are formed in the orifice 25 by dry etching.

Various gases are used as the process gas for the dry etching by the helicon wave etching apparatus. In the present invention, oxygen (O ₂ ) is used. In the helicon wave etching apparatus, the processing oxygen O ₂ becomes an oxygen plasma 33 as shown in FIG. 2C, and is divided into two components of oxygen ions and oxygen radical atoms, and the Ti film 32 (32-1) ) Is sprayed on the surface.

As a result, the orifice plate 24 under the Ti thin film 32 remains without being scraped, and the portion without the Ti film 32, that is, the orifice plate 24 at the opening of the mask pattern 32-1 is selectively scraped and penetrated. , Orifice 25 is formed.

At this time, the non-opening portion of the mask pattern 32-1, that is, the Ti film 32 itself is also shaved by about 0.5 μm.
Then, the remaining surface is oxidized to oxidize T
An i-film 32-2 is formed.

Ti oxide has a very high degree of hydrophilicity as its physical properties. Therefore, when the Ti film is used as a mask for forming an orifice hole and oxygen (O ₂ ) is used as a processing gas of the helicon wave etching apparatus as described above, the Ti oxide film 32-
2 can be formed on the upper surface of the orifice plate 24 to be a hydrophilic region. Therefore, there is no need to form a hydrophilic region in a separate step as in the related art.

Thereafter, as shown in FIG. 2D, the hydrophilic Ti oxide film 3 formed on the surface of the orifice plate 24 is formed.
The peripheral portion of the orifice 25 in 2-2 is removed to expose the surface of the orifice plate 24 serving as a base, the exposed portion is used as a water-repellent region 27, and the remaining portion of the Ti oxide film 32-2 is removed. An ink jet printer head 30 shown in FIG.

Alternatively, as shown in FIG. 2E, the hydrophilic region 28 is formed while leaving the Ti oxide film 32-2 on the surface of the orifice plate 24 as it is, and the Ti oxide film 32-2 around the orifice 25 is formed. A water-repellent member 34 is coated thereon to form a water-repellent region 27, thereby forming an ink jet printer head 30 'shown in FIG. 1 (b).

Incidentally, titanium oxide (Ti oxide film 32-
2) is extremely strong hydrophilicity (super hydrophilicity) as described above.
The superhydrophilicity is obtained by a photocatalytic action caused by irradiating the surface of titanium oxide with ultraviolet rays. The superhydrophilicity of this titanium oxide deteriorates with time, similarly to the hydrophilicity of other hydrophilic substances.
However, in the case of titanium oxide, the superhydrophilicity is regenerated, that is, restored, by irradiating with ultraviolet rays.

The superhydrophilicity of the titanium oxide, which is regenerated by the photocatalytic action, is excellent in stability over time, and the superhydrophilicity can be repeatedly maintained by regularly irradiating ultraviolet rays. In the present invention, in addition to the above-described manufacturing method, the inkjet printer head 30 or 30 ′ is utilized by utilizing the superhydrophilicity of the titanium oxide by photocatalysis.
In addition, the permanent hydrophilicity of the hydrophilic region 28, which is also super-hydrophilic, is maintained. This will be described below.

FIG. 3 (a) is a view schematically showing the structure of a main part of an ink jet printing apparatus for maintaining the hydrophilicity (super hydrophilicity, the same applies hereinafter) of the ink jet printer head of the present invention permanently. FIG. 2B is a diagram specifically showing a state where the hydrophilicity is permanently maintained. In FIG. 5B, the horizontal axis indicates the number of times of printing, and the vertical axis indicates the contact angle of the water-soluble ink droplet adhering to the hydrophilic region.

In the main part of the ink jet printing apparatus shown in FIG.
(Or 30 ', hereinafter the same) can be moved to a print area outside the right side of the drawing and a non-printing position shown in the figure, as indicated by an arrow J in the figure. In this non-printing position, an ultraviolet lamp 35 is provided at a position facing the hydrophilic region made of the above-described Ti oxide film 32-2 on the ink ejection surface of the orifice plate of the inkjet printer head 30.

In this ink jet printing apparatus,
When the power is turned on, when the number of printings reaches a certain number of times, or when the non-printing time reaches a certain time, the inkjet printer head 30 moves to the non-printing position shown in FIG. Then, the ultraviolet lamp 35 is driven to emit light for a predetermined time, so that the ink ejection surface of the orifice plate of the ink jet printer head 30 is irradiated with ultraviolet light.

As a result, as shown in FIG. 4B, the hydrophilicity of the hydrophilic region of Ti oxide, which has been deteriorated by a change with time, can be restored by the photocatalytic action. That is, FIG.
As can be seen, the contact angle of the hydrophilic ink droplet, which has changed to a large angle due to the weakened hydrophilicity, returns to the initial small contact angle again because the hydrophilicity of the hydrophilic region has been restored by photocatalysis. Are repeated with the number of times of printing (elapse of time).

FIG. 4 is a flow chart for explaining the control processing operation of ultraviolet irradiation on the ink ejection surface of the ink jet printer head 30 when the power is turned on, when a predetermined number of printings is completed, or when a predetermined time has elapsed. This processing operation is performed under the control of a control unit (not shown) of the ink jet printing apparatus. In addition, the control unit uses a built-in timer for this processing, sets a register N area in a RAM area (not shown), and further performs processing using a preset print limit parameter K.

In the figure, when the power is first turned on to the ink jet printing apparatus (step S1), as shown in FIG. 3A, the ink jet printer head 30 moves to the non-printing position, and the ultraviolet lamp 35 is turned on. After being driven to emit light for a predetermined time, the ink ejection surface of the orifice plate of the ink jet printer head 30 is irradiated with ultraviolet rays (step S2). Thus, when the power of the ink jet printing apparatus is turned on, ultraviolet irradiation is always performed first, and the hydrophilicity of the hydrophilic area formed around the outer periphery of the ink jet printer head 30 near the orifice is restored.

Following the above, the register N is cleared to "0" (step S3). Thus, the register N is ready to count the number of times of printing from the first sheet. Next, the timer is reset (step S4). Thus, measurement of the elapsed time after the irradiation of the ultraviolet rays is started.

Next, it is determined whether or not the timer has expired (step S5). In this process, immediately after turning on the power to the inkjet printing apparatus, the timer has not yet timed out, so the determination is “NO”. In this case, it is subsequently determined whether or not one printing has been performed. It is determined (step S6).

If one printing has not been completed yet (S6: NO), the process returns to step S5 is repeated until one printing is completed. As a result, both the elapsed time after ultraviolet irradiation and the number of printings are monitored in parallel.

When one printing is completed, (S
6 is YES), the register N is incremented by "1" (step S7). Thus, each time printing is completed once, the number of times of printing is counted (cumulative).

Subsequently, it is determined whether or not the count value of the register N has reached a predetermined print limit number K (step S8). If the maximum number of prints K has not been reached (S8: NO), the process returns to step S5 and repeats steps S5 to S8. Step S8
If the value of the register N has reached the maximum number of prints K (YES in S8), the flow returns to step S2 to perform the above-described ultraviolet irradiation processing, and then repeats the steps from step S2.

Thus, when the number of printed sheets reaches the predetermined limit number, the deteriorated hydrophilicity of the hydrophilic region composed of the Ti oxide film is restored to the original state by the ultraviolet irradiation treatment, and the number of printed sheets and the elapsed time are restored again. Is measured from the beginning, and the printing process is executed.

When it is determined in step S5 that the time is up, it means that a predetermined elapsed time has elapsed after the irradiation of the ultraviolet rays. In this case, the process returns to step S2 to perform the irradiation of the ultraviolet rays.

Thus, for example, when the printing time interval is long and the number of printings does not reach the predetermined printing limit number indicating the number of sheets whose water repellency drops below the limit when the printing is performed at the normal printing time interval. However, based on the elapsed time during which the water repellency falls below the limit, a process of restoring the hydrophilicity of the hydrophilic region due to the irradiation of ultraviolet rays is performed.

In the above-described embodiment, the ultraviolet discharge lamp is used to irradiate the increment discharge surface of the ink jet printer head, that is, the hydrophilic region made of the Ti oxide film, with the ultraviolet light. The ultraviolet irradiation is not limited to this, and natural light from a window of a room where the inkjet printing apparatus is installed may be used. In addition, since it is considered that there is a lighting device in most environments where the ink jet printing apparatus is used, ultraviolet light in light emitted from the lighting device may be used. In any case, the hydrophilicity of the Ti oxide film can be restored and maintained.

However, the ink jet printer head 30
Is provided with the ink ejection surface facing down inside the main body housing of the ink jet printing apparatus, so that natural light or room light can be effectively irradiated to the ink ejection surface of the ink jet printer head 30 as it is. Can not.

FIG. 5 shows another example of the configuration of the main part of an ink jet printing apparatus which effectively irradiates natural light or room light to the ink ejection surface of the ink jet printer head to maintain the hydrophilicity of the ink jet printer head permanently. It is a figure which shows typically.

As shown in the figure, an ink jet printing device 36 is provided inside a main body casing 37 with, for example, an optical fiber or a combination which reaches the lower surface of the ink jet printer head 30 when it is at an internal non-printing position. A light guide path 38 including a reflecting mirror and the like is provided. External light 39 is taken in through the light guide path 38 and becomes irradiation light 39-1 which is irradiated on the titanium oxide film 32-2 on the lower surface of the ink jet printer head 30. Even if configured in this way,
By the control shown in FIG. 4, permanent maintenance of hydrophilicity can be realized as in the case of FIG. 3 (a).

In the above-described embodiment, the description has been made using the thermal type ink jet printer head and its ink jet printing apparatus. However, the present invention is not limited to this. Of course, it can be applied.

[0069]

As described above in detail, according to the present invention, the mask pattern film for forming orifice holes on the surface of the orifice plate of the ink jet print head is made of Ti.
Since O ₂ is used as a processing gas for helicon wave etching for forming an orifice hole and forming an orifice hole, a highly hydrophilic Ti oxide film can be formed on the surface of the orifice plate. By utilizing this, a necessary hydrophilic region can be formed outside and around the orifice without going through a special process.

Further, an ultraviolet irradiation unit by an ultraviolet irradiation lamp or a natural light (including room light) irradiation unit by a light guide path from the outside is provided within a movable range of the printer ink jet printer head of the ink jet printing device. When the power is turned on, when the number of printings reaches a certain number of times, or when the non-printing time reaches a certain time, etc., the ink ejection surface of the orifice plate is irradiated with ultraviolet light or natural light. ,
The hydrophilic property of Ti oxide, which has been deteriorated due to the change with time, can be restored by photocatalysis, whereby the super-hydrophilic property of Ti oxide can be maintained semipermanently.

[Brief description of the drawings]

FIGS. 1A and 1B are cross-sectional views schematically showing the configuration of an orifice of an ink jet printer head and its vicinity in an embodiment of the present invention.

FIGS. 2 (a), (b), (c), (d), and (e) are diagrams illustrating a method of manufacturing an ink jet printer head according to the present invention.

FIG. 3A is a diagram schematically showing the configuration of a main part of an ink jet printing apparatus for maintaining the hydrophilicity of the ink jet printer head of the present invention permanently, and FIG. It is a figure which shows the state performed specifically.

FIG. 4 is a flowchart illustrating a processing operation for maintaining hydrophilicity of the inkjet printing apparatus of the present invention.

FIG. 5 is a diagram schematically showing another configuration example of a main part of an ink jet printing apparatus for maintaining the hydrophilicity of the ink jet printer head of the present invention permanently.

6A is a plan view schematically showing an ink ejection surface of a conventional mono-color ink jet printer head, FIG. 6B is an enlarged cross-sectional view taken along the line AA 'of FIG. 6, and FIG. (D) is a diagram showing a full-color ink jet printer head provided with four nozzle rows.

7A is an enlarged schematic view of a conventional mono-color ink jet printer head, and FIG.
(B) and (d) are diagrams for explaining the problem.

FIG. 8A is a view schematically showing a conventional improved type ink jet printer head, and FIG. 8B is an enlarged view of the section taken along the line GG ′ of FIG.

9A is a diagram illustrating an example of a temporal characteristic of a contact angle of a hydrophilic region with an aqueous ink, and FIGS. 9B and 9C are diagrams illustrating a contact angle of the aqueous ink.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 1 'Mono-color ink jet printer head (print head) 2 Silicon wafer 3 Nozzle row 4 Orifice 5 Head chip 6 Drive circuit 7 Resistance heating part 8 Individual wiring electrode 9 Power supply terminal 11 Common electrode 12 Partition wall 13 Ink supply groove 14 Ink Supply hole 15 Orifice plate 16 Ink passage 17 Full-color inkjet printer head 18 Ink 18a Meniscus 18b Ink stain 19 Water-repellent area 21 Hydrophilic area 22, 22 'Water-based ink drop 23 Partition wall 24 Orifice plate 25 Orifice 26 Ink 26a Meniscus 27 Water-repellent area 28 Hydrophilic area 29 Head chip 30, 30 'Inkjet printer head 31 Resistance heating part 32 Ti (titanium) film 32-1 Mask pattern 32-2 Ti oxide film 33 Acid Plasma 34 repellent member 35 UV lamp 36 inkjet printer 37 main housing

Claims (5)

[Claims] A plurality of energy generating elements arranged in a predetermined direction on a substrate to generate pressure energy for discharging a liquid; and a plurality of energy generating elements erected on the substrate and formed by the energy generating elements. A partition for forming a pressurized chamber for applying pressure to the partition, an orifice plate provided with an orifice for ink ejection provided to overlap the partition, and an ink flow path for supplying ink to the pressurized chamber, A method of manufacturing an ink jet print head that discharges the liquid in a predetermined direction by driving the energy generating element to perform recording on a recording medium, wherein the step of forming the orifice includes: A step of sputtering a thin film; and a step of patterning the Ti thin film formed by the step by photolithography. Helicon O ₂ according to the pattern formed by the process.
A method of performing plasma etching, wherein the Ti thin film is changed to a Ti oxide film by the helicon O ₂ plasma etching. 2. The method according to claim 1, further comprising removing the Ti oxide film around the orifice.
A manufacturing method of the ink jet printer head described in the above. 3. The method for manufacturing an ink jet printer head according to claim 1, further comprising a step of performing a water-repellent treatment on a surface of said Ti oxide film around said orifice. 4. A plurality of energy generating elements arranged in a predetermined direction on a substrate to generate pressure energy for discharging a liquid, and a plurality of energy generating elements erected on the substrate to form the liquid by the energy generating elements. A partition wall for forming a pressurizing chamber for applying pressure, an orifice plate provided with an orifice for ink ejection provided so as to overlap with the partition wall, and the Ti oxide film formed on the surface of the orifice plate; An ink jet printing apparatus including an ink jet print head having an ink flow path for supplying ink to the pressurizing chamber, comprising: an ultraviolet light irradiating unit configured to irradiate the Ti oxide film with ultraviolet light. Inkjet printing device. 5. The ink jet printing apparatus according to claim 4, further comprising a driving unit for driving said ultraviolet irradiation unit every predetermined time or every time predetermined printing is performed.