JP4146933B2 - Ink jet head and method of manufacturing ink jet head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inkjet head that forms an image by ejecting ink, and more specifically, adhesion between a substrate on which an ink ejection pressure generating element is formed and a fluid path forming member that forms a fluid path by joining the substrate. Regarding improvement.
[0002]
[Prior art]
Conventionally, various proposals have been made for a liquid path forming member that forms a liquid path by joining with a method for manufacturing an ink jet head and a substrate on which an ink discharge pressure generating element is formed. For example, Japanese Patent Laid-Open No. 57-208255. 56, a method of forming an ink jet head by forming a liquid path pattern with a photosensitive resin on a substrate on which an ink discharge pressure generating element is formed, and joining and cutting a top plate such as glass. Disclosure.
[0003]
In Hewlett Packard Journal 36, 5 (1985), a liquid path pattern is formed with a photosensitive resin on a substrate on which an ink discharge pressure generating element is formed, and an orifice plate formed by Ni electroforming is bonded to the substrate. A method of making an inkjet head is disclosed.
[0004]
Japanese Patent Application Laid-Open No. 61-154947 discloses that a liquid path pattern is formed of a soluble resin on an ink discharge pressure generating element of a substrate on which an ink discharge pressure generating element is formed. A method is disclosed in which an ink jet head is prepared by elution of a resin layer that is coated and cured with, for example, and is dissolved after cutting the substrate.
[0005]
Further, in JP-A-3-184868, a cationic polymerization cured product of an aromatic epoxy compound is useful as a coating resin composition optimal for the production of the ink jet head described in JP-A-61-154947. It is disclosed.
[0006]
In any of the above methods, the bonding between the substrate on which the ink discharge pressure generating element is formed and the liquid path forming member basically depends on the adhesion force of the resin (photosensitive resin layer, covering resin layer) that becomes the liquid path forming member. is doing.
[0007]
[Problems to be solved by the invention]
By the way, in the case of a so-called bubble jet head that uses a heating resistor as an ink discharge pressure generating element and forms a bubble by ink film boiling and discharges the ink, damage caused by erosion caused by ink and bubble cavitation is reduced. For this purpose, an inorganic insulating layer such as SiN or SiO ₂ and an anti-cavitation layer such as Ta are generally provided on the heating resistor. Here, since the adhesion of the Ta film to the resin as the liquid path forming member is extremely low, peeling of the liquid path forming member from the Ta film may be observed.
[0008]
Here, in order to improve the adhesion of the liquid path forming member, it may be possible to remove the Ta film where the liquid path forming member is provided. In this case, the electrothermal transducer on the substrate is the inorganic insulating layer described above. The resin constituting the liquid path forming member is laminated only through the above. However, the inorganic insulating layer usually has a porous film quality, and permeates ions contained in the resin, which may corrode the electrothermal transducer.
[0009]
Further, in order to improve the adhesion between the substrate on which the ink discharge pressure generating element is formed and the liquid passage forming member, the substrate is subjected to silane coupling treatment or made of polyimide (for example, Photo Nice manufactured by Toray Industries, Inc.). An example using a lower layer (adhesion enhancement and passivation layer) is known.
[0010]
Here, since the inkjet head is normally in contact with the ink in accordance with the usage environment, the substrate on which the ink discharge pressure generating element is formed and the liquid path forming member are peeled off due to the influence of the ink. That must be avoided. In recent years, demands for paper selectivity, water resistance, and the like have been increasing for inkjet recording, and in order to meet these demands, it has been studied to make the ink weakly alkaline. For such weakly alkaline ink, it may be difficult to maintain the adhesion between the substrate on which the ink discharge pressure generating element is formed and the liquid path forming member for a long period of time.
[0011]
The present invention has been made in view of the above-described points, and provides a highly reliable ink jet head by increasing the adhesion between a substrate on which an ink discharge pressure generating element is formed and a liquid path forming member.
[0012]
[Means for Solving the Problems]
A substrate provided with a pressure generating element that is included in a liquid passage communicating with an ejection port for ejecting ink and generates pressure used to eject ink from the ejection port, and bonded to the substrate An ink jet head capable of discharging alkaline ink, wherein the substrate has an inorganic material layer made of Ta, SiO ₂ or SiN on the surface. The liquid path forming member is made of a cured resin and is bonded to the inorganic material layer through an adhesion layer made of a polyetheramide resin.
[0013]
Furthermore, the present invention provides a substrate provided with a pressure generating element that is included in a liquid passage communicating with an ejection port for ejecting ink and generates pressure used to eject ink from the ejection port, and the substrate A liquid path forming member that forms the liquid path by being joined to the ink jet head, and is a method of manufacturing an inkjet head capable of discharging alkaline ink, the surface of which is made of any one of Ta, SiO _2, and SiN Forming an adhesion layer made of a polyetheramide resin on the inorganic material layer of the substrate on which the inorganic material layer is formed; and forming a pattern of the liquid path on the substrate with a soluble resin. And a step of forming a coating resin layer for forming the liquid path forming member on the adhesion layer and the pattern, and a position of the coating resin layer above the pressure generating element, An ink jet head manufacturing method comprising: forming the discharge port; and eluting the pattern to form the liquid path.
[0014]
According to the above configuration, excellent adhesion can be maintained for a long time even with alkaline ink, and excellent even for a long time even when a metal surface such as Ta is exposed on the adhesive surface. It is possible to provide a highly reliable inkjet head capable of maintaining the adhesion.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to examples.
[0016]
(Example 1)
In this example, polyether amide was disposed between the substrate and the material constituting the nozzle, and the adhesion to weak alkaline ink was evaluated by an acceleration test.
[0017]
First, a 5-inch Si wafer was prepared as a substrate, and a 1.0 μm SiO ₂ layer was formed by thermal oxidation. Next, a polyether amide resin (HIMAL 1200 [solvent N-methylpyrrolidone / butyl cellosolve acetate] manufactured by Hitachi Chemical Co., Ltd.) was formed by spin coating as an adhesion layer, and 100 ° C./30 minutes + 250 ° C./1. The coating solvent was evaporated by heating for a period of time to form a film having a thickness of 1.5 μm.
[0018]
Here, the adhesion layer made of the polyether amide is thermoplastic, and heating is performed for the purpose of evaporating the solvent and reducing the internal stress to a glass transition point (230 ° C.) or higher.
[0019]
Next, Liston (trade name: manufactured by DuPont), which is a dry film resist, was laminated as a nozzle constituent material on the substrate, and patterning was performed using a mask aligner PLA600 to form a 30 μm line & space (L & S) pattern. (Film thickness 20μm)
[0020]
Next, the pattern was completely cured by heating at 150 ° C. for 1 hour.
At the same time, as a comparative example, a sample using no adhesion layer and a sample using polyimide (Photo Nice UR3100 400 ° C. bake, film thickness 1.5 μm, manufactured by Toray Industries, Inc.) as the adhesion layer were prepared.
[0021]
Next, these samples were immersed in an ink composed of ethylene glycol / urea / isopropyl alcohol / black dye / water = 5/3/2/3/87 parts, and a pressure cooker (PCT) test (120 ° C., 2 atm. 50 Hr) was performed. The change in the L & S pattern was observed.
[0022]
Here, urea is added to the ink as a moisturizing component (which reduces ink evaporation and prevents nozzle clogging), and exhibits weak alkalinity due to hydrolysis of urea.
[0023]
Regarding the sample provided with the polyetheramide adhesion layer according to the present invention, no change in the pattern shape was observed even after the PCT test. On the other hand, interference fringes and peeling were confirmed in some patterns of the samples not using the adhesion layer. This is considered to be caused by insufficient adhesion between the SiO ₂ layer and the nozzle constituent material. Moreover, the polyimide layer melt | dissolved and disappeared about the sample which used the polyimide as an adhesion layer.
[0024]
From this result, it is understood that the polyetheramide adhesion layer which is a constitution of the present invention exhibits excellent adhesion and ink resistance.
[0025]
(Example 2)
Next, an example in which an epoxy resin is used as a nozzle member and a substrate having a SiN + Ta film structure on the substrate surface will be described.
[0026]
A 5-inch Si wafer was prepared as a substrate, a SiN film was formed to 1.0 μm by plasma CVD, and a Ta film was further formed to 0.25 μm thereon.
[0027]
Next, a polyetheramide film was formed in the same manner as in Example 1, and an epoxy resin composition having the following composition as a nozzle constituent member was appropriately dissolved in a coating solvent and coated on the polyetheramide film for patterning.
・ Epoxy resin EHPE (trade name: manufactured by Daicel Chemical Industries, Ltd.) 100 parts by weight additive resin 1.4-HFAB (trade name: manufactured by Central Glass Co., Ltd.) 20 parts by weight silane coupling agent A-187 (trade name: manufactured by Nihon Unicar) 5 parts by weight photocationic polymerization catalyst SP170 (trade name: manufactured by Asahi Denka Kogyo Co., Ltd.) 2 parts by weight [0028]
Here, the composition is a composition capable of cationic polymerization of an epoxy resin, and cationic polymerization is initiated and patterned by light irradiation.
[0029]
Patterning was performed using a Canon mask aligner MPA600 at an exposure amount of −3.0 J / cm ^2. After exposure, the film was heated on a hot plate at 90 ° C. for 30 minutes, and then developed with a methyl isobutyl ketone / xylene mixed solvent. Further, after the development, the film was heated at 180 ° C./1 hour to perform main curing.
In this manner, a 30 μmL & S pattern having a film thickness of 20 μm was formed in the same manner as in Example 1. Next, PCT was performed in the same manner as in Example 1 to observe changes in the L & S pattern.
[0030]
Also in this example, no change in the shape of the pattern was observed after the PCT test for the sample provided with the polyetheramide adhesion layer having the structure of the present invention. On the other hand, interference fringes and peeling were confirmed in some patterns of the samples not using the adhesion layer. This is considered to be caused by insufficient adhesion between the Ta layer and the nozzle constituent material.
[0031]
Thus, it can be understood from the above results that the polyetheramide film exhibits excellent adhesion.
[0032]
(Example 3)
In this example, the adhesion strength in the form of an inkjet head was evaluated.
[0033]
First, an ink jet head was prepared by the following method.
[0034]
As shown in FIG. 1, an electrothermal conversion element (TaN) 2 is arranged as an ink pressure generating element on a Si wafer substrate 1 having a crystal axis <100> provided with an ink supply port mask 3, and a SiN layer 4 as a protective layer. A Ta layer 5 was formed. The electrothermal conversion element 2 is connected to a control signal input electrode for operating the element (not shown). The AA 'cross section of FIG. 2, FIG. 1 is shown.
[0035]
Next, a layer 6 made of polyetheramide as an adhesion layer was formed on the substrate 1 with a thickness of 2.0 μm by the following method. For the polyetheramide layer, HIMAL1200 manufactured by Hitachi Chemical Co., Ltd. was used and applied onto the substrate 1 with a spinner and baked at 100 ° C./30 minutes + 250 ° C./1 hour.
[0036]
Next, patterning is performed on the HIMAL using a positive resist OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd., the HIMAL layer is patterned by O ₂ plasma ashing using the OFPR pattern as a mask, and finally the OFPR pattern used as the mask is formed. By peeling, an adhesion layer shown in FIG. 3 was formed.
[0037]
Next, as shown in FIG. 4, an ink flow path pattern made of Tokyo Ohka Kogyo Co., Ltd. positive resist ODUR was formed on the substrate 1 (thickness 12 μm: see FIG. 4).
[0038]
Furthermore, the epoxy resin layer 8 described in Example 2 was formed on the substrate 1, and the discharge port 9 was formed by patterning (see FIG. 5).
[0039]
Next, the substrate 1 was etched by Si anisotropic etching to form an ink supply port 10 (see FIG. 6).
[0040]
Next, the ink flow path pattern 7 was removed from the SiN film on the ink supply port and the ODUR, and further, heating was performed at 180 ° C./1 hour in order to completely cure the epoxy resin 8 as a nozzle constituent member, thereby obtaining an ink jet head. (See FIG. 7).
[0041]
Here, in the inkjet head, the nozzle constituent member 8 is bonded to the surface of the substrate 1 (Ta surface / SiN surface) via the adhesion layer 6.
[0042]
As a comparative example, an ink jet head having no adhesion layer 6 was also produced as a prototype. Here, in the inkjet head of the comparative example, the nozzle component 8 is bonded to the surface of the substrate 1 (Ta surface / SiN surface).
[0043]
When these ink jet heads were filled with the ink described in Example 1 and subjected to a storage test at 60 ° C. for 3 months, in the ink jet head of the above example (with an adhesive layer), the contact surface of the nozzle constituent member was No changes such as interference fringes or peeling were observed.
[0044]
On the other hand, in the comparative example (without the adhesion layer), a portion where a buffer stripe was generated between Ta and the nozzle constituting member was observed.
[0045]
As described above, it is understood that the polyetheramide adhesion layer exhibits an excellent effect even when formed as an actual ink jet head.
[0046]
【The invention's effect】
As described above, according to the present invention, by using polyetheramide as the adhesion layer, it is possible to maintain an excellent adhesion force for a long period of time even with respect to an alkaline ink. Even when a metal surface such as the above is exposed, it is possible to maintain excellent adhesion for a long period of time, and a highly reliable inkjet head can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view of an inkjet substrate.
FIG. 2 is an explanatory view showing a method for producing an ink jet head of the present invention.
FIG. 3 is an explanatory view showing a method for producing an ink jet head of the present invention.
FIG. 4 is an explanatory view showing a method for manufacturing an ink jet head of the present invention.
FIG. 5 is an explanatory view showing a method for manufacturing an ink jet head of the present invention.
FIG. 6 is an explanatory view showing a method for manufacturing an ink jet head of the present invention.
FIG. 7 is an explanatory view showing a method of manufacturing an ink jet head of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Si substrate 2 Ink discharge pressure generating element 3 Ink supply port mask 4 SiN film 5 Ta film 6 Adhesion layer 7 Liquid path pattern 8 Nozzle component 9 Discharge port 10 Ink supply port

Claims (8)

A substrate having a pressure generating element for generating pressure used to be contained in the liquid path communicating with the discharge port for discharging ink from the discharge ports for discharging ink, is provided,
A liquid path forming member that forms the liquid path by being bonded to the substrate;
Available to, an ink jet head capable of discharging an alkaline ink,
The substrate has an inorganic material layer made of any of Ta, SiO ₂ and SiN on the surface ,
The ink jet head according to claim 1, wherein the liquid path forming member is made of a cured resin and is bonded to the inorganic material layer through an adhesion layer made of a polyetheramide resin . The inkjet head according to claim 1, wherein the cured product of the resin is a cured product of an epoxy resin. The inkjet head according to claim 1, wherein the discharge port is formed at a position facing the pressure generating element. The inkjet head according to claim 1, wherein the pressure generating element is an electrothermal transducer. A substrate provided with a pressure generating element that is included in a liquid path communicating with an ejection port for ejecting ink and generates pressure used to eject ink from the ejection port;
A liquid path forming member that forms the liquid path by being bonded to the substrate;
An inkjet head manufacturing method capable of discharging alkaline ink,
Ta, SiO on the surface ₂ Forming an adhesion layer made of a polyetheramide resin on the inorganic material layer of the substrate on which an inorganic material layer made of any of SiN and SiN is formed;
Forming a pattern of the liquid path on the substrate with a soluble resin;
Forming a coating resin layer for forming the liquid path forming member on the adhesion layer and the pattern;
Forming the discharge port at a position above the pressure generating element of the coating resin layer;
Eluting the pattern to form the liquid path;
A method of manufacturing an ink jet head, comprising: 6. The method of manufacturing an ink jet head according to claim 5, wherein the coating resin layer contains an epoxy resin. 7. The method of manufacturing an ink jet head according to claim 5, wherein in the step of forming the adhesion layer, the polyetheramide resin is patterned by oxygen plasma ashing. The method of manufacturing an ink jet head according to claim 5, wherein the pressure generating element is an electrothermal transducer.

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