JPH09226135A - Ink jet printing head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a gap in the bonded part of a substrate and a top plate by bonding the substrate forming the bottom parts of a plurality of ink passages and the top plate forming the ceiling parts of a plurality of the ink passages by normal temp. bonding by surface activation. SOLUTION: A heater board 100 having ink emitting pressure generating elements and forming the bottom parts of a plurality of ink passages and a top plate 1300 forming the ceiling parts of a plurality of the ink passages are arranged on a bonding apparatus constituted of two vacuum chambers of a preparatory chamber and a pressure bonding chamber. In the pressure bonding chamber, the bonded part of the Si surface of the heater board 100 and the top plate 1300 having an Al membrane formed thereto is irradiated with energy particles by a saddle field type high speed atomic beam source. After the surfaces of the heater board and the top plate are activated by this irradiation, the Si exposed part 6 of the heater board 100 and the bonding part 1306 of the top plate 1300 are bonded. By this constitution, the gap between the top plate and the heater board is perfectly eliminated and the generation of a cross talk phenomenon can be prevented.

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 print head, and more particularly to a method for joining a substrate having an ink ejection pressure generating element and an ink jet head constituent member on the substrate. Furthermore, the present invention relates to an inkjet print head manufactured by the manufacturing method.

[0002]

2. Description of the Related Art Ink jet print heads are generally equipped with an ink ejection pressure generating element for generating energy used for ejecting ink, and are roughly classified into two types according to the ink ejection pressure generating element. One is that the ink ejection pressure generating element is an electrothermal conversion element, and the other is that the ink ejection pressure generating element is an electromechanical conversion element.

A general structure of such an ink jet print head will be described with reference to FIG. 8 in which an electrothermal converting element is used as an ink ejection pressure generating element.
In FIG. 8, reference numeral 100 denotes a thin film formed by electrothermal conversion elements (discharge heaters) arranged in a plurality of rows on a substrate made of Si and electric wiring (electrodes) such as Al for supplying electric power to the heaters. It is a heater board (substrate) formed by technology. Reference numeral 200 denotes a wiring board for the heater board 100, which is located at the end of the wiring (for example, connected by wire bonding) corresponding to the electrical wiring of the heater board 100 and receives an electric signal from the main unit. Pad 201 of FIG. 130
Reference numeral 0 denotes a grooved top plate provided with a partition wall for partitioning a plurality of ink flow paths communicating with the ejection ports and a common liquid chamber that is a portion for holding ink to be supplied to each ink flow path, The grooved top plate is integrally formed with an orifice plate having an ink receiving port 1500 for receiving the ink supplied from the ink tank and introducing it into the common liquid chamber, and an ejection port.

Reference numeral 300 denotes a support body made of, for example, a metal, which supports the back surface of the wiring board 200 on a plane and serves as a bottom plate of the ink jet print head. Reference numeral 500 denotes a pressing spring for pressing and fixing the heater board and the grooved top plate. The pressing spring 500 has an M-shaped cross-section in the flow path arrangement direction, and a front hanging portion 501 is provided in the vicinity of the discharge port. The foot provided on the presser spring is the hole 31 of the support 300.
The heater board and the grooved top plate are sandwiched by engaging with the back surface side of the support body 300 through 21 to generate a pressing force. At this time, the front drooping portion 501 centrally presses a part of the flow path, preferably a region near the discharge port, by linear pressure, and lightly presses the common liquid chamber at the center of the M-shaped portion. Furthermore, a sealant is provided around the joint between the heater board and the grooved top plate to prevent ink leakage from the ink flow path.

[0005]

However, in the conventional method in which the grooved top plate and the heater board are crimped and fixed only by the concentrated biasing force of the pressing spring as described above, when the warp of the grooved top plate is large, It is not possible to completely eliminate the gap generated at the joint between the attached top plate and the heater board. When this gap occurs at the junction of the partition walls of the ink flow path, the pressure for ejecting the ink in the ink flow path leaks to the adjacent ink flow path and the ink ejection force is attenuated or the leaked pressure causes So-called crosstalk that causes fluctuations in the ink meniscus at the ejection port occurs, resulting in uneven image quality due to changes in the ejection speed and ejection amount, and deterioration in image quality such as distortion. In addition, in a color type inkjet print head in which a plurality of inks are independently contained in such an inkjet print head,
There is a risk that the ink will mix colors from the gap.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an ink jet print head which prevents the occurrence of crosstalk and is excellent in image quality and reliability. To do. Another object of the present invention is to provide a color type ink jet print head having no color mixture between the flow paths. In the configuration of the present invention that achieves the above object, a substrate having an ink ejection pressure generating element and forming the bottoms of a plurality of ink channels is joined to a top plate that forms the ceiling of the plurality of ink channels. In the method for manufacturing an ink jet print head for forming the plurality of ink flow paths, one of the joints between the substrate and the top plate is Si and the other is metal, and the energy particles are provided at each of the joints. After irradiating, the substrate and the top plate are brought into contact with each other to bond the substrate and the top plate by room temperature bonding by surface activation. According to the present invention, since the substrate and the top plate are reliably joined by the room temperature joining due to the surface activation, it is possible to prevent a gap from being generated at the joining portion between the substrate and the top plate. Therefore, it is possible to provide an inkjet printhead which is free from the occurrence of crosstalk and has excellent image quality and reliability. Further, since it is not necessary to use a holding spring, it is possible to provide an inexpensive inkjet print head having a high yield. Further, in the case of a color type ink jet print head that independently contains inks of a plurality of colors, it is possible to provide an ink jet print head that does not mix colors between the flow paths.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The principle of room temperature bonding by surface activation, which is used for bonding the heater board (substrate) and the top plate in the present invention, will be described.
First, impurities and functional layers adhering to the metal and Si surfaces are physically removed by irradiation with energetic particles such as a high-speed electron beam to expose clean metal and Si surfaces. Since the exposed surfaces of the metal and Si thus cleaned are in an active state, the exposed surfaces are joined to each other so that the metal and Si on the exposed surfaces are bonded to each other to form a strong joined state between the metal and Si. Is what you can get. Here, as the metal used in the joining method, Al, C
Metals such as u and Ag can be used, but the present invention is not limited to these as long as they show a good bonding state with Si by surface activation.

Since the above-described joining method according to the present invention enables joining at room temperature, it does not require heating unlike the direct joining of metals in the conventional joining method. This is a method for directly joining metal surfaces without the use of an adhesive, and there is no structural change at the joining interface. Therefore, by using the above method for joining the substrate and the top plate of the inkjet head, it is possible to provide an inkjet head in which the substrate is not damaged by heat and the influence of crosstalk is small. In addition, since there is no protrusion of the adhesive in the flow path that occurs when joining the substrate and top plate with the adhesive, and there is no variation in the flow path height due to fluctuations in the adhesive thickness, highly reliable inkjet heads can be manufactured with high yield. can do.

In the present invention, the member formed of Si may be a heater board or a top plate. Further, the metal portion in the joint portion can be formed by making the heater board, the top plate and the like out of metal, but may be formed by forming a metal thin film at the joint portion of each member. By thus forming the metal portion of the joint portion with the metal thin film, the selectivity of the member is improved, and particularly by forming the member with resin or the like, it is possible to provide an inkjet head which is inexpensive and easy to manufacture.

In the present invention, the heater board and the top plate may have well-known structures, and at this time, the convex portion serving as the side wall of the ink flow path may be provided on the substrate side or the substrate side. It may be one. The substrate and the top plate in the present invention can be prepared by a known method.

[0011]

Embodiments of the present invention will be described below. [Embodiment 1] FIG. 1 shows a cross-sectional view of a top plate and a heater board in Embodiment 1 of the present invention. FIG. 2 is a detailed sectional view of the heater board in FIG. In the figure, in the heater board 100, HfB2 as a heating resistance layer was sputtered on the silicon substrate 1 to a thickness of 1000 Å, and Al as an electrode layer was sputtered thereon to a thickness of 5000 Å. After that, since the Si surface needs to be exposed at the joint with the top plate 1300, this layer is formed into a pattern as shown in FIG. 2 by using photolithography technology and etching technology, and a heating resistor made of HfB2 is formed. The element 2 and the electrode 3 made of Al were formed. SiO 2 was sputtered thereon to a thickness of 1 μm to form an oxidation resistant protective film 4, and Ta was sputtered thereon to a thickness of 0.2 μm to form a cavitation resistant film 5. Then, as shown in FIG. 1, a thin film forming means such as a spatter is used on the resinous top plate formed by molding or the like.
A thin film having a thickness of 1 μm was provided to form a bond. The material for forming the thin film is not limited to Al as long as it can be joined by surface activation.

Next, in order to join the heater board and the top plate, each is installed in a joining device. The joining device is composed of two vacuum chambers, a preliminary chamber and a pressure chamber, and the degree of vacuum is 10 −5 Pa. And, in the crimping room,
A saddle field type fast atom beam source (usually using inert Ar gas) is used to heat the Si of the heater board.
Energetic particles are applied to the joint between the surface and the top plate on which the Al thin film is formed. After activating the surface by this irradiation, the Si exposed portion 6 of the heater board and the joining portion 1306 of the top plate are joined.

After the top plate and the heater board have been joined as described above, a conventionally known head forming process has been performed, and then an ink supply member has been attached to obtain a liquid jet recording head. In the attachment of the ink supply member, since there was conventionally a gap between the nozzle portion and the heater board, the nozzle portion was also covered with the sealant to obtain a complete communication state. However, in this embodiment, since the nozzle portion is already bonded by room temperature bonding, it is not necessary to cover the nozzle portion with the sealant, and since the sealant is used only in the supply portion, the nozzle portion is not covered. The encapsulant did not wrap around, and the selectivity of the encapsulant was expanded, enabling the yield to be improved. Furthermore, by using room temperature bonding by surface activation to bond the top plate and the heater board, the bonding strength between the top plate and the heater board is strong, the gap is completely eliminated, and the occurrence of crosstalk phenomenon is prevented and the image quality is improved. Deterioration was prevented.

[Embodiment 2] FIG. 3 shows a sectional view of a top plate and a heater board in Embodiment 2 of the present invention. FIG. 4 is a detailed sectional view of the heater board in FIG. In the figure, the layer 10 composed of four layers such as a protective film on the substrate is provided with a taper 7-1 as shown in FIG. 4 by using a photolithography technique and an etching technique. Further, as shown in FIG. 3, the taper 7-
A taper 7-2 is provided so as to engage with 1. In this way, the taper 7-
By providing the engaging portion 7-1 that engages with 2, it is possible to shorten the engagement time at the time of joining the top plate and the heater board, and it is possible to widen the area of the joining portion and perform firm joining. Becomes Furthermore, the accuracy of the beam irradiation angle required for the heater board is reduced, and the productivity is improved.

[Third Embodiment] FIG. 7 is a perspective view of a color type ink jet head according to a third embodiment of the present invention. In the color type inkjet head as shown in FIG. 7, even if the bonding strength between the top plate and the heater board is sufficient and there is no gap between them, the inkjet head has an orifice plate as shown in FIG. In the case of having ink, color mixture of ink may occur due to a gap formed between the orifice plate and the heater board.

Therefore, as shown in FIG. 6, a joint portion is provided between the nozzles in which inks of different colors are adjacent to each other, and a joint portion of a thin film such as Al is formed on the joint portion of the orifice plate with the substrate. By forming 1306 ′, the bonding strength and the sealing property were improved by using the room temperature bonding by surface activation of the bonding portion and the Si surface of the heater board. Conventionally, the joint part of the orifice plate with the substrate is
Since the distance between the sheets becomes too long, it cannot be pressed with a spring or the like, and if an adhesive is used, the ink flow path will be clogged, so a good bonding state can be obtained at this part. However, according to the present embodiment, it is possible to satisfactorily bond the orifice plate with the substrate. Further, since the paper-to-paper distance is not taken more than necessary and the ink flow path is not clogged with the adhesive, it is possible to provide a highly reliable inkjet head having excellent landing accuracy. As a result, even in a color-type inkjet head, it is possible to separate ink colors, and it is possible to prevent deterioration of color image quality due to ink color mixing.

In the above embodiments, the so-called edge shooter type ink jet head for ejecting ink in a direction substantially perpendicular to the electrothermal conversion element which is the ink ejection pressure generating element is used, but the present invention is not limited to this. However, the ink jet head of the so-called side shooter type that ejects ink above the electrothermal conversion element also exhibits excellent performance. The present invention also includes a configuration in which an electromechanical conversion element is used as the ink ejection pressure generation element instead of the electrothermal conversion element.

[0018]

According to the present invention, the influence of crosstalk is small, and the flow path height due to the flow-out of the adhesive in the flow path and the fluctuation in the adhesive thickness which occur when the substrate and the top plate are joined by the adhesive. It is possible to manufacture a highly reliable inkjet head having no variation and high yield. By using the room temperature bonding by the surface activation to bond the top plate and the heater board, the bonding strength between the top plate and the heater board is strong, the gap is completely eliminated, the occurrence of crosstalk phenomenon is prevented, and the image quality is deteriorated. Can be prevented. Further, even in a color type inkjet head, it is possible to separate the colors of inks and prevent deterioration of color image quality due to color mixture of inks.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a top plate and a heater board according to a first embodiment of the present invention.

FIG. 2 is a detailed cross-sectional view of the heater board in FIG.

FIG. 3 is a cross-sectional view of a top plate and a heater board according to a second embodiment of the present invention.

FIG. 4 is a detailed cross-sectional view of the heater board in FIG.

FIG. 5 is a cross-sectional view of a conventional example of a color type inkjet head.

FIG. 6 is a cross-sectional view of a top plate and a heater board according to a third embodiment of the present invention.

FIG. 7 is a perspective view of a color type inkjet head.

FIG. 8 is a diagram of a conventional example of an inkjet head.

[Explanation of symbols]

1: Silicon substrate 2: Heating element 3: Electrode 4: Oxidation resistant protective film 5: Cavitation resistant layer 6: Si exposed portion 7-1: Four-layer taper such as protective layer on substrate 7-2: Heaven Taper that meshes with taper on board provided on plate 10: Layer consisting of 4 layers such as protective layer 100: Heater board 200: Wiring board 201: Pad 300: Support 400: Orifice plate 500: Presser spring 501: Front slant Part 1300: Top plate with groove 1306: Joining part by thin film such as Al 1306 ′: Joining part by thin film such as Al 1500: Ink receiving port 3121: Support hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirokazu Komuro 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Hideto Yokoi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takashi Fujikawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (12)

[Claims] 1. A plurality of inks are formed by bonding a substrate having an ink discharge pressure generating element and forming a bottom portion of a plurality of ink flow passages, and a top plate forming a ceiling portion of the plurality of ink flow passages. In the method for manufacturing an ink jet print head for forming a flow path, one of the joints between the substrate and the top plate is Si and the other is metal, and the joints are irradiated with energetic particles, and then the substrate And a top plate are brought into contact with each other to bond the substrate and the top plate by room temperature bonding by surface activation. 2. The method for manufacturing an ink jet print head according to claim 1, wherein the metal is any one of Al, Cu, and Ag. 3. The ink jet print head according to claim 1, wherein the Si is provided at a joint portion on the substrate side. 4. The ink jet print head according to claim 1, wherein the Si is provided at a joint portion on the top plate side. 5. The method for manufacturing an ink jet print head according to claim 1, wherein the substrate has a convex portion which is a side wall of the ink flow path and has the joint portion. 6. The method for manufacturing an ink jet print head according to claim 1, wherein the top plate has a convex portion that is a side wall of the ink flow path and that has the joint portion. 7. The method for manufacturing an ink jet print head according to claim 1, wherein the ink ejection pressure generating element is an electrothermal converting element. 8. The method for manufacturing an ink jet print head according to claim 7, wherein a functional layer is provided on the substrate. 9. The method for manufacturing an ink jet print head according to claim 8, wherein the substrate is made of Si, and the joint portion on the substrate side is formed by removing the functional layer at the joint portion of the top plate. . 10. The method of manufacturing an ink jet print head according to claim 1, wherein the top plate is made of resin, and the metal thin film is provided on at least a substrate bonding portion of the resin. 11. The method of manufacturing an ink jet head according to claim 1, wherein the plurality of ink channels independently contain a plurality of colors of ink. 12. The method of manufacturing an ink jet head according to claim 6, wherein an engaging portion corresponding to a convex portion provided on the top plate is provided at a joining portion of the substrates.