JPH10264394A - Ink-jet recording head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording head and its manufacture whereby a count of parts is reduced and a setting process is simplified, thereby reducing costs, and defective discharging of ink is solved. SOLUTION: A groove part 3 defining an ink passage is formed of a thick resin film layer 2 layered at the side of a substrate 1. A nozzle plate 4 has at least a joint part 6 directly connected to an ink tank and an ink feed pipe 7 supplying ink form the joint part 6 to the ink passage. The substrate 1 is bonded to the nozzle plate 4, whereby the ink-jet recording head is manufactured. Accordingly, a count of parts constituting the ink passage is reduced and a setting process is simplified, so that costs is decreased. Moreover sine the linear ink feed pipe 7 directly couples the joint part 6 with the individual ink passage, air bubbles are prevented from remaining and growing and defective discharging of ink or the like can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head used for an ink jet printer and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a structure of an ink jet recording head, for example, Japanese Patent Application Laid-Open No.
JP-A-246675 discloses an ink jet recording head in which a substrate on which a heating element is formed and a nozzle plate in which a fine ink flow path is formed by molding and a nozzle hole is processed are joined. This structure has a feature that the ink ejection direction is excellent because the opening of the nozzle hole, which is the ink ejection portion, is made of the same material and a circular ejection port can be formed.

FIG. 6 is an exploded perspective view showing an example of a conventional ink jet recording head, and FIG. 7 is a sectional view of the same. In the figure, 21 is a substrate, 22 is a nozzle plate, 23 is a heat sink, 24 is a spring, 25 is a manifold, 26 is an ink tank, 27 is an ink supply port, 28 is a joint,
29 is an ink supply path. Heating elements for heating the ink are arranged on the substrate 21. The nozzle plate 22 has a groove serving as an ink flow path corresponding to the heating element arranged on the substrate 21, a nozzle hole for discharging ink, and an ink supply for supplying ink to the ink flow path. An opening 27 and the like are formed. The heat sink 23 promotes heat radiation of the substrate 21 and also has wires for electric power, electric signals, and the like to be supplied to the heating element on the substrate 21. The spring 24 is used to press the nozzle plate 22 against the substrate 21. The manifold 25 is provided with a joint 28 connected to the ink tank 26, and an ink supply path 29 connecting the ink supply port 27 of the nozzle plate 22 and the joint 28 is formed.

At the time of assembling, for example, the substrate 21 is placed on the heat sink 23, the nozzle plate 22 is positioned and joined to the substrate 21, and then the nozzle plate 22 is pressed against the substrate 21 by the spring 24. Thus, individual ink flow paths corresponding to the heating elements are formed on the substrate 21. Thereafter, the manifold 25 is attached, the ink supply path 29 in the manifold 25 is connected to the ink supply port 27 of the nozzle plate 22, and an ink flow path from the joint 28 to the nozzle is formed. Thus, an ink jet recording head is manufactured. When the ink tank 26 is attached to the inkjet recording head, the ink outlet of the ink tank 26 is connected to the joint 28, and the ink tank 26
Is supplied to the ink supply path 29 in the manifold 25.
Is supplied from the ink supply port 27 of the nozzle plate 22 to each individual ink channel.

However, in such a configuration, the nozzle plate 22
There is a problem that the number of parts is large and the cost is high because the manifold 25 is interposed between the ink tank 26 and the ink tank 26. In addition, a sealing agent must be injected so that ink does not leak from a connection portion between the ink supply port 27 of the nozzle plate 22 and the ink supply path 29 of the manifold 25. There was also a problem that it took. Further, as shown in FIG. 7, the ink supply path 29 for supplying the ink from the ink tank 26 to the individual ink flow paths is a curved flow path, and a region where the ink flow is partially poor occurs. . This is difficult to remove, for example, when air bubbles are mixed or generated in the ink, and as a result, there is a possibility that ink ejection failure occurs.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and reduces the number of parts, simplifies the assembly process, reduces costs, and eliminates problems such as defective ink ejection. It is an object of the present invention to provide an ink jet recording head and a method of manufacturing the same, which have been solved.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an ink jet recording head in which a groove for forming an ink flow path is formed by a thick resin layer laminated on a substrate side, and is joined to a nozzle plate to form an ink flow path. Then, at least a joint portion directly connected to the ink tank and an ink supply pipe for supplying ink from the joint portion to the ink flow path are formed in the nozzle plate. This eliminates the need for the manifolds shown in FIGS. 6 and 7, reduces the number of parts, simplifies the assembly process, and reduces costs. Further, since the ink supply pipe can be directly connected from the joint portion to the individual ink flow path without bending the ink supply pipe, the area where the ink flow changes can be reduced, and ink ejection failure and the like can be avoided. .

[0008]

FIG. 1 is an exploded perspective view showing an embodiment of an ink jet recording head according to the present invention, and FIG.
FIG. In the figure, 1 is a substrate, 2 is a thick film resin layer, 3 is a groove, 4 is a nozzle plate, 5 is a nozzle hole, 6 is a joint, 7 is an ink supply path, 8 is an ink tank, 9 is a heat sink, and 10 is a heat sink. Ink drops.

On the substrate 1, a heating element (not shown) for heating the ink, and an energizing electrode (not shown) for supplying power to the heating element are provided. Further, a driving circuit for driving the heating element, various sensors, and the like may be provided. After these are formed, a thick resin layer 2 is laminated on the substrate 1. At this time, in order to form an ink flow path corresponding to the heating element, the groove portion 3 is formed by removing the thick film resin layer 2 only in the ink flow path portion. The material of the thick resin layer is not particularly limited as long as it has ink resistance. For example, a polyimide, a dry film resist, a solder resist, or the like can be applied since a fine pattern can be relatively easily formed.

The nozzle plate 4 is provided with a nozzle hole 5 serving as an ink discharge port, an ink supply path 7 for supplying ink in the ink tank 8 to individual ink flow paths, and is directly connected to the ink tank 8. Joint portion 6 is provided.
In this example, the portion of the nozzle plate 4 that faces the substrate 1 and that forms the ink flow path is a flat surface. Further, since the ink supply path 7 forms a linear flow path from the joint section 6 to the ink flow path, the ink supply path 7 is configured such that there is no bent portion such as the ink supply path 29 shown in FIG. it can. Therefore, it is possible to reduce the residual and growth of bubbles and the like mixed in the ink, and to eliminate the ink ejection failure. The material of the nozzle plate 4 is not particularly limited as long as the material has ink resistance. For example, when the nozzle plate 4 is formed by molding, polysulfone, polyether sulfone, poly Engineering plastics such as ether imide can be used.

The heat sink 9 is made of a material having good heat conductivity, and the substrate 1 is joined to the heat sink 9 by, for example, an adhesive having good heat conductivity. Wirings for supplying electric power, electric signals, and the like to the heating elements on the substrate 1 are also formed on the heat sink 9, and are electrically connected to the current-carrying electrodes on the substrate 1. It is electrically connected.

The ink tank 8 holds ink inside and supplies ink from the joint 6 of the nozzle plate 4. When the ink jet recording head is configured, the ink tank 8 may be formed integrally or may be detachable so as to be replaceable.

Next, an example of a method of manufacturing the above-described ink jet recording head according to an embodiment will be described. First, after a heating element (not shown), a current-carrying electrode, and the like are formed on the substrate 1 by an LSI process or the like, a thick resin layer 2 is laminated to form a groove 3. For forming the thick resin layer 2, for example, when a photosensitive material is used as the material of the thick resin layer 2, a so-called photolithography technique of patterning by exposure and development can be applied. In addition, a pattern can be formed by an ablation process using an excimer laser or an etching process using a non-photosensitive substance.

On the other hand, the outer shape of the nozzle plate 4, the ink supply path 7, the joint 6 and the like are formed by molding. Thereafter, the nozzle hole 5 is formed. As a specific processing method of the nozzle hole 5, an ablation process using an excimer laser, in which an excimer laser is irradiated through a mask and holes are accurately formed in accordance with a pixel pitch, is appropriate. According to this, there is almost no thermal effect during processing,
A pattern as designed by the mask can be formed.

In this embodiment, fine grooves corresponding to individual ink flow paths are not formed in the nozzle plate 4. When such a nozzle plate 4 is manufactured, if a shape in which a fine shape and a large shape are mixed is formed, accuracy deteriorates due to heat shrinkage and the like. However, in the nozzle plate 4 as described above, since a fine shape such as an ink flow path is not formed by molding, there is no portion that poses a problem in precision during molding, and the conventional configuration as shown in FIGS. Nozzle plate 22 in
And the manifold 25 can be integrally formed.
In addition, since a fine structure does not need to be processed at the time of molding, molding can be easily performed. Further, even when the nozzle hole 5 is processed, for example, there is no positional deviation or interference with a minute shape such as an ink flow path, so that high-precision processing is possible.

The substrate 1 thus formed and the nozzle plate 4 are aligned and joined. As means of joining,
A method of applying a thin adhesive to the upper part of the thick resin layer 2 of the substrate 1 and bonding the same, a method of mechanically pressing the nozzle plate 4 against the substrate 1 by a leaf spring or a wire spring, or a method of bonding the thick resin layer 2 A method of directly joining as a layer can be applied. By this joining, the groove 3 on the substrate 1 and the substrate 1 of the nozzle plate 4
And the surface facing each other, each individual ink flow path is formed. In particular, although the mechanical pressing method requires a pressing structure, it can be performed at room temperature without the need for heat at the time of bonding, so that positional displacement due to a difference in the coefficient of thermal expansion between the substrate 1 and the nozzle plate 4 is prevented. It has the advantage of being able to be used, and is particularly effective for joining different materials. By joining the substrate 1 and the nozzle plate 4, individual ink flow paths and ink flow paths communicating with the nozzle holes 5 from the joint portions 6 formed on the nozzle plate 4 via the ink supply paths 7 are formed. it can. Thereafter, a sealant is injected between the side surface of the substrate 1 on the nozzle hole 5 side and the nozzle plate 4, and this portion is sealed.

According to such a structure, in the ink jet recording head of the present invention shown in FIGS. 1 and 2, for example, as compared with the conventional ink jet recording head as shown in FIGS. Since the nozzle plate 4 integrated with the nozzle plate 25 is used, the number of components is reduced, so that an inexpensive inkjet recording head can be manufactured. Also, during assembly, the number of parts to be assembled is small,
Since the number of ink flow path connection portions is small, the number of steps such as sealing can be reduced, and the assembling process can be greatly simplified.

The heat sink 9 and the substrate 1 are bonded before the substrate 1 and the nozzle plate 4 are bonded. That is, first, the substrate 1 is bonded to the heat sink 9,
Thereafter, the nozzle plate 4 can be assembled in a procedure of joining the nozzle plate 4 to the substrate 1. Alternatively, the substrate 1 and the nozzle plate 4 may be joined as described above, and the assembly may be joined to the heat sink 9. Thus, an ink jet recording head can be manufactured. In the case of a structure integrated with the ink tank 8, the ink jet recording head is manufactured by joining the ink tank 8 further.

FIG. 3 is a sectional view showing a modified example of the nozzle plate 4 in one embodiment of the ink jet recording head of the present invention, FIG. 4 is a sectional view taken along the line AA, and FIG. It is. In the figure, reference numeral 11 denotes a joining recess. In this example, the nozzle holes 5 of the nozzle plate 4 correspond to the partition walls separating the grooves 3 formed by the thick resin layer 2 on the substrate 1.
Is provided with a joining recess 11 having a step formed on the surface of the hole. The bonding recess 11 is fitted with a partition formed by the thick resin layer 2 when the substrate 1 and the nozzle plate 4 are bonded. Thus, the substrate 1 and the nozzle plate 4 are fitted and adhered to each other only by pressing the substrate 1 and the nozzle plate 4 at the time of assembling, the sealing property around the nozzle hole 5 is improved, and the leakage and pressure of the ink from the ink flow path are increased. Leakage and the like can be prevented. Further, even when the sealant injected between the side end of the substrate 1 and the nozzle plate 4 tries to flow into the ink flow path, this fitting fits the sealant into the ink flow path. Intrusion can be prevented, and ejection failure due to narrowing or blockage of the ink flow path can be prevented.

As a method of processing the joint concave portion 11 provided in the nozzle plate 4, laser processing, molding, cutting, or the like can be applied, and it is also possible to perform processing with higher precision by combining these.

In the above example, the nozzle hole 5 is formed in the nozzle plate 4. However, the end portion of the groove 3 may be left open and the nozzle may be used as a nozzle.

[0022]

As is apparent from the above description, according to the present invention, since the ink flow path from the ink tank to the individual ink flow path is constituted only by the nozzle plate, the number of parts can be reduced. At the same time, the assembly process can be simplified and the cost can be reduced. Therefore, an inexpensive inkjet recording head can be manufactured. Further, since the flow path of the ink from the ink tank to the individual ink flow path can be configured linearly, it is possible to reduce ink ejection failure due to bubbles in the ink and to always obtain good image quality. There is an effect that an ink jet recording head can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an ink jet recording head according to the present invention.

FIG. 2 is a cross-sectional view illustrating an embodiment of the inkjet recording head of the present invention.

FIG. 3 is a cross-sectional view showing a modified example of the nozzle plate 4 in one embodiment of the inkjet recording head of the present invention.

FIG. 4 is an AA sectional view showing a modified example of the nozzle plate 4 in one embodiment of the ink jet recording head of the present invention.

FIG. 5 is a perspective view of a main part showing a modified example of the nozzle plate 4 in one embodiment of the inkjet recording head of the present invention.

FIG. 6 is an exploded perspective view showing an example of a conventional ink jet recording head.

FIG. 7 is a cross-sectional view illustrating an example of a conventional inkjet recording head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... board | substrate, 2 ... thick film resin layer, 3 ... groove part, 4 ... nozzle plate,
5 ... nozzle hole, 6 ... joint part, 7 ... ink supply path,
8: ink tank, 9: heat sink, 10: ink drop, 11: joining recess.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Katsuhide Ogawa 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd.

Claims (6)

[Claims] 1. An ink jet recording head in which a substrate on which a heating element for heating ink is arranged and a nozzle plate are joined to form an ink flow path corresponding to the heating element, a thick resin layer is formed on the substrate. The thick film resin layer is formed with a groove serving as the ink flow path. The nozzle plate includes a joint directly connected to an ink tank, and an ink for supplying ink from the joint to the ink flow path. An ink jet recording head having at least a supply pipe. 2. The nozzle plate has a nozzle hole for discharging ink corresponding to the ink flow path, and separates the groove on the substrate from a surface where the nozzle hole is formed. An ink jet recording head, wherein a step portion corresponding to a partition wall made of a thick resin layer is formed, and the partition wall is fitted with the step portion. 3. A method of manufacturing an ink jet recording head in which a substrate on which a heating element for heating ink is disposed and a nozzle plate are joined to form an ink flow path corresponding to the heating element, wherein the heating element is provided on the substrate. After arranging, a thick film resin layer is formed such that the ink flow path portion becomes a groove, and a joint part directly connected to an ink tank and an ink supply pipe for supplying ink from the joint part to the ink flow path are formed. A method for manufacturing an ink jet recording head, comprising: forming at least a nozzle plate provided by molding; and joining the substrate and the nozzle plate. 4. The method according to claim 3, wherein an ink discharge nozzle hole corresponding to the ink flow path is formed in the nozzle plate by ablation processing using an excimer laser, and then the substrate is joined to the substrate. A method for manufacturing an ink jet recording head. 5. A step portion corresponding to a partition wall made of the thick film resin layer separating the groove on the substrate is formed on a surface of the nozzle plate where the nozzle hole is formed, and a step portion of the substrate and the nozzle plate is formed. The method according to claim 4, wherein the step portion and the partition wall are fitted at the time of joining. 6. The step portion is formed by molding, a combination of molding and laser processing, a combination of cutting and laser processing, or only laser processing.
3. The method for manufacturing an ink jet recording head according to item 1.