JPH10100417A - Ink jet recording head and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head and a manufacturing method thereof not affected by lacking or protruding of an adhesive by a method wherein a substrate and a nozzle plate are bonded to each other without using the adhesive. SOLUTION: A resin layer 5 is provided to a top layer of a substrate 1 and it is prebaked so as not to be adhesive. Patterning is applied to the resin layer 5 except at least on ejection elements. A nozzle plate 7 in which nozzles 6 are formed is formed in another process. The nozzle plate 7 and substrate 1 are aligned with each other, pressed and heated at the same time. As a result, the resin layer 5 is cured and the substrate 1 and nozzle plate 7 are bonded to each other at a bonding face 8.

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 An ink jet recording head used in an ink jet printer is formed by joining a substrate provided with an ejection element for ejecting ink and a nozzle plate provided with an ink flow path corresponding to the ink ejection element. Have been. As an ejection element for ejecting ink, an element using a heating element for heating ink, an element using a piezoelectric element, and the like are known. As described in JP-A-63-34152, the bonding between the substrate and the nozzle plate is performed as follows.
A method using a thermosetting adhesive applied by a transfer method is used.

However, when the substrate and the nozzle plate are bonded to each other using an adhesive, it is difficult to control the amount of the adhesive applied, and the shortage of the adhesive causes ink leakage or pressure propagation to an adjacent flow path. In addition, there is a problem that the flow path of the ink is narrowed due to the protrusion, and a discharge failure occurs.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and is intended to be affected by a shortage or protrusion of an adhesive by bonding a substrate and a nozzle plate without using an adhesive. It is an object of the present invention to provide an ink jet recording head and a method of manufacturing the same.

[0005]

According to a first aspect of the present invention, in the ink jet recording head, a substrate provided with an ejection element for ejecting ink and an ink flow path corresponding to the ink ejection element are formed. In an ink jet recording head in which a nozzle plate is joined, a resin layer is formed on the substrate, and the substrate and the nozzle plate are bonded by the resin layer.

According to a second aspect of the present invention, in the ink jet recording head according to the first aspect, the resin layer is made of polyimide.

According to a third aspect of the present invention, in the ink jet recording head according to the first aspect, the resin layer is a dry film resist or a solder resist.

According to a fourth aspect of the present invention, in the method for manufacturing an ink jet recording head, a substrate provided with an ejection element for ejecting ink and a nozzle plate provided with an ink flow path corresponding to the ink ejection element are provided. In the method for manufacturing an ink jet recording head to be joined, a resin layer is patterned on the uppermost layer of the substrate, aligned with the nozzle plate, pressurized and heated to cure the resin layer, and the substrate and the nozzle plate are bonded. It is characterized by matching.

According to a fifth aspect of the present invention, in the method for manufacturing an ink jet recording head, a substrate provided with an ejection element for ejecting ink and a nozzle plate provided with an ink flow path corresponding to the ink ejection element are provided. In the method for manufacturing an ink jet recording head to be joined, a resin layer is patterned on the uppermost layer of the substrate, and then heated, treated with an alkaline solution to soften the surface, aligned with the nozzle plate, pressurized and reheated. Then, the resin layer is cured and the substrate and the nozzle plate are bonded to each other.

[0010]

1 to 6 are schematic views for explaining a structure of an ink jet recording head and a method for manufacturing the same according to a first embodiment of the present invention. In this schematic diagram, four injection elements are shown, but it is not to be understood that the number of injection elements is limited to four, and that a large number of injection elements are arranged in an appropriate pattern such as being arranged in a row or in a zigzag pattern. The elements are arranged. In the drawing, 1 is a substrate, 2 is an ejection element, 3 is an insulating protective layer, 4 is a cavitation resistant film, 5 is a resin layer, 6 is a nozzle, 7 is a nozzle plate, 8 is an adhesive surface, and 9 is an ink droplet.

FIG. 1A is a plan view of the substrate 1, and FIG. 1B shows a cross section taken along line AA of FIG. For example, silicon is used as the material of the substrate 1, and the ejection element 2 is formed on the surface thereof. In this embodiment, a heating resistor was used as the ejection element 2. Before the injection element 2 is formed on the surface of the substrate 1, a step of forming a heat storage layer or an insulating layer may be interposed. However, since the formation of these layers is not related to the essence of the present invention, a description will be given. Is omitted. Further, an electrode for supplying a current to the heating resistor, which is the injection element 2, is formed, but the description of the process is omitted.

FIG. 2 shows a process of forming the insulating protective film 3.
Although the insulating protection film 3 may be provided for each of the ejection elements 2, in this embodiment, the insulating protection film 3 is formed in common for the plurality of ejection elements 2.

FIG. 3 shows a step of forming the anti-cavitation film 4. When the heating element is used as the ejection element 2, the anti-cavitation film 4 protects the ejection element 2 and the insulation protection from so-called cavitation in which ink suddenly flows in and collides when bubbles generated by heat generation of the ejection element 2 disappear. It is provided to protect the film 3. The anti-cavitation film 4 is provided for each ejection element 2, and is patterned after the anti-cavitation film 4 is deposited. As a material of the anti-cavitation film 4, a high melting point metal such as tantalum, tantalum nitride, hafnium boride, or a compound thereof can be used.

FIG. 4 shows a step of forming the resin layer 5. FIG.
FIG. 4A is a plan view, and FIG.
Shown in The resin layer 5 is formed as a protective layer and a flattening layer. As a material used for the resin layer 5 so as to minimize the thermal expansion because it is heated at the time of bonding described later, a low-temperature cured polyimide such as Ubicoat of Ube Industries, Ltd. is suitable. As a process, after uniform application by spin coating, pre-baking is performed to a degree not sticky. The pattern is formed so as to remove the ejection element 2 as shown in FIG. As a patterning method, there is a method of performing wet etching or dry etching after a photolithographic process, or a method of directly applying an excimer laser.

As the resin layer 5, other than polyimide, a dry film resist or a solder resist may be used as another material. When a dry film resist is used, the resin layer 5 may be formed by lamination instead of spin coating.

In the above steps, the substrate 1 corresponding to one ink jet recording head is illustrated. However, when a wafer is used as the substrate, a large number of substrates 1 are formed on one wafer. Then, the substrate 1 as shown in FIG. 4B is cut out one by one by dicing.
Can be obtained. In this case, it is preferable to remove the resin layer 5 on the cutting line by dicing.

On the other hand, in another step, the nozzle plate 7 is formed. The nozzle plate 7 is formed with a common liquid chamber groove, an individual flow path groove communicating with the common liquid chamber, and corresponding to each ejection element 2. In some cases, the individual channel grooves and the like are formed by patterning the resin layer 5 of the substrate 1. In the roof shooter type ink jet recording head, nozzles 6 are formed on the nozzle plate 7 at positions above the ejection elements 2. Here, polysulfone was used as the material of the nozzle plate 7. However, other materials having heat resistance and ink resistance, such as a resin such as polyether sulfone and a metal such as silicon, can be used.

FIG. 5 shows a joining process of the substrate 1 and the nozzle plate 7. FIG. 5A is a plan view, and FIG. 5B shows a cross section taken along line AA. As shown in FIG. 5A, the nozzle plate 7 manufactured in another step is positioned on the substrate 1 manufactured through the steps up to FIG. 4, and is heated while being pressurized. Thereby, the resin layer 5 is cured, and the substrate 1 and the nozzle plate 7 are bonded on the bonding surface 8. Although the heating temperature depends on the material of each member to be used, it is desirable that the heating be performed at, for example, 160 ° C. or lower. If it exceeds this, the positional deviation due to thermal expansion of the nozzle plate 7 increases. In addition, cracks in the nozzle plate 7 due to internal stress frequently occur.

In this way, the substrate 1 can be used without using an adhesive.
And the nozzle plate 7 can be bonded to each other, so that there is no shortage of the adhesive and no protrusion, and good bonding can be performed. After the connection between the substrate 1 and the nozzle plate 7, electrical connection and channel connection with the ink tank are performed, but these are not shown. FIG. 6 is a conceptual diagram showing a state where ink droplets 9 are being ejected from the nozzles 6 by the completed inkjet recording head.

FIG. 7 is a schematic diagram for explaining a method of manufacturing an ink jet recording head according to the second embodiment of the present invention. In the figure, the same parts as those in FIGS. 1 to 6 are denoted by the same reference numerals, and description thereof will be omitted. 11 is a wafer, 1
2 is a cutting position and 13 is an alkaline solution. In this example,
A case where a plurality of substrates 1 shown in the above-described first embodiment are formed on a wafer 11 is illustrated. Not limited to this,
The substrates 1 may be formed individually.

In FIG. 7A, the ejection elements 2 and wirings for a plurality of substrates 1, an insulating protective film 3, an anti-cavitation film 4, and the like are formed on a wafer 11. This step is the same as that shown in FIGS. 1 to 3 when viewed in units of the individual substrates 1.

In FIG. 7B, a resin layer 5 is formed. The pattern is the same as in FIG. However, a low-temperature cure type polyimide is not used here, but a high-temperature cure type polyimide is used. For example, OCG750 as photosensitive polyimide
5 or the like can be used. After applying polyimide on the wafer 11 by spin coating, prebaking is performed. exposure,
After the development process, patterning is performed as shown in FIG. Thereafter, the resin layer 5 is cured by heating. The heating temperature is about 350 ° C. for the above-mentioned materials.

In FIG. 7C, each substrate 1 is cut at a cutting position 12 by dicing or the like in a state where the resin layer 5 is cured. In this case, since the resin layer 5 is hardened, cutting can be performed even if the resin layer 5 is provided at the cutting position 12.

Each cut substrate 1 is treated with an alkaline solution 13 in FIG. 7D to modify the surface of the resin layer 5. As a result, the surface of the resin layer 5 is softened, and the resin layer 5 is brought into a favorable state for adhesion. In FIG. 7D, the liquid is immersed in the alkaline liquid 13, but various conventionally used liquid treatment methods such as coating and spraying can be used.

Then, as shown in FIG. 5 described above, after the nozzle plate 7 is positioned, it is heated again while being pressed against it. The temperature here is the same as in the first embodiment.
It is desirable to be 60 ° C. or lower. Thereafter, electrical connection and flow path connection with the ink tank are performed in the same manner as in the first embodiment.

As described above, also in the manufacturing method shown in the second embodiment, the substrate 1 and the nozzle plate 7 can be bonded together without using an adhesive. No good occurs and good bonding can be performed.

FIG. 8 is a schematic sectional view showing an example of another type of ink jet recording head to which the present invention can be applied. The reference numerals in the drawings are the same as those in the above-described drawings, and the description is omitted. Note that the insulating protective layer 3 and the anti-cavitation film 4
And the like are not shown. In each of the above-described embodiments, a roof shooter type ink jet recording head is finally manufactured. However, ink droplets may be jetted in parallel with the surface of the jetting element 2 as shown in FIG. The above-described manufacturing method can be applied to a so-called side shooter type ink jet recording head that discharges ink in an oblique direction as shown in FIG. These types of ink jet recording heads differ only in the shape of the nozzle plate 7. In the configuration shown in FIG. 8A, both the substrate 1 and the nozzle plate 7 are formed of, for example, silicon or the like.
In the configuration shown in FIG. 8B, the nozzle plate 7 is formed by resin molding, and the nozzle 6 is laser-processed. In any case, the resin layer 5 on the substrate 1 and the nozzle plate 7
Are adhered as described above.

Also, other than the thermal type ink jet recording head using a heating resistor as the ejection element 2,
For example, even in the case of other types of ink jet recording heads such as those using a piezoelectric element as the ejection element 2, an ink jet recording head formed by forming a resin layer on a certain member and joining another member to the resin layer If so, it can be easily applied.

[0029]

As is apparent from the above description, according to the present invention, since no adhesive is used, there is no defect due to shortage or protrusion of the adhesive, and a high quality ink jet recording head can be obtained. In addition, since there is no need for a step of applying an adhesive, which is conventionally required, there are various effects such as a reduction in the number of manufacturing processes and a reduction in cost.

[Brief description of the drawings]

FIG. 1 is a part of a schematic view for explaining a head configuration and an assembling method according to a first embodiment of the present invention.

FIG. 2 is a part of a schematic diagram for explaining a head configuration and an assembling method according to the first embodiment of the present invention.

FIG. 3 is a part of a schematic view for explaining a head configuration and an assembling method according to the first embodiment of the present invention.

FIG. 4 is a part of a schematic diagram for explaining a head configuration and an assembling method according to the first embodiment of the present invention.

FIG. 5 is a part of a schematic diagram for explaining a head configuration and an assembling method according to the first embodiment of the present invention.

FIG. 6 is a part of a schematic view for explaining a head configuration and an assembling method according to the first embodiment of the present invention.

FIG. 7 is a schematic diagram for explaining a method for manufacturing an ink jet recording head according to a second embodiment of the present invention.

FIG. 8 is a schematic sectional view showing an example of another type of ink jet recording head to which the present invention can be applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Injection element, 3 ... Insulation protective layer, 4 ... Anti-cavitation film, 5 ... Resin layer, 6 ... Nozzle, 7 ... Nozzle plate, 8 ... Adhesive surface, 9 ... Ink droplet, 11 ... Wafer, 12 …
Cutting position, 13 ... Alkaline liquid.

Claims (5)

[Claims] 1. An ink jet recording head comprising a substrate provided with an ejection element for ejecting ink and a nozzle plate provided with an ink flow path corresponding to the ink ejection element, wherein a resin layer is provided on the substrate. Wherein the substrate and the nozzle plate are bonded together by the resin layer. 2. The ink jet recording head according to claim 1, wherein said resin layer is made of polyimide. 3. The method according to claim 1, wherein the resin layer is a dry film resist or a solder resist.
3. The ink jet recording head according to item 1. 4. A method for manufacturing an ink jet recording head for joining a substrate provided with an ejection element for ejecting ink and a nozzle plate provided with an ink flow path corresponding to the ink ejection element, wherein the uppermost layer of the substrate is provided. A method for manufacturing an ink jet recording head, comprising: patterning a resin layer, aligning the resin layer with the nozzle plate, curing the resin layer by applying pressure and heating, and bonding the substrate and the nozzle plate. 5. A method for manufacturing an ink jet recording head for joining a substrate provided with an ejection element for ejecting ink and a nozzle plate provided with an ink flow path corresponding to the ink ejection element, wherein the uppermost layer of the substrate is provided. Heat treatment after patterning the resin layer, softening the surface by treatment with an alkaline solution, aligning with the nozzle plate, pressurizing and reheating to cure the resin layer, the substrate and the nozzle plate A method for manufacturing an ink jet recording head, characterized by laminating.