JPH0311904B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nozzle manufacturing method effective for improving the reliability of inkjet recording technology, and particularly to an improvement in a nozzle manufacturing method applying plating technology.

Over the years, various attempts have been made to commercialize ink recording technology, which performs recording by jetting ink toward a recording medium from a fine nozzle, but in terms of reliability, true practical application has yet to take place. I have not yet reached the point where I have achieved this goal. The main reason for this is that in inkjet recording technology, the structure and processing precision of the ink jetting nozzle have a large effect on the jetting characteristics. In particular, conventional flat plate nozzles have the disadvantage that the end faces of the nozzles tend to become dirty due to the adhesion of dust from the outside or ink from inside the nozzles. For this purpose, as shown in FIG. 1, a nozzle tip portion 101 having an injection port is formed into a straight tube shape, and the wall thickness around the injection port is made thinner, and the other end has a sufficient hole diameter and wall thickness compared to the tip portion. A nozzle for an inkjet recording head having a large adhesive flange 102 was developed, and at the same time a technique for producing such a nozzle in large quantities at low cost was disclosed in Japanese Patent Application No. 57-216711.

FIGS. 2a to 2f are diagrams for explaining the manufacturing process of the conventional nozzle.

In other words, in the same figure, the nozzle is formed by plating a matrix made of a conductive flat plate member having a hole 201 that is exactly female with respect to the outer shape of the nozzle, and then mechanically peeling it off. Created. In addition, it is a low-cost material for nozzle formation.
Nickel is used because of its corrosion resistance and mechanical strength.

In the conventional manufacturing process of inkjet nozzles, a material that forms a stable passive film on the surface of the material, such as stainless steel, is used as the matrix material, which generally eliminates the need for peeling treatment. good. However, if the surface treatment of this stainless steel is a little rough, for example, the adhesion surface area increases, so when the nickel plating is applied, the adhesion strength is quite large, and when this is mechanically peeled off, the thin plating at the nozzle tip becomes thin. There was a problem that the parts were damaged or deformed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet recording nozzle manufacturing method for eliminating the above-mentioned drawbacks and manufacturing highly accurate nozzles with good yield.

According to the present invention, the conductive material has micropores that penetrate the flat plate member perpendicularly and have a cross-sectional area that gradually decreases from the front surface to the back surface and becomes the smallest at the opening on the back surface and in the vicinity thereof. a step of using a flat plate member as a female matrix, and forming a blocking layer for separating the back surface of the matrix from the plating solution and blocking the back opening of the through hole; and the surface of the matrix. forming an insulating layer to prevent the formation of a plating layer on unnecessary parts of the matrix, and forming a first plating layer on the necessary parts of the surface of the mother mold around the opening of the through-hole and on the inner surface of the through-hole. A method for producing a nozzle for inkjet recording, comprising the steps of: forming a second plating layer on the plating layer; and peeling off the plating layer. can get.

The present invention will be described in detail below with reference to the drawings.

3a to 3g are diagrams for explaining the first embodiment of the nozzle manufacturing method of the present invention, which is manufactured by the following process. In other words, Figure 3a
As shown in FIG. 3, a conductive flat plate member 3 has a hole 301 that is exactly female-shaped with respect to the outer shape of the nozzle.
A nozzle is formed by a plating method using 02 as a matrix. The hole 301 penetrates from the front surface 303 of the flat plate member 302 to the back surface 304, and its cross-sectional area gradually decreases from the front surface toward the back surface, and becomes a constant and minimum value near the back surface.

Since the flat plate member 302 is precisely processed, it is necessary to use it repeatedly as a plating matrix, and the matrix material is made of a material that forms a stable passive film on the surface of the material, such as stainless steel. do.

Next, as shown in FIG. 3B, a blocking layer 308 is formed to separate the back surface 304 of the mother die 302 from the plating solution and to close the back opening 306 of the through hole 301. As the material for the blocking layer 308, various organic materials formed in the form of a film can be used, and a preferable example is a dry film photoresist material. This is available, for example, under the trade name Laminar AX manufactured by Dynachem in the United States. Next, as shown in FIG. 3c, the matrix 30
In order to selectively plate the surface 303 of 2,
A predetermined pattern of an insulating layer 307 is formed on the surface 303. Although various photoresist materials can be used as the material for the insulating layer 307, the dry film resist material mentioned above is a preferred example. For example, laminar manufactured by Dynachem in the United States
When using AX, first a film-like photoresist material is attached to the surface of the matrix at a temperature of 93 to 110°C. Next, using a photomask on which a desired pattern has been formed in advance, the photomask pattern is printed onto the film resist layer using an exposure device using a high-pressure or ultra-high-pressure mercury lamp as a light source. Next, by developing in a predetermined weakly alkaline developer, the resist layer in non-exposed areas is dissolved and removed, and a predetermined pattern of the insulating layer is formed. In this pattern, the insulating layer 307 is the surface opening 3 of the through hole 301.
It is formed so as to surround a surface 303 centered at 05.

Next, as shown in FIG. 2d, a first plating layer 310 is formed on the portion of the mother mold surface 303 where there is no insulating layer and on the inner surface of the through hole 301 by a plating technique. The first plating layer is characterized by a weaker adhesive force with the matrix than the second plating layer described in the next step. That is, although the master mold 302 is precision-machined and used repeatedly as described above, it is currently difficult to obtain the desired precision including the surface roughness inside the hole. For this reason, for example, when the second plating layer described later is directly plated on the matrix, depending on the surface roughness inside the hole and the machining accuracy of the matrix, the adhesive force between the matrix and the plating layer may be quite large. As a result, when the plated part is removed from the matrix in the final process, the thinned part of the straight pipe part at the tip of the nozzle may be damaged or deformed, causing a decrease in yield.

In order to solve these conventional drawbacks, when plating a matrix material, a metal with weaker adhesive force than the main material is used as the first plating layer, and the metal layer serving as the main material is This is the second plating layer.

For example, when stainless steel is used as the matrix and corrosion-resistant nickel is used as the main material, it is preferable to use gold as the first plating layer. The thickness of this first plating layer is 1 to 2 μm, which is enough to separate the matrix material and the second plating layer, which is the main material.
m is sufficient, and even if a noble metal such as gold or platinum is used for the first plating layer, the cost will not increase significantly. By providing this first metal layer, it is possible to absorb variations in adhesive strength due to variations in precision machining of the matrix, and it is possible to peel off the nozzle in the final process without damaging or deforming it. .

Next, as shown in FIG. 3e, a second plating layer, which is the main material, is further plated on the first plating layer.

As the second plating material, one is selected that has sufficient corrosion resistance to the ink used and is inexpensive. As mentioned above, as a preferable example of this, stainless steel is used as the matrix material, gold is used as the material of the first metal layer, and nickel is used as the second metal layer. Of course, it goes without saying that the second metal layer is not limited to nickel.

For nickel plating, there is a sulfamic acid nickel bath, which has a small internal stress in the plating layer and can be used at high current densities even at low temperatures.

After the plating process of the second plating layer is completed,
As shown in FIG. 3f, the insulating layer and the barrier layer are removed from the front surface 303 and back surface 304 of the master mold, respectively. For example, when the dry film photoresist Laminar AX mentioned above is used as these layers, it can be removed by immersion in a caustic soda solution for 30 minutes.

Finally, the second metal plating layer 309 is mechanically peeled off as shown in FIG. 3g. As a result, a nozzle having an external shape completely opposite to that of the through-hole of the master mold is obtained. In this case, the first metal layer 310 is usually adhered to the second metal layer side 309 and does not remain on the mother mold side.

FIGS. 4a to 4h are diagrams for explaining a second embodiment of the nozzle manufacturing method of the present invention, which is manufactured by the following process.

That is, the processes a to e are the same as those in the first embodiment, and in the process f, the middle chamber disc member 41 is attached to the brim portion of the second plating layer 409.
1 is fixed with adhesive or the like. In this case, the material of the disc member is preferably the same as or similar to the second plating layer in view of thermal expansion during curing of the adhesive, corrosion resistance to ink, cost, etc. Next, as shown in FIG. 4g, the first and second plating layers and the disk member 411 are mechanically peeled off as one body. Furthermore, as shown in FIG. 4h, an insulating layer 407
and 408 and cleaning the master mold completes the process.

The nozzle obtained by the above process has a wall thickness that decreases continuously from the inlet toward the nozzle tip, and is thinnest near the nozzle tip. The reason for this is that the hole 301 is
This is because the more the plating liquid goes inside the hole 301, the more difficult it is to stir the plating liquid sufficiently, and the electric field distribution becomes weaker inside the hole 301, and the plating current becomes smaller inside the hole. In one embodiment of the pricking process mentioned above, while the wall thickness of the nozzle tip is 10 μm, the wall thickness of the nozzle inlet and the flange around it is approximately 50 μm.
It was confirmed that m.

As is clear from the above explanation, according to the present invention, highly reliable nozzles can be easily manufactured with high yield, and by using a matrix having a large number of through holes, it is possible to manufacture them in large quantities. .

[Brief explanation of drawings]

FIG. 1 is a sectional view of a nozzle obtained by the present invention;
FIGS. 2a to 2f are schematic diagrams of steps for explaining a conventional nozzle manufacturing method, and FIGS. 3a to 3g are process schematic diagrams of a first embodiment of the nozzle manufacturing method according to the present invention. Figures 4a to 4h are process schematic diagrams of the second embodiment of the nozzle manufacturing method according to the present invention, respectively 101... nozzle end, 102... adhesive flange, 201... hole, 202... flat plate. Element,
203...Front surface, 204...Back surface, 205...Surface opening, 206...Back surface opening, 207...Insulating layer, 208...Blocking layer, 209...Plating layer, 3
01... Hole, 302... Flat plate member, 303... Front surface, 304... Back surface, 305... Surface opening, 30
6... Back opening, 307... Insulating layer, 308...
Blocking layer, 309...First plating layer, 310...
Second plating layer, 401... Hole, 402... Flat plate member, 403... Surface, 404... Back surface, 405
...Surface opening, 406...Back surface opening, 407...
Insulating layer, 408...blocking layer, 409...first plating layer, 410...second plating layer, 411...
The disk member of the middle chamber is shown.

Claims (1)

[Claims] 1. The electrically conductive flat plate member having micropores formed vertically through the flat plate member and having a cross-sectional area that gradually decreases from the front side to the back side and becomes the minimum at the opening on the back side and in the vicinity thereof. A step of forming a blocking layer to be used as a mold matrix and for isolating the back side of the matrix from the plating solution and blocking the openings on the back surface; a step of forming an insulating layer to prevent the formation of a plating layer; and a step of forming a first plating layer on a required portion of the surface of the mother mold centered around the opening portion of the through hole and on the inner surface of the through hole. , comprising a step of forming a second plating layer on the plating layer, and a step of peeling off the plating layer, the metal having at least a weaker adhesive force to the matrix than the second plating layer. A method for manufacturing an inkjet recording nozzle, characterized in that the layer is the first plated layer.