JP2002210986A - Method for manufacturing ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that alignment is shifted every time when electroforming is performed to cause a trouble, e.g. residue of resist, clogging with ink, variation of ink ejection characteristics, or the like. SOLUTION: Resist patterns 21 and 22 of communication holes 18 and reservoirs 6 are formed on a substrate 19 rendered conductive and a first electroforming layer 23 of 200 μm thick is formed. Subsequently, a resist pattern 24 of pressure chambers 4, ink supply paths 5 and reservoirs 6 is formed and followed by formation of a second electroforming layer 25 of 80 μm thick. Finally, the resist patterns 21, 22 and 24 are stripped and an electroforming spacer 3 is stripped from the substrate 19 rendered conductive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a head for an ink jet printer.

[0002]

2. Description of the Related Art As output devices for computers, printers are required to have higher speed and higher image quality, and ink jet printers are no exception. For this reason, the inkjet head has been improved in function such as reduction of the nozzle pitch and increase in the number of nozzles, and the materials used are various, such as silicon, metal, plastic, photosensitive resin, and glass.

Among the methods using metal, there is a technique of manufacturing by electroforming using a photoresist.
It is described in JP-A-11-105283 and the like.

[0004]

However, the prior art has the following problems.

In a conventional electroforming process using a resist including a dry film, there is a problem that when a pattern finer than the thickness of the electroformed layer is formed, it is necessary to repeat the patterning of the resist and the electroforming process. .

FIG. 13 is a cross-sectional view when a conventional photoresist pattern is formed. When a resist pattern 31 is formed on the surface of the substrate 30 and the resist thickness T, the resist width Wr, and the space width Ws are measured, T / W
Neither r nor T / Ws becomes larger than 1. Therefore, the thickness of the electroformed layer that can be formed by one electroforming process is equal to or less than the pattern width. Ink-jet head spacers have a small pattern size to improve nozzle density, but require a considerable thickness to make the head rigid, and in the prior art, resist pattern formation and electroforming must be repeated. No.

Although there are resists having T / Wr and T / Ws larger than 1, a part having a thickness of several tens to several hundreds of microns is manufactured by electroforming because the thickness of the resist is very thin, about 1 micron. You couldn't use it if you did.

Further, since the resist pattern formation and the electroforming process are repeated many times, there is a problem that irregularities are generated on the side walls. The resist is likely to remain in the concave portion caused by the misalignment, and is likely to dissolve into the ink after assembling the inkjet head and adversely affect the print performance of the head.

In particular, when a dry film of a weak alkali development type is used, the dry film is made of a stripper (3% N
(aOH aqueous solution), it is easy to be caught on a stepped portion, which causes a problem of remaining resist.

Also, due to the misalignment, irregularities also occur on the side walls of the ink supply path for introducing ink from the reservoir into the pressure chambers as shown in FIG. 14, thereby changing the flow path resistance and affecting the ink discharge characteristics. was there.

An object of the present invention is to solve these problems, and an object of the present invention is to provide an efficient method of manufacturing an ink jet head with a high yield.

[0012]

According to the method of manufacturing an ink jet head of the present invention, a nozzle plate having a through hole serving as a nozzle, a groove or a through hole serving as a pressure generating chamber, an ink supply path, and a common ink chamber are provided. And a diaphragm, and a diaphragm, a method for manufacturing an ink-jet head including a flow path unit comprising a resist pattern, wherein the spacer is formed by an electroforming method using a resist pattern as a mold. The resist pattern is formed such that a value obtained by dividing a thickness by a width of the resist pattern is 1 or more.

A nozzle plate having a through hole serving as a nozzle, a pressure generating chamber, an ink supply path, a spacer having a groove or a through hole serving as a common ink chamber, and a diaphragm are provided. A method of manufacturing an ink jet head including a flow path unit, wherein the spacer is formed by an electroforming method using a resist pattern as a mold, and dividing a thickness of the resist pattern by a width between the resist patterns. The resist pattern is formed so that the value obtained is 1 or more.

A nozzle plate having a through-hole serving as a nozzle, a pressure generating chamber, an ink supply path, a spacer having a groove or a through-hole serving as a common ink chamber, and a diaphragm are provided. A method of manufacturing an ink jet head including a flow path unit, wherein the spacer is formed by an electroforming method using a resist pattern as a mold, and 1) a value obtained by dividing a thickness of the resist pattern by a width of the resist pattern. 2) a value obtained by dividing the thickness of the resist pattern by the width between the resist patterns is 1 or more;
A method for manufacturing an ink jet head, wherein the resist pattern is formed so that the above two conditions are satisfied simultaneously.

According to these manufacturing methods, an effect is obtained that a structure having a size smaller than the thickness of the electroformed layer can be formed by one electroforming operation. In addition, since it is not necessary to repeat the electroforming operation, it is possible to eliminate irregularities on the side wall, and to prevent the remaining resist from being eluted or falling off, thereby preventing the inkjet head from being degraded in reliability. At the same time, it is possible to obtain the effect that the remaining resist is prevented, the yield of the manufacturing process is improved, and the manufacturing can be performed efficiently.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments.

(Embodiment) FIG. 1 is an assembled perspective view of an ink jet head of the present invention, and FIG. 2 is a sectional view of the ink jet head of the present invention.

Nozzle row 2 in which many nozzles 2-1 are arranged
And a groove serving as a communication hole 18 for sending ink from the pressure generation chamber 4 and the ink supply path 5 to the reservoir 6 and the pressure generation chamber 4 serving as a common ink chamber to the nozzle 2-1. The flow path unit is composed of three components, the spacer 3 having the through hole formed therein and the diaphragm 7 having the island portion 9 formed therein.

The stretched plate 7 is made of a stretched polymer film, and the island 9 is formed in the center region of the pressure generation chamber 4 in the width direction so as to be long in the longitudinal direction of the pressure generation chamber 4. Through the island portion 9, a displacement by a piezoelectric vibrator 11, which will be described later, is received.

A plurality of piezoelectric vibrators 1 having a longitudinal vibration mode
Vibrator unit 1 configured by fixing the fixing unit 1 to the fixing plate 12
0 is a transducer unit accommodation hole 14 formed in the base 13.
And fixed to the base 13 via the fixing plate 12 with its tip positioned so as to contact the island portion 9.

The base 13 is provided with an ink supply pipe 15 connected to an ink tank.
Is connected to a reservoir 6 constituted by the spacer 3 through an ink supply port 8 opened to the outside. The channel unit constituted by the nozzle plate 1, the spacer 3, and the diaphragm 7 is attached to the base 13 by the frame 16.
, And the entire head is fixed to the carriage via the substrate 17.

Next, the structure of the spacer 3 will be described with reference to the drawings.

FIG. 3 is a plan view of the spacer and a cross-sectional view taken along line AA '. The dimensions a to f in the figure are as shown in Table 1. The thickness d or e of each electroformed layer is a, b,
The value divided by the dimensions of c and f is greater than 1 as shown in Table 2,
The spacer 3 is a structure having a size smaller than the thickness of the electroformed layer.

[0024]

[Table 1]

[0025]

[Table 2]

Next, a method of manufacturing the spacer 3 will be described with reference to the drawings. 4 to 9 show the manufacturing steps of the spacer 3 in order.

First, a resist capable of forming a pattern having a size smaller than the film thickness is coated on the surface of the conductive processing substrate 19, and is exposed and developed to form a resist pattern 21 of the communication hole 18 and the reservoir 6 of the first layer. A resist pattern 22 is formed (FIG. 4).

Here, the diameter of the resist pattern 21 is 1
00 microns, and the thickness of the resist patterns 21 and 22 is 200 microns.

Next, a thickness of 2
A first electroformed layer 23 of 00 micron is formed (FIG. 5), and a resist pattern 24 of the pressure chamber 4, the ink supply path 5, and the reservoir 6 is formed (FIG. 6).

Here, the thickness of the resist pattern 24 is 8
0 microns.

Subsequently, a second electroformed layer 25 having a thickness of 80 μm is formed by a second nickel electroforming process (FIG. 7). Next, the resist patterns 21, 22, and 24 are stripped (FIG. 8), and the spacer 3 having an electroformed structure is stripped from the conductive processing substrate 19 (FIG. 9).

In the present embodiment, the surface of the silicon substrate for semiconductor as the conductive treatment substrate 19 is made of chromium / silicon.
Although a copper conductive film is used, any material may be used as long as the spacer 3 formed by electroforming can be separated from the substrate. For example, chromium / nickel, aluminum, titanium / copper, titanium /
A conductive film formed of nickel, a titanium-tungsten alloy, or the like may be formed, or a conductive film formed of the above-described conductive film on a resin substrate such as polycarbonate may be used.

In this embodiment, NANO XP is used as a resist capable of forming a pattern having a dimension smaller than the film thickness.
SU-8 (Microlithography, USA)
Chemical Corporation) was used, but any type of resist from any manufacturer may be used as long as the resist can form a pattern having a dimension smaller than the film thickness.

(Comparative Example) For comparison with the example, a spacer having the structure shown in FIG. 3 was experimentally manufactured using a weak alkali developing type dry film. FIGS. 10 to 12 show steps of manufacturing the spacer 3 using a dry film in order.

First, the electroforming pattern 26 of a dry film having a thickness of 50 μm and the electroforming process of nickel are repeated four times on the surface of the conductive processing substrate 19, and the first to fourth layers are formed.
The electroformed layer 27 up to the layer is formed (FIG. 10). Then thickness 2
The formation of an electroformed pattern 28 of a 5-micron dry film and the electroforming process of nickel are repeated four times to form the fifth to eighth electroformed layers 29 (FIG. 11). Thereafter, the electroformed patterns 26 and 28 of the dry film are peeled off using a 3% aqueous solution of sodium hydroxide, and
The electroformed structure is peeled off from FIG. The ink supply path of the spacer manufactured according to this comparative example has a cross-sectional shape as shown in FIG. 14, and the sidewall has irregularities.

Table 3 shows a comparison of the defect occurrence rate between the embodiment and the comparative example.

[0037]

[Table 3]

First, the rate of occurrence of defective resist remaining in the resist peeling step after the electroforming treatment is lower in the example. The main cause of the resist residue generated in the comparative example was that the dry film was not able to be removed because the dry film was sandwiched between the steps on the side wall.

Next, a comparison of print defects occurring in the print inspection after head assembly showed that almost no defect occurred in the example, but several percent occurred in the comparative example. A detailed investigation of the defects that occurred in the print inspection revealed the following two phenomena.

One was a phenomenon in which a piece of resist that could not be removed by peeling off the resist clogged the nozzle, and could discharge only a part of the ink or not at all.

The other is a phenomenon in which the flow path resistance changes due to the ink supply path having the shape as shown in FIG. 14, and characteristics such as the ink discharge speed and the discharge weight are out of the standard.

[Brief description of the drawings]

FIG. 1 is an assembled perspective view of an inkjet head according to the present invention.

FIG. 2 is a cross-sectional view of the ink jet head of the present invention.

FIG. 3 is a plan view and a cross-sectional view of a spacer of the inkjet head.

FIG. 4 is a perspective view after a first-layer resist pattern is formed in the embodiment of the present invention.

FIG. 5 is a perspective view after forming a first electroformed layer in the embodiment of the present invention.

FIG. 6 is a perspective view after forming a second-layer resist pattern in the embodiment of the present invention.

FIG. 7 is a perspective view after a second electroformed layer is formed in the embodiment of the present invention.

FIG. 8 is a perspective view after a resist is stripped in the embodiment of the present invention.

FIG. 9 is a perspective view after an electroformed layer is peeled off from a conductive processing substrate in the example of the present invention.

FIG. 10 is a perspective view of a comparative example after repeating formation of a dry film pattern and electroforming from a first layer to a fourth layer.

FIG. 11 is a perspective view of a comparative example after the formation of a dry film pattern from a fifth layer to an eighth layer and electroforming are repeated.

FIG. 12 is a perspective view of a comparative example after an electroformed layer has been peeled off from a conductive treatment plate.

FIG. 13 is a cross-sectional view when a pattern is formed by a conventional resist.

FIG. 14 is a cross-sectional shape when resist pattern formation and electroforming are repeated.

[Description of Signs] 1 Nozzle plate 2 Nozzle row 2-1 Nozzle 3 Spacer 4 Pressure generating chamber 5 Ink supply path 6 Reservoir 7 Vibration plate 8 Ink supply port 9 Island portion 10 Vibrator unit 11 Piezoelectric vibrator 12 Fixing plate 13 Table 14 Oscillator unit accommodation hole 15 Ink supply pipe 16 Frame 17 Substrate 18 Communication hole 19 Conductive treatment substrate 21 Resist pattern of communication hole 22 Resist pattern of reservoir 23 First electroformed layer 24 Pressure chamber, ink supply path And reservoir resist pattern 25 second electroformed layer 26 first to fourth layer dry film pattern 27 first to fourth layer electroformed layer 28 fifth to eighth layer dry film pattern 29 Five to eighth electroformed layers 30 Substrate 31 Photoresist pattern

Claims (3)

[Claims] 1. A nozzle plate having a through hole serving as a nozzle, a pressure generating chamber, an ink supply path, a spacer having a groove or a through hole serving as a common ink chamber, and a diaphragm. A method of manufacturing an ink jet head including a flow path unit, wherein the spacer is formed by an electroforming method using a resist pattern as a mold, and a value obtained by dividing a thickness of the resist pattern by a width of the resist pattern is 1 A method for manufacturing an ink jet head, comprising forming the resist pattern as described above. 2. A nozzle plate having a through hole serving as a nozzle, a pressure generating chamber, an ink supply path, a spacer having a groove or through hole serving as a common ink chamber, and a diaphragm. A method of manufacturing an ink jet head including a flow path unit, wherein the spacer is formed by an electroforming method using a resist pattern as a mold, and dividing a thickness of the resist pattern by a width between the resist patterns. Wherein the resist pattern is formed such that the value obtained is 1 or more. 3. A nozzle plate having a through-hole serving as a nozzle, a pressure generating chamber, an ink supply path, a spacer having a groove or through-hole serving as a common ink chamber, and a diaphragm. A method of manufacturing an ink jet head including a flow path unit, wherein the spacer is formed by an electroforming method using a resist pattern as a mold, and 1) a value obtained by dividing a thickness of the resist pattern by a width of the resist pattern. 2) The value obtained by dividing the thickness of the resist pattern by the width between the resist patterns is 1 or more. The resist pattern is formed so that the above two conditions are satisfied simultaneously. A method of manufacturing an ink jet head.