JPH02188254A - Discharge port plate and ink jet recording head having same discharge port plate - Google Patents

Abstract

PURPOSE:To prevent a failure in forming a through hole, the deformation of the hole, or the breakage of a punch itself by using a planar material having specific physical properties for forming a discharge port plate. CONSTITUTION:As a planar material for forming a discharge port plate, a material made of a resin having hardness of M50 or more and a flexural modulus of 100kg/mm<2> or more is used. All the resin materials having the aforesaid values of physical properties and meeting required characteristics in a state of being incorporated in an ink jet recording head can be used without limitation. As the resin, polyether etherketone, polyether sulfone, polyimide, and the like can be exemplified as a preferable material. In addition, a discharge port is preferably formed on the planar material using a punch and a die with a relation t/d<=2.5, where (d) is a diameter of the punch and (t) is a thickness of the planar material.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a method for forming through holes for forming ejection ports of an ejection port plate used in manufacturing an inkjet recording head.
The present invention relates to an ejection port plate made of a material suitable for forming holes by press working, and an inkjet recording head having the ejection port plate.

[Prior Art] Recording using the inkjet recording method is performed by ejecting small droplets of recording ink from the ejection openings of a recording head.

An overview of the inkjet recording head will be explained with reference to FIG.

1 is a chip dunk into which ink flows from an ink tank (not shown); 2 is a back cover of the chip tank 1;

3 is a grooved top plate, and 4 is a heater board. A plurality of grooves are provided in parallel on the grooved top plate 3, and the grooves and the heater board form a liquid path through which the ink flows.

The heater board is provided with an energy generator that generates thermal energy for ejecting ink droplets.

5 is a discharge port plate having the same number of micro holes (through holes) 5a corresponding to the plurality of grooves;
It is attached to the surface 1a. The diameter of micropores is usually 20-5
0JJj. The ink flows through the filter 6 into the ink channel formed by the grooved top plate 3 and the heater board 4. The liquid is ejected from the opening (ejection port) in the form of droplets.

The fine holes 5a of the discharge port plate 5 are formed, for example, by press working.

As shown in FIG. 2, the press working is performed by supplying the plate member 6 between the punch 10 and the die 11, and lowering the punch 10 at high speed by a drive device (not shown).

Further, the plate member 6 is intermittently fed by a device not shown,
Multiple micro holes are drilled at the same pitch.

Conventionally, a metal plate has been mainly used as a material for the discharge port plate formed by such press working.

In addition to press working, electroforming was also used to form holes by electrolytic plating.

[Problem to be Solved by the Invention J] However, as shown in the above-mentioned conventional example, when a metal plate member as a material for the discharge port plate is processed using a normal press machine, the thickness of the plate member and the diameter of the micropores are Depending on the
Processing problems may occur, such as the hole not penetrating, the hole being deformed, or the punch itself being damaged.

The present inventors investigated the problems in press working and found that when t/d≧0.8, where the thickness of the plate member is t and the diameter of the micropore is d, the above problem occurs. We have learned that there are cases where problems may be more likely to occur.

Furthermore, if t/d<0.8, the above problem is relatively unlikely to occur, but when trying to satisfy this relationship, the diameter of the micropore for forming the discharge port is usually 20 to 50μ. Since it is quite small, the thickness of the plate member must also be made quite thin, 16 to 40 mm or less. In the case of such thin plate members, precision is required in the molding of the plate member, and there is a high possibility that the outlet plate will break during transportation, which can cause problems such as difficulty in handling. .

Furthermore, when forming by electroforming, plating is used, which may increase the cost of the discharge port plate.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ejection orifice plate that can solve the problems of conventional ejection orifice plates as described above, and an inkjet recording head having the ejection orifice plate.

[Means for Solving the Problems] The discharge port plate of the present invention uses a resin having a hardness of M50 or more and a bending elastic modulus of xookg/mm" or more for the plate member as its forming material. It is characterized by being present.

The resin material can be used without any restriction as long as it has the above-mentioned physical properties and satisfies the desired characteristics when incorporated into an inkjet recording head.

Examples of the resin include polyetheretherketone,
Suitable examples include polyether sulfone and polyimide.

The ejection port plate of the present invention is incorporated into a recording head main body provided with an energy generator that generates energy, such as thermal energy, used for ejecting ink to constitute the ejection port. A recording head can be manufactured.

In addition, "hardness" in the present invention refers to the standard load Wl of Rockwell hardness of 10 kg and the test load W of 10 kg.
The measurement was carried out using an M scale with a steel ball diameter of 6.35±0.0025 mm.

First, a standard load W is pressed into the test surface using a steel ball as an indenter, and a constant load (Wa - W+) is further applied to make the test load W2. After that, when the standard load W1 was returned again, the difference h (mm) between the depths of the dents at the two times before and after the standard load was measured.

Rockwell hardness is calculated by H, I = 130-500h.

Furthermore, the "flexural modulus" was measured using a three-point bending method in which a concentrated load was applied to the center of a beam simply supported by two fulcrums.

The flexural modulus is obtained from the following formula.

Bending elastic modulus = (W/y)L3/4bh' However, W:
Load at failure (kg), (W/y): The slope of the initial rising straight line, the load at unit deflection of the test piece (kg/y)
mm), b: Width of the test piece (10 ± 0, 5 mm), h: Height of the test piece (4 ± 0.2 mm), L: Distance between fulcrums (16
h±0.5mm).

Note that both hardness and flexural modulus could not be measured using thin pieces, so they were measured using block-shaped test pieces.

[Example] Examples of the present invention will be described below.

As plastic materials for forming the discharge port plate, (1) polyetheretherketone (PEEK) (2)
Polyethersulfone (PES) (3) Polyimide (P
I) (4) Polyethylene (PE) (5) Dry film (DF, photosensitive resin) is given as an example.

For reference, (6) metal plate is also taken as an example.

The hardness and shear force (flexural modulus) of the materials (1) to (5) above, measured by the above-mentioned method, were as follows, respectively.

Hardness Modulus of elasticity (kg/mm”) (1) PEEK material M2O250 (2) PES material M2S 240 (3) PI material MIOo 260 (4) PE material M2O7
0 (5) DF material M2O40 or less Next, plate members made of these materials (10mmX4n+
Using a press machine (m), fine holes for forming discharge ports were punched in each plate member using a punch and die as shown in FIG. 2, and the conditions shown in Table 1 were obtained.

However, the diameter of the punch is d2, and the thickness of the plate member is t.

From Table 1, at t/d>2.5, the above (1) to (3)
In the case of a plate member made of this material, there were cases where a break 20 and a sag 21 as shown in FIG. 3 were generated.

However, if t/d≦2.5, (1) PEE
In the K material, (2) PES material, and (3) PI material, no cracks or sagging occurred, and the surface accuracy was very good.

Table positive: When the hole penetrates without deformation and the height of the hole is 10% or less of the wall thickness [Effects of the invention] As explained above, in the present invention, the formation of the discharge port plate is By using a plate member made of a plastic material with specific physical properties and forming fine holes for forming the discharge port by press working, the rigidity of the discharge port plate prevents the holes from penetrating or is no longer deformed or the punch itself is damaged.

Further, in the discharge port plate of the present invention, t/d≦2.5(
Within the range of (t: thickness of the discharge port plate, d: diameter of the discharge port), the surface precision of the discharge port plate was significantly improved without causing any cracks or sag.

That is, since the discharge port plate of the present invention can be formed with high precision within the range of t/d≦2.5, the diameter d of the discharge port can be set to 20
Even when the thickness is ~50μ, the thickness t of the discharge port plate is 5
Even if the thickness is increased to about 0 to 125 μm, good press working can be performed. Therefore, the main body (plate member) is easy to mold, and it is also easy to handle, so it does not bend or bend.
It can be transported, assembled, etc. reliably without being damaged.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of an inkjet recording head using an ejection port plate, Fig. 2 is a diagram illustrating the press working of the ejection port plate, and Fig. 3 is a diagram showing the cracks and cutouts that occur when the ejection port plate is pressed. It is a diagram showing an example of sagging. 1: Chip tank 2: Back cover 3: Grooved top plate 4: Heater board 5: Discharge port plate 5a: Discharge port 6 Ni filter 1O: Punch 11: Die 20: Paris 21: Punching sag

Claims (1)

[Scope of Claims] 1) An ejection port plate made of a plate member provided with through holes for forming ejection ports of an inkjet recording head, wherein the plate member has a hardness of M50 or more and a weight of 100 kg.
A discharge port plate characterized in that it is formed using a resin material having an elastic modulus of /mm^2 or more. 2) The outlet plate according to claim 1, wherein the resin material is selected from polyetheretherketone, polyethersulfone, and polyimide. 3) The discharge port plate according to claim 1 or 2, wherein t/d≦2.5, where t is the thickness of the discharge port plate and d is the diameter of the discharge port. 4) An inkjet recording head comprising the ejection port plate according to any one of claims 1 to 3.