JP2861117B2 - Ink jet printer head and method of manufacturing the same - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an ink jet printer head.

[Prior Art] Among the conventional ink jet printer heads, there is a so-called on-demand type ink jet printer head which deforms a liquid flow path by a piezoelectric element or the like and discharges ink droplets, as shown in FIG. This is a substrate 10 having grooves and through holes formed therein to form ink droplets.
The liquid flow path 12 is obtained by joining the substrate and the flat substrate 7, and a compressive force is applied to the liquid flow path by the piezoelectric element 8 or the like, and the liquid droplet is discharged from the end of the liquid flow path. Since the substrate 10 in which the groove and the through hole are formed is a plastic substrate manufactured by injection molding, there is a limit to reducing the diameter of the through hole. In order to obtain high-definition printing, a metal orifice plate 11 having micropores with a diameter of about several tens of μm is joined to the end of the liquid flow path, thereby reducing the diameter of the ink droplets to several tens of μm and printing high definition Was possible.

[Problems and Object to be Solved by the Invention] However, the above-described conventional technology has the following problems. Since the above-mentioned metal orifice plate 11 is usually manufactured by electroforming or etching, that is, manufactured in a process separate from the substrate 10, the cost naturally increases. Although the metal orifice plate is bonded to the substrate 10, it is difficult to bond the metal and the plastic, and in some cases, the metal orifice plate may be decomposed, resulting in low reliability. Also, due to the difference between the hole pitch of the orifice plate and the pitch of the through holes formed in the substrate,
The flight path of the ink droplets fluctuated, and the print quality was degraded. The present invention solves such a problem, and an object of the present invention is to provide an ink jet printer head having excellent reliability and printing quality at a low cost.

[Means for Solving the Problems] An ink jet printer head of the present invention includes a through-hole in which a groove having a rectangular cross section serving as a flow path for applying a compressive force to cause droplets to be discharged from a discharge port serves as a discharge port. A silicon substrate formed as described above, a flat plate serving as a vibrating plate, and vibration generating means such as a piezoelectric element disposed via the flat plate and corresponding to the groove.

Further, the method for manufacturing an ink jet printer head of the present invention is a method for manufacturing an ink jet printer head for manufacturing such an ink jet printer head, wherein the crystal axis direction is <100> or <110>. A first step of forming a Si oxide film on both surfaces; a second step of forming a first opening in the Si oxide film;
A third step of performing anisotropic etching using an alkaline liquid until the silicon oxide film penetrates the Si substrate through the opening, and forming a through hole serving as a discharge port in the Si substrate; A fourth step of forming a second opening so as to cover the through hole, and the second opening through the second opening.
Performing anisotropic etching using an alkaline liquid to a predetermined depth of the Si substrate, forming a groove having a rectangular cross section serving as a flow path for applying a compressive force to discharge droplets from the discharge port in the Si substrate. And step 5 in this order.

[Example] Hereinafter, an example of the present invention will be described in detail. FIG. 1 shows a processing step diagram of the Si plate. As the Si plate, a Si substrate having a crystal axis direction of <100> and a thickness of 220 μm was used. The so-called thermal oxide film 2 was obtained by heating the Si plate 1 in an oxygen atmosphere (FIG. 1A). In order to use the thermal oxide film 2 as an etching mask, patterning corresponding to the through hole was performed (FIG. 1B). In this embodiment, a square pattern having a side of 360 μm is used. Next, etching was performed with an ethylenediamine-based alkali etching solution until the Si plate was penetrated (FIG. 1 (c)). In the etching of a Si single crystal with an alkali, the etching rate is significantly different depending on the crystal axis direction, that is, the etching rate is significantly lower in <111> than in <100> or <110>, and the above-described etching is anisotropic etching. The cross-sectional shape of the through hole has a trapezoidal shape such that the slope is a <111> plane as shown in FIG.
Since the shape is uniquely determined by the length of the opening (non-masking portion) and the etching depth (thickness of the Si plate), the shape variation is so small that it can be ignored. The opening on the bottom surface side of the through hole had a square shape with a side of 50 μm. Next, the thermal oxide film is removed from the portion corresponding to the groove serving as the liquid flow path so as to cover the through hole (FIG. 1 (d)), and similarly etched to a predetermined depth with alkali to form the groove. (FIG. 1 (e)). Finally, the substrate 4 was immersed in a hydrofluoric acid-based etching solution to remove the SiO ₂ on the upper surface and the lower surface (the corresponding figure is not shown in FIG. 1). The Si substrate 4 having the through-holes and grooves obtained by the above-described processing steps is adhered to the flat plate 7 as shown in FIG. 2, then the piezoelectric element 8 is stuck on the flat plate 7, and the ink supply pipe 9 is attached. The ink jet printer head is completed. The structure of the ink jet printer head obtained in this way is such that the substrate and the orifice plate in the conventional ink jet printer head are integrated, so that there is no need for a bonding step between the substrate and the orifice plate, and there are also problems such as peeling. Cannot occur. Further, since the size and direction of the through hole are formed uniformly, the size of the ejected ink droplet is uniform, and the flight path is perpendicular to the substrate and does not bend, thereby improving the printing quality. Although the case where the crystal axis is <100> has been described above, an ink jet printer head can be basically formed similarly in the case of a <110> Si substrate, and the same performance can be exhibited.

[Effects of the Invention] As described above, the ink jet printer head of the present invention has a through-hole in which a rectangular cross-sectional groove serving as a flow path for applying a compressive force to cause droplets to be ejected from an ejection port serves as an ejection port. Si substrate formed so as to include, a flat plate serving as a vibration plate, and vibration generating means such as a piezoelectric element disposed via the flat plate and corresponding to the groove, characterized by comprising I do.

For this reason, according to the inkjet printer head of the present invention, since the groove having a rectangular cross section is formed so as to include the through hole serving as the discharge port, the resistance as the ink flow path is low and the ink is supplied smoothly. be able to. Moreover, since the rectangular cross-sectional groove serves as a flow path for applying a compressive force to discharge the droplet from the discharge port, and a piezoelectric element or the like is arranged corresponding to the rectangular cross-sectional groove,
The compression force can be generated efficiently, and as a result, ink can be ejected efficiently.

The method for manufacturing an ink jet printer head of the present invention is a method for manufacturing an ink jet printer head for manufacturing an ink jet printer head as described above, wherein both sides of a Si substrate whose crystal axis direction is <100> or <110>. A first step of forming a first opening in the Si oxide film, a second step of forming a first opening in the Si oxide film, and a step of penetrating the Si substrate through the first opening. A third step of performing anisotropic etching using an alkali solution to form a through hole serving as a discharge port in the Si substrate, and a second step of including the through hole in the Si oxide film. A fourth step of forming an opening, and anisotropic etching using an alkaline solution is performed to a predetermined depth of the Si substrate through the second opening to apply a compressive force to discharge the droplet. Cross section serving as a flow path for discharging from the outlet And having a fifth step of forming a square groove in the Si substrate, the in this order.

Therefore, according to the method of manufacturing an ink jet printer head of the present invention, the ink jet printer head of the present invention having the above-described excellent effects can be efficiently manufactured.

[Brief description of the drawings]

FIG. 1 is a process diagram of a Si plate according to the present invention. FIG. 2 is a configuration diagram of an ink jet printer head according to the present invention. FIG. 3 is a diagram of a conventional ink jet printer head. FIG. 4 is a sectional view of FIG. FIG. 5 is a sectional view of FIG. 1 ... Si plate 2 ...... SiO ₂ film 3 ...... <111> plane 4 ...... groove and the through hole is formed Si substrate 5 ... through hole 6 ... groove 7 ...... flat 8 ...... piezoelectric element 9 …… Ink supply pipe 10 …… Plastic substrate with grooves and through holes formed 11 …… Metal orifice plate 12 …… Liquid flow path

Claims (2)

(57) [Claims] An Si substrate having a groove having a rectangular cross section serving as a flow path for applying a compressive force to cause a droplet to be ejected from an ejection port is formed so as to include a through hole serving as the ejection port. An ink jet printer head, comprising: a flat plate serving as a plate; and vibration generating means such as a piezoelectric element disposed through the flat plate and corresponding to the groove. 2. A method for manufacturing an ink jet printer head according to claim 1, wherein the crystal axis direction is <100> or <110>.
A first step of forming a Si oxide film; a second step of forming a first opening in the Si oxide film; and a step of penetrating the Si substrate through the first opening. A third step of performing anisotropic etching using an alkaline liquid to form a through hole serving as a discharge port in the Si substrate, and a second opening including the through hole in the Si oxide film. A third step of forming a portion, and performing anisotropic etching using an alkaline solution to a predetermined depth of the Si substrate through the second opening to give a compressive force to discharge the droplet. A fifth step of forming a groove having a rectangular cross section as a flow path for discharging from the Si substrate in the Si substrate in this order.