JP3178490B2 - Inkjet head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 63-252750 discloses a shear mode type ink jet head and a method of manufacturing the same. This shear mode type ink jet head forms an ink flow path separated from each other by a pressure partition by cutting or the like on a piezoelectric ceramic substrate such as PZT, and a nozzle for discharging ink to a part of the ink flow path. Is formed, an electrode is formed on the wall surface of the ink flow path, and a voltage is applied to the electrode to deform the partition wall in a shearing mode to discharge ink from the nozzle. In the inkjet head, an LSI chip, which is a drive circuit for controlling ink ejection, is mounted on a flow path substrate on which an ink flow path is formed.

[0003]

The above-mentioned conventional ink jet head has a problem in the arrangement of the driving circuits.

A wiring pattern is required to mount a drive circuit on a flow path substrate made of a piezoelectric material and to connect the electrodes formed on the flow path partition walls. There are two methods of forming a wiring pattern on a flow path substrate. One is a method of forming a wiring pattern on a piezoelectric material substrate such as PZT and then forming an ink flow path by machining, and the other is a method of forming an ink flow path on a substrate. This is a method of forming a wiring pattern after forming a flow path. However, both had problems.

In the former method of forming an ink flow path on a substrate on which a wiring pattern is formed, it is difficult to accurately adjust the position when the ink flow path is cut with a dicing saw or the like in accordance with the wiring. In addition, there is a high possibility that the wiring pattern will be damaged when the ink flow path is cut, causing a defect such as disconnection.

In the latter method of forming a wiring pattern on an uneven substrate having a flow path, it is difficult to apply a photoresist with a uniform thickness.

Further, a piezoelectric material such as PZT is expensive, and the cost cannot be reduced unless the substrate area is reduced. However, when a driving circuit and its wiring pattern are mounted on a piezoelectric substrate as in the above-described conventional case, the substrate area becomes considerably large. The problem is that the cost increases.

An object of the present invention is to provide a shear mode ink jet head which is small in size, low in cost and easy to manufacture.

[0009]

[MEANS FOR SOLVING THE PROBLEMS] To solve such a problem.
In the present invention , in order to be separated by a pressure partition made of a piezoelectric material , and extended to the surface from each pressure partition to the outside
A head substrate in which a plurality of grooves having exposed electrodes are formed, and an ink flow path formed by sealing the grooves in the head substrate
And expose the electrodes on the surface of the head substrate.
Consisting of arranged cover plate to the ink jet head, said head cover, said on its surface
Control circuit for supplying a drive signal to the electrodes, and a connecting means for connecting the electrode and exposed 及 beauty the control circuit on the surface of the head substrate.

[0010]

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of an ink jet head according to the present invention. In the figure, reference numeral 11 denotes a head substrate made of a piezoelectric material such as PZT and having a thickness of about 0.5 to 2 mm.
An ink channel 12 and a nozzle 13 are formed. An electrode 14 is provided on a wall surface of the ink flow path 12, and the electrode 14 can be electrically connected to the outside of the ink flow path 12 by a lead wire 15. 16 is an ink channel 12
The cover plate is overlaid on the head substrate 11 so as to cover the head substrate 11 and is made of ceramic, glass, plastic, a material used as a printed circuit board, or the like, and has a thickness of 0.5
About 2 mm. A control circuit (L) for controlling the ejection of ink from the nozzles 13 is provided on the cover plate 16.
SI chip) 17 and the control circuit 1
7 are provided. The ink flow path 12 is provided on the cover plate 16 side of the head substrate 11.
And a through hole 2 for connecting the flow path 19 to an ink supply means (not shown).
0 is formed. The lead wire 15 and the lead wire 18 are connected by electrical connection means 21 such as wire bonding.

FIG. 2 shows the head substrate 11 with the cover plate 16 removed. A plurality of ink channels 12 to 12 are formed in the head substrate 11.
Nozzle 13 is formed on the bottom surface of. Lead wires 15 from the ink flow paths 12 adjacent to each other are drawn in opposite directions.

FIG. 3 shows the internal configuration of the control circuit 17. In the figure, reference numeral 31 denotes a temporary storage unit for temporarily storing print information sent from a printer main body (not shown);
32 is a drive circuit for selectively applying a voltage to the electrode 14 based on the print information stored in the temporary storage means 31,
Based on the print information, a voltage is selectively applied to the electrode 14 via the lead wire 18, the electrical connection means 21, and the lead wire 15 to deform the wall surface of the ink flow path 12,
Eject ink from the.

Next, a method of manufacturing the ink jet head shown in FIG. 1 will be described.

First, a method for manufacturing the head substrate 11 will be described.

First, a deep groove serving as the ink flow path 12 and a lead wire 15 are formed on the head substrate 11 by a dicing saw or the like.
A plurality of shallow trenches for forming a trench are formed. For example, a deep groove has a depth of about 400 μm, a width of about 90 μm, and a length of about 15 mm, and a shallow groove has a depth of about 10 μm, a width of about 90 μm, and a length of about 2 mm.

Next, the nozzle 13 is formed. This is YA
It can be formed on the bottom surface of the ink flow path 12 by irradiation with a G laser or an excimer laser such as F2, ArF, KrF, XeCl, XeF or the like.

Next, the electrode 14 is provided on the wall of the ink flow path 12.
Is provided. In this method, Al, Ni, Cr or the like is formed to a thickness of about 1 μm by a vacuum evaporation method or the like from an oblique direction. Further, a protective insulating layer is formed as necessary. Thereafter, the surface of the head substrate 11 is polished to separate the electrodes and the wires.

Thus, the head substrate 1 shown in FIG.
1 is completed.

Next, a method of manufacturing the cover plate 16 will be described.

First, the flow path 19 is formed by mechanical cutting, etching or the like.

Next, the lead wires 18 are formed. In this method, a metal such as Al, Ni, Cr, and Cu is patterned by photolithography to a thickness of about 0.1 to 1 μm. At this time, the surface of the cover plate 16 is flat and the photoresist can be easily applied to a uniform thickness, so that the cover plate 16 can be formed accurately.

Next, a through hole 20 for connecting to the ink supply means is formed by using a drill or the like.

Next, the control circuit 17 is die-bonded and connected to the lead wire 18 by wire bonding or the like.

If necessary, a pipe or the like connecting the ink supply means to the through hole 20 is bonded.

Thus, the cover plate 16 is completed.

Next, to bond the head substrate 11 and the cover plate 16, to connect the lead wire 15 and the lead wire 18 by electrical connection means 21, such as Waiyabon de Ingu. Thus, the ink jet head shown in FIG. 1 is completed.

In the above-described embodiment, the nozzle 13 is provided on the bottom surface of the ink flow path 12, but the present invention is not limited to this. For example, the nozzle 13 may be provided on the cover plate 16.

[0030]

According to the present invention, since the control circuit for controlling the ejection of ink is mounted on the cover portion superposed on the head substrate so as to cover the ink flow path, the head can be miniaturized and the drive circuit and the ink The configuration of the connection portion with the electrode in the flow path can be simplified, and a low-cost, compact, and highly reliable inkjet head can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an inkjet head according to the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a main part of an inkjet head according to the present invention.

FIG. 3 is an explanatory diagram showing a configuration of a main part of an inkjet head according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Head board 12 Ink flow path 13 Nozzle 14 Electrode 15 Lead wire 16 Cover plate 17 Control circuit 18 Lead wire 21 Electrical connection means

Claims (2)

(57) [Claims] 1. A head substrate having a plurality of grooves formed with a plurality of grooves which are separated by pressure partitions made of a piezoelectric material and have electrodes extending to the surface from each pressure partition and exposed to the outside, and sealing the grooves of the head substrate. A cover plate arranged to stop and form an ink flow path, and to expose an electrode on the surface of the head substrate, wherein the cover plate supplies a drive signal to the electrode on the surface thereof. An ink jet head comprising: a control circuit for connecting the control circuit; and connection means for connecting the control circuit and the electrode exposed on the surface of the head substrate. 2. The ink jet head according to claim 1, wherein a nozzle is formed on a bottom surface of the groove of the head substrate.