JPH10250053A - Ink jet device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet device having a simple structure not requiring an expensive FPC (flexible printed circuit) capable of being readily manufactured. SOLUTION: Each of electrodes 15 and each conductive pattern 23 opposite each of the terminal edges thereof are connected with each other by a solder bump 31. When a driving voltage is applied to the electrode 15 via the conductive pattern 23 and solder bump 31, a side wall 17 provided to the electrode 15 is deformed and a pressure vibration is generated in an ink liquid chamber 13 so that ink in the ink liquid chamber 13 is ejected (B). At the manufacturing thereof, the solder bump 31 is provided on the conductive pattern 23 and a base plate 3 is superposed on a cover plate 5. The electrode 15 and conductive pattern 23 are electrically connected with each other via the small spherical solder bump 31 by reflowing (A). As a result, the connection of the electrode 15 with the conductive pattern 23 is readily carried out without using an FPC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ejecting apparatus for ejecting ink from a nozzle in accordance with a driving voltage, and more particularly, to a method in which at least a part of a side wall of an ink liquid chamber is formed as a piezoelectric portion, and ink is ejected by deformation of the piezoelectric portion. The present invention relates to an ink ejecting apparatus.

[0002]

2. Description of the Related Art Heretofore, there has been an ink ejecting apparatus which forms a piezoelectric portion at least a part of a side wall of an ink liquid chamber and ejects ink by deformation thereof.
For example, it is applied to an inkjet head for an inkjet printer.

FIG. 3 is an exploded perspective view showing the structure of an example of a conventional ink jet head. As shown in FIG.
A flat nozzle plate 55 is fixed to the head body 53 of the inkjet head 51 on the side (hereinafter referred to as the front surface) facing the recording paper, and a large number of nozzles 55a are bored in the nozzle plate 55 in two rows. Have been.
The head main body 53 has an ink liquid chamber (not shown) for each nozzle 55a in the inside thereof, and a part of the side wall of the ink liquid chamber is a piezoelectric portion composed of a piezoelectric element or the like. Also, a large number of electrodes 5 for individually applying a voltage to the piezoelectric portion of each ink liquid chamber are provided on the left and right side surfaces of the head body 53.
7 is exposed.

When a drive voltage is applied to the electrode 57, the side wall of the corresponding ink liquid chamber is deformed, and the ink in the ink liquid chamber is ejected from the corresponding nozzle 55a. After the ink is ejected, when the side wall returns to the original shape, ink is supplied from an ink cartridge (not shown) through an ink supply port 59a of a manifold 59 provided at the rear portion of the head main body 53, and the ink again supplies the ink. The ink liquid chamber is filled.

On the other hand, a driver chip 63 for outputting the drive voltage based on control data and the like is provided on the lower surface of the ceramic substrate 61 to which the head main body 53 is fixed. The driver chip 63 is a known element formed by an IC, and outputs the above-described drive voltage to an electrode 67 provided on the upper surface of the ceramic substrate 61. The electrode 67 is an FPC
It is connected to the electrode 57 via a (flexible printed circuit board) 69 so that the drive voltage can be applied to the side wall of the ink liquid chamber.

[0006]

However, in recent years, in order to improve the image quality of an ink jet printer, a nozzle 5 is required.
The arrangement interval of 5a is made dense. For this reason, the electrodes 57 and 67 also need to be provided at a narrow pitch, and the FPC 69 connecting them becomes extremely expensive. In addition, it is difficult to accurately connect the FPC 69 to each of the electrodes 57 and 67.
1 increases the manufacturing cost.

Accordingly, an object of the present invention is to provide an ink ejecting apparatus which has a simple structure which does not require an expensive FPC and which can be easily manufactured.

[0008]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the invention according to claim 1 has a base plate having a groove formed at least in part by a side wall which is a piezoelectric portion; A cover plate that covers the groove to form an ink liquid chamber, an electrode provided on the piezoelectric portion of the side wall, and a nozzle that communicates with the ink liquid chamber; and a drive voltage is applied to the electrode. An ink ejecting apparatus that ejects ink from the nozzles by causing pressure oscillation in the ink liquid chamber by deforming the side wall, and a conductive pattern formed on a surface of the cover plate facing the electrode, A connection portion formed of a substantially small brazing material and electrically connecting the electrode and the conductive pattern facing the electrode is provided.

According to the present invention, the conductive pattern formed on the cover plate is electrically connected to the electrode on the side wall constituting the ink liquid chamber via the connection portion. Therefore, when a driver chip or the like is connected to the conductive pattern and a drive voltage is applied to the conductive pattern, the drive voltage is applied to the electrodes. Then, the side wall on which the electrode is provided is deformed and pressure vibration is generated in the ink liquid chamber, so that the ink in the ink liquid chamber can be ejected from the nozzle.

Here, in the present invention, since the conductive pattern is formed on the cover plate and the conductive pattern is connected to the electrode through the connection portion, the configuration is extremely simplified, and the manufacture becomes easy. That is, the ink ejecting apparatus of the present invention has a simple configuration that does not require an expensive FPC, and can be easily manufactured. Further, when connecting the electrode and the conductive pattern with a brazing material, it is conceivable to provide a brazing material on the entire surface of the electrode or the conductive pattern. However, in the present invention, a substantially small spherical brazing material (for example, When the brazing material is solder, a so-called solder bump is used. For this reason, the electrical connection between both can be reliably ensured by one or more point-like portions.
Therefore, in the ink ejecting apparatus of the present invention, the manufacturing cost can be favorably reduced, and the reliability can be favorably improved.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the electrode and the conductive pattern are disposed with a gap therebetween, and the connection portion is connected to the electrode and the conductive pattern across the gap. It is characterized in that a conductive pattern is connected. According to the present invention, the electrode and the conductive pattern are arranged with a gap therebetween, and the connection portion (substantially small spherical brazing material such as a solder bump) is provided.
Connect the two over the gap. For this reason, the brazing material as the connection portion is securely attached to the electrode and the conductive pattern by the surface tension, and the two can be electrically connected very reliably. In addition, the brazing material does not protrude from between them and adhere to extra portions. Therefore, in the ink ejecting apparatus of the present invention, in addition to the effect of the first aspect of the present invention, there is an effect that the reliability of the apparatus can be further improved.

The invention described in claim 3 is the first or second invention.
In addition to the configuration described above, the cover plate is formed to be longer than the base plate, and the conductive pattern is formed to extend to a portion of the cover plate that does not face the base plate, and the conductive pattern faces the base plate of the cover plate. A driver chip for applying the driving voltage via the conductive pattern is provided in a portion not to be provided.

As described above, according to the present invention, since the driving voltage can be applied from the driver chip provided on the cover plate through the conductive pattern, the connection between the conductive pattern and the driver chip is facilitated, and Will also be simplified. Although the driver chip may generate heat during driving, the present invention can radiate heat via the cover plate. Therefore, the temperature rise of the driver chip can be prevented well. Therefore, in the ink jetting apparatus of the present invention, in addition to the effects of the first and second aspects of the present invention, there is an effect that the manufacturing cost can be further reduced and the reliability thereof can be further improved.

According to a fourth aspect of the present invention, there is provided a base plate having a groove at least partially formed by a side wall which is a piezoelectric portion, a cover plate covering the groove to form an ink liquid chamber, and An electrode provided in the piezoelectric portion, and a nozzle communicating with the ink liquid chamber, wherein a pressure voltage is generated in the ink liquid chamber by applying a driving voltage to the electrode to deform the side wall, and A method of manufacturing an ink ejecting apparatus for ejecting ink from a substrate, comprising: forming a conductive pattern on a surface of the cover plate facing the electrode; and disposing a substantially small spherical brazing material on the conductive pattern facing the electrode. Then, the base plate is overlaid on the cover plate, and the electrode and the conductive pattern are electrically connected by the brazing material.

According to the present invention, a conductive pattern is formed on the surface of the cover plate facing the electrode on the side wall constituting the ink liquid chamber, and a substantially spherical solder is formed on the conductive pattern facing the electrode. A material is provided, and subsequently, the base plate having the side walls and the electrodes is superimposed on the cover plate, and the electrodes and the conductive patterns are electrically connected by the brazing material. Thus, in the present invention, while forming a conductive pattern on the cover plate,
Since the conductive pattern is connected to the electrode via the brazing material, the ink ejecting apparatus can be easily manufactured without using an expensive FPC.

When the electrode and the conductive pattern are connected by a brazing material, a brazing material may be provided on the entire surface of the electrode or the conductive pattern. However, in the present invention, a substantially small spherical brazing material (for example, solder) is used. The electrode and the conductive pattern are connected via a bump). For this reason, the electrical connection between both can be reliably ensured. Therefore, in the present invention,
An ink ejecting apparatus having excellent reliability (the ink ejecting apparatus according to claim 1) can be manufactured very easily, and the manufacturing cost can be reduced favorably.

[0017]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view illustrating a configuration of an ink ejecting apparatus to which the present invention is applied. FIG.
1 shows a case where the present invention is applied to an ink jet head 1 as an ink ejecting apparatus. The ink jet head 1 is mounted on a carriage of an ink jet printer (not shown) and driven as is well known.

As shown in FIG. 1, the ink jet head 1 includes a base plate 3, a cover plate 5, a nozzle plate 7, and a manifold 9. The base plate 3 is formed in a substantially rectangular parallelepiped shape by piezoelectric ceramics, and a plurality of grooves 11 having a rectangular cross section are provided in parallel along the longitudinal direction thereof by cutting or the like. The base plate 3 is polarized in the thickness direction. As shown in FIG.
The ink liquid chamber 13 is constituted by fixing the cover plate 5 from the opposite side.
The electrode 15 is fixed to the side surface of the side wall 17 of 3. The electrode 15 is disposed with a slight gap from the lower end of the side wall 17 (the end on the cover plate 5 side).

Returning to FIG. 1, the cover plate 5 is formed longer than the base plate 3 by a known ceramic substrate. Base plate 3 of cover plate 5
A driver chip 21 composed of a well-known IC is fixed to a portion that does not face the device, and from an output terminal (not shown) of the driver chip 21 to a position facing each electrode 15,
The conductive pattern 23 is formed on the cover plate 5. The nozzle plate 7 has a large number of nozzles 7a.
They are drilled side by side. After fixing the base plate 3 to the cover plate 5, the nozzle plate 7
Is fixed, each nozzle 7a individually communicates with the ink liquid chamber 13. Further, the manifold 9 has an ink supply port 9a to which ink is supplied from an ink cartridge (not shown), and distributes the ink supplied to the ink supply port 9a to each ink liquid chamber 13.

As shown in FIG. 2B, each electrode 15 and the conductive pattern 23 facing the electrode 15 are connected via a solder bump 31. Therefore, the driver chip 21
Outputs a drive voltage, the voltage is applied to the conductive pattern 23.
And applied to the electrode 15 via the solder bump 31.
Then, the side wall 17 on which the electrode 15 is provided is deformed, and pressure vibration occurs in the ink liquid chamber 13, and the ink liquid chamber 13
Can be ejected from the nozzle 7a. When the side wall 17 returns to the original shape after the ejection of the ink, the ink is supplied from the ink cartridge through the ink supply port 9a of the manifold 9, and the ink liquid chamber 13 is filled with the ink again.

The driver chip 21 is connected to a control circuit (not shown) via a clock line, a data line, a voltage line, and a ground line. The driver chip 21 determines from the data appearing on the data line which nozzle 7a should eject ink droplets based on the continuous clock pulse supplied from the clock line, and drives the ink liquid chamber 13 The voltage of the voltage line is applied to the electrode 15 inside.

Next, a method for manufacturing the ink jet head 1 will be described. The base plate 3, the cover plate 5, the nozzle plate 7, and the manifold 9 are manufactured by a cutting process or the like.
Is fixed. Further, a plurality of conductive patterns 23 corresponding to the electrodes 15 are formed on the surface of the cover plate 5, and the driver chip 21 is connected and fixed to one end of the conductive patterns. Subsequently, as shown in FIG.
2, a plurality of small spherical solder bumps 31 are formed in the longitudinal direction (FIG. 2).
(In the direction perpendicular to the plane of the drawing) at predetermined intervals, and an adhesive 33 is provided on the cover plate 5 exposed between the conductive patterns 23.
Is applied. Thereafter, the base plate 3 is superimposed on the cover plate 5, the two are adhered to each other with an adhesive 33, and the surface or a part of the solder bump 31 is heated and melted by reflowing to form the electrode 15 and the conductive pattern 23.
Are electrically connected.

Through the above steps, the main body of the ink jet head 1 can be manufactured as shown in FIG. After that, the inkjet head 1 is completed by fixing the nozzle plate 7 and the manifold 9. Thus, the inkjet head 1 can be easily manufactured without using an expensive FPC. Further, since the driver chip 21 is provided on the cover plate 5, the driver chip 21 and the conductive pattern 2 are provided.
3, and the configuration is further simplified. Therefore, the manufacturing cost of the device can be favorably reduced.
Further, even if the driver chip 21 generates heat, the heat can be radiated through the cover plate 5, so that the temperature rise of the driver chip 21 can be prevented, and the reliability of the device can be improved.

Further, when connecting the electrode 15 and the conductive pattern 23, it is conceivable to provide solder on the entire surface of the conductive pattern 23. However, the ink jet head 1 uses small spherical solder bumps 31. Solder bump 31
Has a surface or a part made of a low-temperature melting material, which abuts the conductive pattern 23 and the electrode 15 in a point-like manner, and the fused portion establishes an electrical connection between the electrode 15 and the conductive pattern 23 while having a small area. It can be ensured reliably. The electrode 15 is arranged with a slight gap from the lower end of the side wall 17, and the solder bump 31 connects the electrode 15 and the conductive pattern 23 across the gap. Therefore, when the solder bumps 31 are melted, the solder bumps 31 are securely adhered to the electrodes 15 and the conductive patterns 23 by the surface tension, and the electrical connection between the two can be more reliably ensured. Further, the solder bumps 31 do not protrude from between them and adhere to extra places. Therefore, in the inkjet head 1, the reliability of the device can be further improved.

It should be noted that the present invention is not limited to the above-described embodiment at all, and can be implemented in various forms without departing from the gist of the present invention. For example, a silicon wafer or a resin substrate may be used as the cover plate 5 in addition to the ceramic substrate, and gold or the like may be used as the connection portion in addition to solder. In this case, the same effect as above can be obtained. However, when a silicon wafer is used, heat dissipation is improved, but the cost is slightly increased. Further, the driver chip 21 may be provided on the lower surface of the cover plate 5 (the surface opposite to the base plate 3) and connected to the conductive pattern 23 via a well-known through hole. In this case, although the configuration is slightly complicated and the manufacturing cost is increased, the size of the inkjet head 1 can be further reduced. Furthermore, in the ink jet head 1, although the entire base plate 3 is made of piezoelectric ceramics as the piezoelectric portion, only a part of the side wall 17 of the base plate 3 may be used as the piezoelectric portion. Alternatively, the conductive patterns 23 may be provided on both the upper and lower surfaces of the cover plate 5 and the base plates 3 may be fixed on both surfaces to form the nozzles 7a in two rows.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating a configuration of an inkjet head to which the present invention has been applied.

FIG. 2 is an explanatory view illustrating a method of manufacturing the ink jet head.

FIG. 3 is an exploded perspective view illustrating a configuration of a conventional inkjet head.

[Explanation of symbols]

1. Inkjet head 3. Base plate
5 ... Cover plate 7 ... Nozzle plate 7a ... Nozzle
11 ... groove 13 ... ink liquid chamber 15 ... electrode
17 ... side wall 21 ... driver chip 23 ... conductive pattern
31 ... Solder bump

Claims (4)

[Claims] 1. A base plate having a groove formed at least in part by a side wall that is a piezoelectric portion, a cover plate covering the groove to form an ink liquid chamber, and a piezoelectric plate provided on the side wall. An ink, comprising: an electrode; and a nozzle communicating with the ink liquid chamber, wherein a drive voltage is applied to the electrode to deform the side wall, thereby causing pressure oscillation in the ink liquid chamber to eject ink from the nozzle. An injection device, comprising: a conductive pattern formed on a surface of the cover plate facing the electrode; and a substantially small brazing filler metal, and electrically connects the electrode and the conductive pattern facing the electrode. An ink ejecting apparatus, comprising: a connecting portion; 2. The electrode according to claim 1, wherein the electrode and the conductive pattern are disposed with a gap therebetween, and the connecting portion connects the electrode and the conductive pattern across the gap. Ink ejection device. 3. The cover plate is formed to be longer than the base plate, and the conductive pattern is formed to extend to a portion of the cover plate that does not face the base plate, and does not face the base plate of the cover plate. 2. A driver chip for applying the driving voltage via the conductive pattern is provided at the portion.
Or the ink ejecting apparatus according to 2. 4. A base plate having a groove formed at least in part by a side wall that is a piezoelectric portion, a cover plate covering the groove to form an ink liquid chamber, and a piezoelectric plate provided on the side wall. An ink, comprising: an electrode; and a nozzle communicating with the ink liquid chamber, wherein a drive voltage is applied to the electrode to deform the side wall, thereby causing pressure oscillation in the ink liquid chamber to eject ink from the nozzle. A method of manufacturing an injection device, comprising forming a conductive pattern on a surface of the cover plate facing the electrode, disposing a substantially small-sized brazing material on the conductive pattern facing the electrode, A method of manufacturing the ink jet apparatus, wherein the base plate is superimposed on the cover plate, and the electrode and the conductive pattern are electrically connected by the brazing material. .