JPH10291323A - Manufacture of ink jet printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bond upper and lower substrates through a thin homogeneous adhesive layer of uniform thickness. SOLUTION: A thin film 16 is formed partially on one side of a lower substrate 2 and an upper substrate 3 is bonded onto the thin film 16 to form a gap matching the thickness of the thin film 16 between the upper and lower substrates 3, 2. After the gap is filled with a low viscosity adhesive 18 utilizing surface tension, the adhesive 18 is hardened to form a substrate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an on-demand type ink jet printer head using a piezoelectric member.

[0002]

2. Description of the Related Art Conventionally, a nozzle plate having an ink discharge port is fixed to the tip of an ink chamber which is connected to an ink supply section and acts as a number of pressure chambers arranged in parallel, and the ink pressure in the ink chamber is increased to increase the ink pressure. 2. Description of the Related Art There is an ink jet printer head which causes ink to fly from a discharge port.

As a method of increasing the ink pressure in the ink chamber, at least a part of the side walls arranged on both sides of the ink chamber is formed by a piezoelectric member, electrodes are provided on the side surfaces of the side walls, and a voltage is applied to the electrodes. The side wall is deformed by applying the voltage, and the direction of the side wall is changed according to the polarity of the applied voltage at this time, thereby expanding the volume of the ink chamber and sucking ink from the ink supply unit, or reducing the volume of the ink chamber. Japanese Patent Application Laid-Open No. 63-247051 discloses a method of discharging the internal ink from an ink discharge port.

[0004]

The side wall formed at least in part by a piezoelectric member is formed by forming a groove by machining a substrate in which a lower substrate and an upper substrate are bonded. In forming this substrate, it is required that the adhesive layer between the lower substrate and the upper substrate be uniform and thin. In the technique disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 63-247051, the manufacturing method is not mentioned. I haven't.
For this reason, a thin adhesive layer is formed by a method such as screen printing of an adhesive.However, there is a risk that air bubbles may be mixed in, and it is not possible to form a thin adhesive layer having a uniform and uniform thickness. Have difficulty.

An object of the present invention is to bond a lower substrate and an upper substrate with a thin adhesive layer having a uniform and uniform thickness.

[0006]

According to the first aspect of the present invention,
A plurality of grooves opened on one side and an end face of the substrate formed by a lower substrate and an upper substrate, at least one of which is made of a piezoelectric member, are partitioned by sidewalls and formed in parallel with each other, and the grooves are closed on one surface of the substrate. In an ink jet printer head in which a top plate is adhered and a nozzle plate for closing the groove is adhered to an end surface of the substrate, and the groove is used as an ink chamber, a thin film is formed on a part of one surface of the lower substrate. The upper substrate is joined to form a gap between the upper substrate and the lower substrate corresponding to the thickness of the thin film, and after filling the gap with a low-viscosity adhesive, the adhesive is cured. To form the substrate. Therefore, the thickness of the adhesive layer is defined by the thin film formed on one surface of the lower substrate, and the gap is filled with a low-viscosity adhesive using surface tension. A thin adhesive layer can be formed, and an adhesive layer with less air bubbles can be formed.

According to a second aspect of the present invention, a positive pressure or a negative pressure is applied to the adhesive so as to fill the gap formed between the upper substrate and the lower substrate. Therefore, it is possible to efficiently fill the adhesive with no air bubbles in the gap.

[0008]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. First, in FIG. 1, an ink jet printer head 1 is configured such that a head plate 6 is bonded or joined to a substrate 4 in which at least one of a lower substrate 2 and an upper substrate 3 each made of a piezoelectric member is laminated and integrated. The head body 6 has a thickness of 10 to 100
It is formed by bonding a nozzle plate 7 of about μm.

Thus, the substrate 4 of the head body 6 is
A pressure generating means 8 is provided. For example, the lower substrate 2 and the upper substrate 3 polarized in directions opposite to each other are
A plurality of grooves 9 which are formed by a piezoelectric member made of T, reach from the upper surface of the upper substrate 3 to the inside of the lower substrate 2 below, and open to the front side and are closed at the rear, are formed by being separated by side walls 10. I have. These grooves 9 are formed by grinding in parallel with a diamond wheel or the like of a dicing saw used for cutting an IC wafer or the like.
Drive unit. Electrodes 11 are formed on the inner surface of the groove 9 by electroless nickel plating. These electrodes 11 extend from the rear of the groove 9 to the upper surface of the upper substrate 3 and are formed by electroless nickel plating. At the same time, a wiring pattern 12 is formed. This wiring pattern 12
Is connected to an external circuit (not shown) for supplying a control signal for selectively applying a voltage to the electrode 11.

The size of the groove 9 formed in the substrate 4 is, for example, about 400 μm in depth, about 80 μm in width, and about 10 mm in length.

The top plate 5 has a groove-shaped ink supply port 13 communicating with the rear end of the groove 9 of the substrate 4, and is bonded with an adhesive to cover the upper surface of the groove 9. The nozzle plate 7 having the ink discharge ports 14 provided at the pitch of the grooves 9 is integrally adhered to the front surface of the head body 6 formed by fixing the top plate 5 with an adhesive.
As a result, the groove 9 is closed, and the inside thereof becomes the ink chamber 15.

The operation of the ink jet printer head 1 will be described. That is, ink is supplied into the ink chamber 15 from the ink supply port 13 connected to the ink supply unit by a supply unit such as a tube. And
When a voltage is applied to or cut off from the electrode 11 of the selected side wall 10, the side wall 10 made of a piezoelectric member formed in a state where the polarization directions are opposite to each other is curved by shear mode deformation, and the opposing side walls 10 gradually separate. Then, the ink in the ink chamber 15 is pressurized by suddenly returning to the initial position, and ink droplets are ejected from the ink ejection port 14. At this time,
In order to prevent crosstalk, even-numbered ink chambers 15
The voltage applied to the electrode 11 is selected so as to alternately pressurize the and the odd-numbered ink chambers 15, and the deformation of the side wall 10 is controlled. Thus, the deformation state of the side wall 10 depends on the ink chamber 1.
5 when the ink is sucked, the ink gradually deforms, and when the filled ink is pressurized, the ink rapidly deforms. In addition,
It is desirable that the cross-sectional shape of the ink discharge port 14 is tapered so that the diameter on the inner surface side is large and the diameter on the outer surface side is small.

As described above, the operation of sucking and discharging the ink is performed by the deformation of the side wall 10. These side walls 10 have an adhesive portion between the lower substrate 2 and the upper substrate 3 at an intermediate portion thereof. The thickness of the adhesive layer at this adhesive portion is uniform, and if there is no air bubble mixing or the like. This state is a necessary condition for ejecting ink droplets from all the ink ejection ports 14 in a stable state. The present embodiment can meet such a demand, and can bond the lower substrate 2 and the upper substrate 3 with a uniform thickness without air bubbles. is there.

First, in FIG. 2, a strip-shaped thin film 16 is formed on both left and right edges of the upper surface of the lower substrate 2. This thin film 16
Is a spacer and is formed by electroless nickel plating to a thickness of 2 to 3 μm. This thin film 16
May be formed by vapor deposition, sputtering, or the like, in addition to the method of electroless nickel plating. It is essential that the thin film 16 has a separation portion on the near side and on the back side. As shown in FIG. 2, the thin film 16 is formed in a band shape with the left and right side edges separated from each other. desirable.

Next, as shown in FIG. 3, the upper substrate 3 is joined by being brought into contact with the thin film 16, and a pressing jig 17 having a large thickness is placed on the upper substrate 3 and pressed at a constant pressure. . This pressurized state is used to prevent the lower substrate 2 and the upper substrate 3 from being displaced from each other and to stably form a gap corresponding to the thickness of the thin film 16 therebetween. It is. In this state, low viscosity (5
(0 cp or less). At this time, due to the surface tension of the adhesive 18, the adhesive 18 is drawn into the gap and is filled in the gap. Then, the adhesive 18 is cured while being pressed by the pressing jig 17.
Therefore, the adhesive 18 is drawn into the gap by the surface tension and hardened, so that no bubbles are mixed into the adhesive layer. In addition, the thickness of the adhesive layer also matches the thickness of the thin film 16, and the thickness is determined when the thin film 16 is formed, so that stable dimensional accuracy can be obtained.

The type of the adhesive 18 may be an organic adhesive or an inorganic adhesive as long as it can withstand the ink used. In the case of a thermosetting adhesive, the heating temperature for curing must be 200 ° C. or less, which does not affect the polarization of the piezoelectric member.

In the illustrated state, the size of the lower substrate 2 and the size of the upper substrate 3 are different, and the end faces of both are not aligned after bonding. In order to be able to bond the nozzle plate 7 as the substrate 4, the front surface to which the nozzle plate 7 is bonded must be flat. Therefore, machining is performed so that a flat front surface is formed after bonding. Further, it is also possible to perform bonding after aligning the end surfaces of the lower substrate 2 and the upper substrate 3, and in this case, an auxiliary tool for supplying the adhesive 18 to the gap between them is used.

Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those described in the above embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, a closing jig 19 that covers one of the gaps is provided in a state where the lower substrate 2, the upper substrate 3, and the pressing jig 17 are stacked, and a flow path formed in the closing jig 19 is provided. The adhesive 18 pressurized by a pressure applying means (not shown) is supplied from 20 to the opening on one side of the gap.

Accordingly, as described above, not only the surface tension of the adhesive 18 but also a predetermined pressure acts simultaneously, so that the adhesive 18 flows into the gap smoothly, and the time is short. Performs the filling operation.

Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, similar to the second embodiment, a closing jig 19 that covers one of the gaps is provided in a state where the lower substrate 2, the upper substrate 3, and the pressing jig 17 are stacked. Further, a bank member 21 whose upper edge is higher than the upper substrate 3 is provided at the other end of the lower substrate 2. Then, the adhesive 18 is stored in the storage portion 22 formed by the bank member 21 and then the adhesive 18 is drawn into the gap by applying a negative pressure from the flow path 20 of the closing jig 19. . Also in this case, the bonding can be performed efficiently as in the second embodiment.

[0021]

According to the first aspect of the present invention, a plurality of grooves, which are formed by a lower substrate and an upper substrate, at least one of which is formed by a piezoelectric member, are formed on one surface and an end surface of the substrate by a side wall and are parallel to each other. An ink jet printer head, wherein a top plate closing the groove is bonded to one surface of the substrate and a nozzle plate closing the groove is bonded to an end surface of the substrate, and the groove is used as an ink chamber; A thin film is formed on a part of one surface of the substrate, and the upper substrate is joined to the thin film to form a gap between the upper substrate and the lower substrate corresponding to the thickness of the thin film. After the adhesive is filled, the adhesive is cured to form the substrate, so that the thickness of the adhesive layer is defined by a thin film formed on one surface of the lower substrate, and the surface tension is utilized. Filling the gap with a low-viscosity adhesive makes it possible to form a thin and uniform adhesive layer with a uniform thickness, and to form an adhesive layer with less air bubbles. Having.

According to the second aspect of the present invention, a positive pressure or a negative pressure is applied to the adhesive so that the adhesive fills a gap formed between the upper substrate and the lower substrate.
This has the effect that the adhesive can be efficiently filled with no air bubbles in the gap.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an example of an inkjet printer head according to the present invention.

FIG. 2 shows the first embodiment of the present invention, and is a perspective view of a state where a thin film is formed on one surface of a lower substrate.

FIG. 3 is a perspective view of a state where a lower substrate and an upper substrate are bonded to each other.

FIG. 4 is a vertical sectional side view showing a second embodiment of the present invention.

FIG. 5 is a vertical sectional side view showing a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet printer head 2 Lower substrate 3 Upper substrate 4 Substrate 5 Top plate 7 Nozzle plate 9 Groove 10 Side wall 15 Ink chamber 16 Thin film 18 Adhesive

Claims (2)

[Claims] 1. A plurality of grooves, which are formed on a surface and an end surface of a substrate formed by a lower substrate and an upper substrate, at least one of which is formed of a piezoelectric member, are formed by a side wall and formed in parallel with each other. In an ink jet printer head in which a top plate for closing the groove is bonded and a nozzle plate for closing the groove is bonded to an end surface of the substrate and the groove is used as an ink chamber, a thin film is formed on a part of one surface of the lower substrate. And bonding the upper substrate to the thin film to form a gap between the upper substrate and the lower substrate corresponding to the thickness of the thin film. A method of manufacturing an ink jet printer head, characterized in that the substrate is formed by curing the adhesive after filling the agent. 2. The method according to claim 1, wherein a positive pressure or a negative pressure is applied to the adhesive so that the adhesive fills a gap formed between the upper substrate and the lower substrate. A method for manufacturing an ink jet printer head.