JP2000229414A - Manufacture of ink jet printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To plate the inside of a plurality of juxtaposed grooves uniformly with strong adhesion. SOLUTION: Piezoelectric members 17, 18 polarized in the plate thickness direction or a substrate 19 integrating the piezoelectric members 17, 18 with a base member 16 is provided and a plurality of grooves 20 of specified depth and width opening above the surface side of the substrate 19 and closed at the opposite ends in the longitudinal direction are made in parallel in the widthwise direction. Recesses 23 communicating with the grooves 20 in the orthogonal direction are made in the center of these grooves 20, an electrode 24 is formed by electroless plating at least at a part of a post 22 separating the adjacent grooves 20 and then the substrate 19 is cut in the direction orthogonal to the grooves 20 tus forming a head substrate. Subsequently, it is fixed with a top plate covering the upper part of a channel defined by the groove 20 and a nozzle plate covering the front part of the groove 20 to form a plurality of ink chambers surrounded by the grooves 17, 18, the top plate and the nozzle plate thus forming a plurality ink jet printer head from the substrate 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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, there are various types of on-demand type ink jet printer heads, for example, as disclosed in Japanese Patent Application Laid-Open No. 8-281957.
There is known an apparatus that discharges ink droplets by using shear mode deformation of a piezoelectric member caused by application of electric power. When a large number of printer heads shown here are produced by mass production or the like, generally, as shown in FIG. 7 (c), for the purpose of cost reduction and the purpose of forming the flow path by mechanical processing, A substrate 4 is formed by laminating and integrating two piezoelectric members 1 and 2 having different polarization directions and a base member 3, and a flow path formed by a large number of grooves 5 formed parallel to one surface of the substrate 4. 6 are provided in two rows (four heads in the figure). A method and structure for manufacturing an ink jet printer head using the substrate 4 will be described with reference to FIGS. 4 and 7 to 9. Fig. 7
As shown in (a), a two-layer piezoelectric member 2 or 3 is adhered on a base member 1 so that the polarization direction is opposite to the thickness direction to form a substrate 4 having a three-layer structure. Next, FIG.
As shown in (b) and (c), U-shaped flow paths 6 and struts 7 are formed at equal intervals from the surface of the piezoelectric member 3 to the inside of the piezoelectric member 2 at equal intervals on the substrate 4 by grinding. I do. Then, a dry film 8 is adhered to the surface of the substrate 4 as shown in FIG. 7 (d) to form a predetermined pattern by a photo process. Then, an electrode 9 and a wiring pattern 10 are formed on the plane portion. As shown in FIG. 9, the ink supply path 1 is formed on the substrate 4 on which the electrode pattern is formed.
1 is bonded to the top plate 12 in which
The nozzle plate 14 having the ink discharge port 13 formed thereon is adhered to the four parts by cutting at a groove AA ′ at the center of the substrate 4 and the center of the substrate 4. Are connected to form an ink jet printer head as shown in FIG.

[0003]

However, in the above-mentioned step of forming the electrodes 9 on the substrate 4 by electroless plating, it is necessary to form irregularities on the surface of the substrate 4 to be plated to increase the adhesion of the plating layer. Have been done. However, since the pretreatment solution and the plating solution for attaching the etching and the catalyst nucleus stay at the bottom of the flow channel 6 and the replacement is not sufficiently performed, the plating on the bottom portion is smaller than the plating film on the upper portion of the flow channel 6. The film has a weak adhesion and is thin. When the substrate 4 is divided at the center of the flow path 6 composed of the groove 5 whose both ends are closed in the length direction, the plating film floats or peels off at the bottom of the flow path 6 having a weak adhesion, and the ink is removed. There is a problem that the ejection characteristics are greatly affected.

An object of the present invention is to solve the problems described above and to provide a method of manufacturing an ink jet printer head which enables formation of a strong plating layer with uniform adhesion inside the groove 5. I do.

[0005]

According to the first aspect of the present invention,
A piezoelectric member polarized in the plate thickness direction or a substrate formed by integrating the piezoelectric member and the base member is provided, and a predetermined depth is formed on the front surface side of the substrate, which is opened upward and both ends in the length direction are closed. And a plurality of grooves having a width are formed in parallel with the width direction, a concave portion communicating with the direction perpendicular to these grooves is formed at a central portion of these grooves, and an electroless is formed on a side wall of a column separating the adjacent grooves. Form electrodes by plating method,
The substrate is cut in a direction perpendicular to the groove to form a head substrate, and a top plate covering an upper portion of a flow path formed by the groove and a nozzle plate covering a front portion of the groove are attached to the head substrate. A plurality of ink chambers surrounded by the groove, the top plate, and the nozzle plate to form a plurality of ink jet printer heads from the substrate.

According to a second aspect of the present invention, in the first aspect, the groove width of the concave portion is set to 0.4 mm or more.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. The process of manufacturing an inkjet printer head is basically the same as the conventional one,
Next, details will be described in order. First, as shown in FIG. 1 (a), two layers of piezoelectric members 17 and 18 are adhered on a base member 16 made of ceramics so that their polarization directions are opposite to each other as shown by an arrow, thereby forming a three-layer structure. Is formed. Next, by grinding the substrate 19, a plurality of grooves 20 extending from the surface of the piezoelectric member 18 to the inside of the piezoelectric member 17 and being parallel to each other as shown in FIGS. A plurality of rows (two rows in the drawing) of the flow path 21 and the support columns 22 are formed, and a groove-shaped recess 23 deeper than the flow path 21 is formed in the center of the groove 20 in a direction perpendicular to the flow path 21. Here, the thickness of the substrate 19 is 1.5 mm,
The width of 0 is 70 μm, the depth is 300 μm, the depth of the recess 23 is 0.5 mm, and the width is 0.2 m from 0 (conventional) to 1 mm.
Six types of substrates 19 were prepared by changing m. Next, electrodes 24 are formed on these substrates 19 by electroless plating. First, a dry film 25 is attached to the surface of the piezoelectric member 18 using a laminator on the cleaned substrate 19 as shown in FIGS. 2A and 2B, and is exposed and developed using a photomask 26. A resist pattern 27 as shown in FIG. 2C is formed. The dry film 25, which is a resist, cures when exposed to light.
If the photomask 26 is such that the portion 3 is shielded from light, it is removed during development. Next, as a pretreatment of the electroless plating method, the resist patterns 27 on the piezoelectric members 17 and 18 are formed.
A sensitizing treatment in which Sn adsorption and etching are immersed in a SnF ₂ + HF solution for a predetermined time while being stirred for a portion not covered with Sn, and a Sn is immersed in an AgNO ₃ solution while being stirred for a predetermined time to form Sn and Sn. The first-stage activation treatment in which Ag is adsorbed by the substitution reaction of Ag, and the Pd by the substitution reaction of Ag and Pd by being immersed in a solution of PdCl ₂ + HCl with stirring for a predetermined time.
And a second-stage activation treatment for adsorbing the. Then, Pd which is a catalyst core of electroless nickel plating
Is removed with a NaOH solution. Next, a Ni-B plating solution having good conductivity,
The electrode 24 is continuously immersed in a Ni-P plating solution having good corrosion resistance to form a two-layer electrode 24 having a plane portion with a thickness of 2 μm. Here, when the substrate 19 is immersed in each plating tank, vibration is applied to the substrate 19 and plating is performed from the vertical direction so that the generated hydrogen gas is removed and the plating solution is replaced in the flow path 21. Injecting liquid. The top plate 29 on which the ink supply passage 28 is formed in advance as shown in FIG. 3 is bonded to the substrate 19 on which the electrodes 24 are formed as shown in FIG. 4A is cut by the portion at −A ′, the nozzle plate 31 in which the ink discharge port 30 is formed in advance is bonded to this, and an ink supply pipe (not shown) is connected. Is completed as shown in FIG. When the substrate 19 having the wide recess 23 was divided, the substrate 19 was cut using a wide blade. Here, the film thickness distribution of the electrode 24 formed in the groove 20 is caused by the substitution of the pretreatment liquid and the plating liquid. It is related to the lifting and peeling of the film, and has a great influence on the ink ejection characteristics. Therefore,
When the thickness of the nickel plating film and the floating / peeling of the nickel plating film on the inner surface of the groove 20 as viewed from the cut surface when the substrate 19 was divided for each groove width were examined, the results shown in FIG. 5 were obtained. The ratio of the vertical axis in the drawing represents the film thickness at the bottom of the groove 20 when the film thickness at the top of the groove 20 is 1, and the substrate of the conventional structure in which the groove width at the back is 0. Is 0.4 or less, which is less than half, whereas 0.72 at 0.2 mm, 94 at 0.4 mm,
The film thickness distribution is improved as the groove width of the concave portion 23 is increased to 0.96 at 0.8 mm and 1 at 0.8 mm, and to 0.4 mm.
Thus, it can be considered that a substantially uniform plating film is formed in the flow channel 21. In addition, the groove width of the concave portion 23 is set to 0.
When the thickness is 2 mm or less, floating or peeling of the plating film is observed, whereas when the thickness is 0.4 mm or more, there is no such thing and it can be determined that the adhesion is good. In this embodiment, the dry film 2 is formed after the grooves 20 and the concave portions 23 are formed.
5, the resist pattern 27 is formed. However, after the pattern is formed on the planar substrate 19 with a liquid resist, the groove 20 and the concave portion 23 may be formed in accordance with the pattern. In the present embodiment, the two-layer piezoelectric member 1
Although the inkjet printer head 33 uses the substrate 19 having the substrates 7 and 18, the substrate 19 to which the present invention can be applied is used.
As long as at least one piece of the piezoelectric member 17 or 18 is used, the piezoelectric member 17 or 18 may be laminated on a lower layer portion formed of a resin, or, on the contrary, the piezoelectric member 17 or 18 may be used. A substrate 19 in which an upper layer made of a resin is laminated on the substrate 18 may be used.

The substrate 19 used in the ink jet printer head 33 in the above-described embodiment will be described.
Similar trial production was performed for the formation of a plating film in the range of groove width 50 to 120 and depth 250 to 500 μm, and confirmation was performed. The same result as the substrate 19 in the dimensions described above was obtained. The depth of the recess 23 was set at 0.5 mm as described above, but at least
If the depth is equal to or greater than, similar results were obtained.

Next, another embodiment of the present invention will be described with reference to FIG. In the present embodiment, the base substrate 3 is formed by laminating two base plates 34 and 35 made of an alumina substrate or the like.
6 are formed, and two grooves 37 are formed on one surface of the base substrate 36.
To form The two piezoelectric members 3 are inserted into the groove 37.
The substrate 40 is formed by embedding a laminate of the substrates 8 and 39 and bonding them with an adhesive. The substrate 40 thus formed
A large number of grooves 41 similar to the grooves 20 described above are formed in the portions of the piezoelectric members 38 and 39, and
A recess 42 is formed at the center of 9 in a direction perpendicular to the groove 41.

The state thus formed has the same shape as that of FIG. 1C in the above-described embodiment, and the subsequent steps of forming the electrode 24 and other steps are performed in the same manner. Therefore, the piezoelectric members 38 and 39 can be formed by embedding as well as a type in which flat members are stacked. Therefore, the amount of the expensive piezoelectric members 38 and 39 used can be reduced, and the cost can be reduced.

In each of the above-described embodiments, an example of the ink jet print head 33 has been described. However, similarly, when plating is performed on a member having a fine groove portion and particularly having a depth greater than the groove width direction. Can be implemented in a similar manner.

[0012]

According to the first aspect of the present invention, a piezoelectric member polarized in a plate thickness direction or a substrate formed by integrating the piezoelectric member and a base member is provided, and an upper opening is formed on the front side of the substrate. A plurality of grooves having a predetermined depth and width whose both ends in the length direction are closed are formed parallel to the width direction,
A concave portion communicating with the groove in a direction perpendicular to the groove is formed at a central portion of the groove, an electrode is formed on a side wall of a column separating the adjacent groove by an electroless plating method, and the substrate is orthogonal to the groove. Cut in the direction to form a head substrate, a top plate that covers the upper part of the flow path formed by the groove and a nozzle plate that covers the front part of the groove are attached to the head substrate, and the groove and the top plate are attached. Since a plurality of ink chambers surrounded by the nozzle plate are formed to form a plurality of ink jet printer heads from the substrate, the same operation as when the grooves are released, that is, the etching liquid And the pretreatment liquid and the plating liquid are sufficiently replaced at the bottom of the flow path, and an electrode having a uniform adhesion and a uniform film thickness can be formed.
Since it is possible to provide an ink jet printer head with stable ink ejection characteristics, and because it is possible to advance the process in units of multi-cavity substrates before dividing into heads such as electrode formation and top plate bonding, This has the effect of contributing to a reduction in man-hours.

According to a second aspect of the present invention, in the first aspect of the present invention, the groove width of the concave portion is set to 0.4 mm or more.
The same effect as the opening of the groove, that is, the etching solution, the pretreatment solution, and the plating solution are sufficiently replaced even at the bottom of the flow path, and an electrode having a uniform adhesion force and a uniform film thickness can be formed. Has an effect.

[Brief description of the drawings]

FIGS. 1A and 1B show an embodiment of the present invention, in which FIG. 1A is a side view in which a base member and a piezoelectric member are stacked, FIG. 1B is a side view in a state in which a groove is formed, and FIG. (D) is a perspective view seen from the upper surface side.

2 (a) is a side view showing a state in which a dry film is attached to a substrate, FIG. 2 (b) is a perspective view showing a state where exposure is performed using a photomask, and FIG. () Is a perspective view in a state where a resist pattern is formed, and (d) is a perspective view in a state where electrodes are formed.

FIG. 3 is a side view in a state where a top plate is adhered and a part of a cut position is cut away.

FIG. 4 is a perspective view of the inkjet printer head with a part cut away.

FIG. 5 is a graph showing a ratio of occurrence of floating or peeling of a plating layer with respect to a width of a groove.

FIG. 6 is a side view showing another embodiment of the present invention.

7A and 7B show an example of a manufacturing process of a conventional inkjet printer head, wherein FIG. 7A is a side view in which a base member and a piezoelectric member are stacked, FIG.
(c) is a perspective view of a state where a dry film is attached, and (d) is a side view thereof.

FIG. 8 is a perspective view showing a state where electrodes are formed.

FIG. 9 is a side view in a state in which a top plate is adhered and a part of a cutting position is cut away.

[Explanation of symbols]

 16 Base member 17 Piezoelectric member 18 Piezoelectric member 19 Substrate 20 Groove 21 Flow path 22 Prop 23 Depression 29 Top plate 31 Nozzle plate 33 Inkjet printer head

Claims (2)

[Claims] 1. A piezoelectric member polarized in a plate thickness direction or a substrate formed by integrating the piezoelectric member and a base member is provided. The substrate is opened on the front side of the substrate and both ends in the length direction are closed. A plurality of grooves having a predetermined depth and width are formed in parallel in the width direction, a concave portion communicating with a direction orthogonal to these grooves is formed at the center of these grooves, and a column separating the adjacent grooves is formed. An electrode is formed on the side wall of the substrate by an electroless plating method, the substrate is cut in a direction perpendicular to the groove to form a head substrate, and a top plate and an upper surface of the groove that cover the upper part of the flow path formed by the groove are formed. A nozzle plate covering a front portion is attached to the head substrate to form a plurality of ink chambers surrounded by the groove, the top plate, and the nozzle plate, thereby forming a plurality of ink jet printer heads from the substrate. What I did A method for manufacturing an ink jet printer head, comprising: 2. The method according to claim 1, wherein the groove width of the concave portion is 0.4 mm or more.