JP2002103629A - Method for manufacturing shear mode head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a shear mode head having good bubble breaking properties, low heat generation and ejecting both aqueous ink and solvent ink at low cost by a simple wet technology. SOLUTION: Two polarized piezoelectric plates 1a and 1b are bonded while directing the direction of polarization oppositely to form a head and after the upper surface thereof is coated with a plating resist layer 2, ink grooves 3 and air grooves 4a and 4b extending back and forth are made alternately. After a plating catalyst is adsorbed by etching, an electrode is formed by electroless plating and an organic insulation film is formed thereon by electrodeposition. Subsequently, a part of the plating film is removed by means of laser to form head wiring. Finally, a top plate, a nozzle plate and a manifold are bonded and connected with a flexible print cable through an anisotropic conductive film.

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 a shear mode head, and more particularly, to a very simple method mainly based on a wet method and a low cost method, which has good bubble removal properties and a driving frequency. The present invention relates to a method for manufacturing a high-performance shear mode head which is high in heat generation, generates little heat, and can be ejected with either a water-based ink or a solvent-based ink.

[0002]

2. Description of the Related Art The principle of a shear mode head is that a plurality of parallel grooves are ground on a polarized piezoelectric element plate to form ink grooves, electrodes are provided on the side walls of the ink grooves, and both sides of the side wall are sandwiched therebetween. When an electric field is applied between the electrodes existing in the above, the side wall is sheared and deformed, and pressure is applied to the ink to discharge the ink. However, since the ink is ejected by deforming the side wall of the ink groove, the influence of the ejection is transmitted to the adjacent groove, and not only the ink meniscus of the ejected ink groove but also the ink meniscus of the adjacent ink grooves vibrate. Until the vibration of the ink meniscus is stopped, not only the ejected ink grooves but also the ink grooves adjacent to the ink meniscus cannot be ejected, so that there is a problem that the printing speed is reduced.

For this reason, a technique for increasing the printing speed by alternately providing ink grooves and air grooves has been proposed.

For example, Japanese Patent Application Laid-Open No. 63-247051 discloses a method of driving a head having an ink groove and an air groove, applying a voltage to an electrode on the ink groove side, grounding the electrode on the air groove side, and driving the head. A yam mode head is disclosed. However, this technique has a disadvantage that only solvent ink can be ejected. That is, since the electrode of the ink chamber is in contact with the ink,
When a water-based ink is used, water is electrolyzed on the electrode surface, and oxygen is generated. Since the theoretical decomposition voltage of water is 1.23V, even at a voltage of 1-2 volts, water is electrolyzed,
Countless fine bubbles are generated from the electrode surface, and at the same time, the electrode is anodized and dissolved. When bubbles enter the ink, the pressure applied to the ink for ejection is absorbed by the bubbles, and ejection becomes impossible.

Japanese Patent Application Laid-Open No. 7-132589 discloses that
There is disclosed a shear mode head in which the electrodes of the ink chamber are grounded and the electrodes of the air chamber are driven by applying a voltage.

In this driving method, no voltage is applied to the ink chamber, so that there is no problem of bubble generation as in the technique described in JP-A-63-247051, and there is an advantage that water-based ink can be discharged. There is a disadvantage that electrode formation is extremely difficult.

[0007] Japanese Patent Application Laid-Open No. 8-174822 and
Each publication of 309977 discloses a method of manufacturing a shear mode head by electroless plating and grinding.

According to Japanese Patent Application Laid-Open No. 8-174822, a shallow groove which extends in the front-rear direction and which becomes an ink groove and a deep groove which becomes an air groove which extends in the front-rear direction are formed on two polarized PZT plates. The two PZT plates are bonded so that the grooves face each other. On the ceiling of the head, a groove extending perpendicularly to the groove and reaching the air groove, but not reaching the ink groove, is ground. Further, a vertical groove extending in the up-down direction and leading to the ink chamber is formed in the front wall. The entire surface is subjected to electroless plating, the front end is cut, and further, a shallow groove extending left and right is formed on the ceiling to separate the ground and the signal. Further, a shallow groove extending back and forth is formed in the ceiling above the air chamber to form individual wirings leading to the ink chamber.

In this method, it is necessary to cover the groove, form an ink chamber and an air chamber, and then perform electroless plating on the inner surfaces thereof. During electroless plating, a large amount of hydrogen is generated from the plating location, so if you cover the groove and form the ink chamber and air chamber before plating, the generated bubbles are difficult to escape, the bubbles are stored, and the stored bubbles However, there is a disadvantage that the deposition of the plating is hindered.

Further, in these methods, a vertical groove is ground on the entrance side of the ink chamber in order to connect to an electrode formed in a straight ink flow path, and a wiring is formed in this groove. Since this groove is also used as an ink inlet groove, there is a disadvantage that the ink flow path bends in a crank shape at this portion, and that air bubbles, dust and the like accumulate at this portion, and ink leaks from the vertical groove.

It is conceivable to completely seal the flutes in order to prevent dust and bubbles from accumulating in the flutes, and to prevent ink leakage. Since there are several hundreds, several tens to several hundreds of tens of μ
It is difficult to completely seal the order area without affecting the ink flow path.

Further, in these methods, a groove 2 is formed.
If the grooves of the PZT plates are not adhered with the grooves aligned exactly, the adhesive applied to the bonding portion may overflow into the ink chamber and block the ink chamber.

Further, since these heads use a drive system in which a voltage is applied to the electrodes of the ink chamber, there is a disadvantage that the water-based ink cannot be ejected as described above.

Further, the electrodes of the conventional shear mode head are formed by depositing the electrodes on the side walls of the ink chamber. When a groove is formed with one sheet of PZT, it is necessary to provide an electrode in the upper half of the side wall, so that oblique deposition is performed. When the head is tilted and vapor deposition is performed from an oblique direction, the evaporated material is blocked by the side wall, and the vapor does not reach the lower half of the side wall.
However, if two PZTs are bonded with their polarization directions opposite to each other and then a groove is formed, the side walls are formed by two piezoelectric elements with opposite polarization directions, so that the two piezoelectric elements are driven. Therefore, it is necessary to form an electrode on the entire side wall, but it is extremely difficult to form an electrode on the lower half of the side wall by the conventional oblique deposition method.

[0015]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an extremely simple wet-type technique and a low-cost method as compared with these conventional dry-type techniques, and to provide good bubble removal properties.
It is an object of the present invention to provide a method of manufacturing a high-performance shear mode head that generates less heat and can be ejected with both a water-based ink and a solvent-based ink.

[0016]

The above object is achieved by the following invention. Conventionally, electrode formation has been performed by a vapor deposition method, and an insulating film has been performed by a CVD method (both are dry).
The electrode is formed by plating, and the insulating film is formed by electrodeposition.
The employment of the wet technology has a significant feature different from the conventional technology.

1. A method for manufacturing a shear mode head, comprising the following steps (1) to (11) in order.

(1) Step of joining two polarized piezoelectric element plates with their polarization directions opposite to each other to form a rectangular or cubic head (2) Coating a plating resist layer on the upper surface of the head (3) Forming ink grooves and air grooves extending in the front-rear direction on the upper surface side of the head, and alternately arranging the ink grooves and air grooves. (4) Etching the entire surface of the head for electroless (5) Electroless plating step of electroless plating on the catalyst adsorbing surface (6) Step of removing plating resist layer with alkali (7) Polishing the front wall of the head Step of removing the plating film (8) Electrodeposition step of electrodepositing an organic insulating film on the plating film formed in the electroless plating step (9) Part of the plating film on the rear wall and the bottom surface of the head is removed by laser. (10) bonding a top plate to the top surface of the head, a nozzle plate to the front wall of the head, and a manifold to the rear wall of the head. 11) A step of connecting the head wiring continuous from the rear wall to the bottom surface with a flexible printed cable (FPC) via an anisotropic conductive film (ACF).

2. A method for manufacturing a shear mode head, comprising the following steps (1) to (10) in order.

(1) A step of forming a rectangular or cubic head by bonding two polarized piezoelectric element plates with their polarization directions opposite to each other. (2) Coating a plating resist layer on the upper surface of the head. (3) Forming ink grooves and air grooves extending in the front-rear direction on the upper surface side of the head, and arranging the ink grooves and air grooves alternately. (4) Applying an electroless plating catalyst to the entire surface of the head. (5) A step of irradiating a laser to the catalyst other than the head wiring portion on the rear wall and bottom surface of the head to deactivate the catalyst (6) Electroless plating of the catalyst adsorption surface remaining on the head by electroless plating Plating step (7) Step of removing the plating resist layer with alkali (8) Electrodeposition step of electrodepositing an organic insulating film on the plating film formed in the electroless plating step (9) Polishing the front wall of the head Then plating skin (10) bonding a top plate to the top surface of the head, a nozzle plate to the front wall of the head, and a manifold to the rear wall of the head (11) head wiring continuous from the rear wall to the bottom surface Of connecting to a flexible printed cable (FPC) via an anisotropic conductive film (ACF)

In a preferred aspect of the present invention, in the step (3), both side walls of the ink groove are ground in a direction perpendicular to an upper surface of the head and are ground in parallel with each other.
The flexible printed cable (FPC) is a driving IC
It is connected to.

[0022]

Embodiments of the present invention will be described below.

First, the first invention will be described.

FIGS. 1 to 6 show (1) to (1) of the first invention.
It is a figure explaining each process of 1).

The step (1) is a step of fixing two polarized piezoelectric element plates 1a and 1b with their polarization directions opposite to each other to form a rectangular parallelepiped or cubic head (see FIG. 1). .

The method of shearing the polarized piezoelectric element plate wall is as follows. When a grooved wall is formed by one polarized piezoelectric element plate, an electrode is formed on the upper half of the wall and the upper half of the wall is sheared. There is a method of deforming, and when two polarized piezoelectric element plates are bonded with the polarization direction opposite to form a groove wall, an electrode is provided on the entire surface of the wall, and the entire wall is subjected to shear deformation. is there. The former only deforms the upper half of the wall, while the latter simultaneously deforms the upper and lower halves of the wall,
Since the deformation is performed in the opposite direction, the deformation amount is large and the deformation efficiency is good. Even when the same voltage is applied, the latter has a larger amount of wall deformation, so that the generated pressure is higher, the speed of the ejected ink droplets is faster, ink landing displacement is less, and the image quality is greatly improved. In addition, when the same displacement is applied, the latter requires only about half the voltage, so that heat generation of the head can be suppressed. For this reason, the present invention employs a method in which the latter two piezoelectric element plates are bonded with their polarization directions opposite to each other to form a wall, and electrodes are formed on the entire surface of the wall.

As the piezoelectric element plates 1a and 1b, a substrate formed of a piezoelectric material which is deformed by applying a voltage can be used. As the piezoelectric material, known materials can be used, and examples thereof include a piezoelectric substrate made of an organic material and a nonmetallic piezoelectric substrate. In particular, a non-metallic piezoelectric substrate is preferable.
A piezoelectric ceramic substrate formed through a process such as firing,
Alternatively, there is a substrate formed without the need for molding and firing.

Examples of the organic material for the substrate include an organic polymer such as polyvinylidene fluoride, a hybrid material of an organic polymer and an inorganic substance, and the like.

As the piezoelectric ceramic substrate formed through steps such as molding and firing, lead zirconate titanate (trade name "PZT") is preferable.

As PZT, PZT (PbZrO _3-
PbTiO ₃ ) and PZT with a third component added. Pb (Mg _1/2 Nb _2/3 ) O ₃ , P
b (Mn _1/3 Sb _2/3 ) O ₃ , Pb (Co _1/3 Nb _2/3 ) O ₃
And BaTiO ₃ , ZnO, LiNbO ₃ ,
LiTaO ₃ or the like may be used.

The substrate formed without the need for molding and firing can be formed by, for example, a sol-gel method, a laminated substrate coating, or the like. According to the sol-gel method, a sol is formed into a homogeneous solution having a predetermined chemical composition by adding water,
It is adjusted by adding an acid or an alkali to cause a chemical change such as hydrolysis. Further, by performing a treatment such as evaporation or cooling of the solvent, a sol in which fine particles of a target composition or a precursor of non-metallic or inorganic fine particles are dispersed can be prepared and used as a substrate. A compound having a uniform chemical composition can be obtained, including the addition of a small amount of a different element. As a starting material, generally a water-soluble metal salt or metal alkoxide such as sodium silicate is used,
A metal alkoxide is a compound represented by the general formula M (OR) n, which is easily hydrolyzed because the OR group has strong basicity, and undergoes a condensation process like an organic polymer to form a metal oxide or its water. Change to Japanese.

As a method of coating a laminated substrate, there is a vapor deposition method of depositing from a gas phase, and a method of forming a ceramic substrate from a gas phase includes a vapor deposition method by physical means and a chemical reaction from the gas phase to a substrate surface. Are classified into two types of chemical deposition methods. Furthermore, physical vapor deposition (PV
D) is subdivided into a vacuum deposition method, a sputtering method, an ion plating method and the like, and a chemical method includes a gas phase chemical reaction method (CVD), a plasma CVD method and the like. Vacuum evaporation as physical vapor deposition (PVD) is a method in which a target substance is heated and evaporated in a vacuum, and the vapor is deposited on a substrate. Sputtering is a method in which high-energy particles are applied to a target substance (target). To collide with atoms and atoms on the target surface.
This is a method in which molecules exchange momentum with colliding particles and utilize a sputtering phenomenon that is repelled from the surface. Further, an ion plating method is a method in which vapor deposition is performed in an ionized gas atmosphere. In the CVD method, a compound containing atoms, molecules or ions constituting a film is formed into a gaseous phase, and then guided to a reaction section with an appropriate carrier gas, and then reacted or deposited on a heated substrate. In the plasma CVD method, a gas phase state is generated by plasma energy, and a film is deposited by a gas phase chemical reaction in a relatively low temperature range from 400 ° C. to 500 ° C.

As means for joining the piezoelectric element plates 1a and 1b, joining using an adhesive can be adopted, but is not particularly limited as long as joining is possible. When the adhesive layer is formed using an adhesive, the thickness of the adhesive layer after curing is 5
A range of from 10 to 10 μm is preferred.

In this specification, since the direction of the head is important in describing the manufacturing process, the top and bottom surfaces, and the front and rear sides are clarified in FIG. In FIG. 1, the far side in the drawing is referred to as “front”, the near side is referred to as “rear”, the front surface is referred to as “front wall”, and the near wall is referred to as “rear wall”. Further, the upper side in the drawing is referred to as an “upper surface”, and the lower side is referred to as a “bottom surface”.

In the present invention, by the above-described joining,
A rectangular or cubic head 1 is formed.

Next, the step (2) is a step of applying a plating resist layer on the upper surface of the head. In FIG. 2, reference numeral 2 denotes a plating resist layer formed on the upper surface of the head 1. Means for forming the plating resist layer 2 includes:
Preferably, a coating solution of a plating resist is applied to a predetermined thickness by spin coating. Spin coating is preferable because it can be applied to a constant thickness with high accuracy.

As a coating agent for the plating resist, for example, an alkali-soluble novolak resin or the like can be used.

The dry film thickness of the plating resist layer is 5 to 1
A range of 0μ is preferred.

Next, in the step (3), as shown in FIG.
An ink groove 3 and air grooves 4a, 4b extending in the front-rear direction (a direction from the front wall 5 to the rear wall 6) are formed on the upper surface side of the head 1, and the ink grooves 3 and the air grooves 4a, 4b are alternately arranged. It is a process.

In this step, the ink grooves and the air grooves are alternately arranged, and if the air grooves are arranged between the ink grooves, the high-speed ejection can be achieved as pointed out in the prior art.

The groove is preferably formed by a known grinding machine.

In the present invention, the grooves are ground after the two PZT plates are bonded, so that the adhesive overflows into the ink grooves as compared with the method of bonding the two PZT plates whose grooves are ground. There is no fear.

The ink groove and the air groove are ground in the vertical direction as shown in the figure, and both side walls are formed parallel to each other. The depth penetrates through the resist layer 2 and the piezoelectric element plate 1a,
It is preferable to grind to reach the upper part of the piezoelectric element plate 1b.

The shape of the ink groove is a straight type in which the size and shape do not change at the entrance and the exit of the groove since the side walls of the groove are oriented vertically and are parallel to each other as described above. This is because bubbles are better removed, power efficiency is higher, heat generation is lower, and high-speed response is better than the conventional entrance shallow groove type.

To further mention this point, when ink is ejected from the head, first, the left and right walls of the ink groove are deformed outward, the ink groove is expanded, a negative pressure is generated in the groove, and the manifold is moved from the manifold to the groove. Suction ink. At this time, the generated negative pressure wave departs from the nozzle, moves in the groove, and is reflected at the entrance of the groove at the portion where the groove cross-sectional area changes suddenly, with its phase inverted. At this timing, if the deformation of the wall is restored and the ink is compressed, a high pressure is applied to the ink. This is a feature of the shear mode head that discharges ink with extremely minute displacement of the wall on the order of nm.

As described above, the period in which the shear mode head can eject ink is limited to an integral multiple of the time obtained by dividing the length of the ink chamber by the speed of sound in the ink.

In order to discharge at high frequency, it is preferable to shorten the length of the ink groove. Therefore, the shape of the ink groove is a straight groove type having a long shallow groove portion and a shorter groove than the inlet shallow groove type. Is preferred.

Next, the step (4) is an etching catalyst adsorbing step of etching the entire surface of the head to adsorb the electroless plating catalyst. As described above, the ink groove and the air groove are formed in the head, and the resist layer is formed on the upper surface. A method for etching such a head (hereinafter, sometimes referred to as a PZT substrate as needed) to adsorb the electroless plating catalyst includes, for example, the following method. In addition, etching means dissolving one part of the grain boundary of PZT,
To form a crevice-shaped depression on the PZT surface.
The plating metal penetrates deep into the crevasse and precipitates out, so that it serves as an anchor, and the plating film adheres firmly. When PZT is immersed in a 0.5% HBF ₄ and 5% HNO ₃ solution for 3 minutes at room temperature, the grain boundaries of the PZT particles are selectively etched and dissolved, resulting in crevice-shaped depressions on the PZT surface.

The PZT substrate is immersed in a 0.1% aqueous solution of stannous chloride to adsorb stannous chloride, and then immersed in a 0.01% aqueous solution of palladium chloride to adsorb palladium chloride. And a redox reaction (SnCl ₂ + PdCl ₂ → S) between stannous chloride and palladium chloride adsorbed earlier.
nCl ₄ + Pd ↓) to form metallic palladium. This metallic palladium serves as a catalyst for electroless plating.

Next, in step (5), electroless plating is performed on the catalyst-adsorbed surface of the head (PZT substrate) on which the catalyst has been adsorbed.

The electrode metal includes Ni (nickel), Co (cobalt), Cu (copper), Al (aluminum) and the like.
Cu is preferred, and Ni is particularly preferred.

In forming an electrode by electroless plating,
Ni-P plating or Ni-B plating may be used alone, or Ni-P and Ni-B may be overlaid.

In Ni-P plating, the electric resistance increases as the P content increases, so that the P content is preferably about 1 to several percent. Ni−
Since the B content of B plating is usually 1% or less, Ni-P
Ni-B is preferable to Ni-P because the content is large, the electric resistance is low, and the connectivity with external wiring is good.
Since B is expensive, it is also preferable to combine Ni-P and Ni-B.

The thickness of the plating film is preferably in the range of 0.5 to 5 μm. More preferably, it is in the range of 1 to 3 μm.

In the present invention, since the plating resist layer is applied so that the plating metal does not adhere in the above step, plating does not deposit on the resist even when electroless plating is performed.

In order to prevent plating from depositing on the resist, it is more preferable to provide an etching step as a pretreatment for plating. The etching step of the pre-plating process is indispensable to enhance the adhesion of the plating, but at the same time, the resist is oxidized, and thus the electroless plating can prevent the deposition of metal due to the reduction reaction.

Conventionally, as a method for preventing the deposition of plating on the roof portion of the side wall, for example, Japanese Unexamined Patent Application Publication No. 5-26999
The method described in Japanese Patent Publication No. 3 is known. In this method, after grinding the groove in the piezoelectric element, adsorbing the catalyst on the entire head, laminating a photosensitive dry film, exposing with a mask, developing, and covering the roof of the groove side wall with the dry film, There is a method in which the catalyst is adsorbed and electroless plating is performed to remove the dry film. This method requires complicated steps of laminating, exposing, developing, and peeling a photosensitive dry film. However, piezoelectric ceramics,
For example, since PZT is formed from particles having a particle size of several μm, the surface is rough, and a photosensitive dry film cannot adhere to the surface, and the laminate is peeled off during processing, which is likely to cause a masking defect.

Further, Japanese Patent Application Laid-Open No. 8-26769 discloses that
Grind the groove on the piezoelectric element, laminate the photosensitive dry film, mask exposure, develop, cover the roof of the groove side wall with the dry film, adsorb the plating catalyst, peel off the dry film, A method for electroless plating is disclosed. The catalyst is adsorbed not only in the grooves but also on the dry film, so if the metal deposits on the dry film, the dry film that the catalyst has adsorbed is removed to prevent the dry film from being unable to peel off. And then plating. However, when the dry film is peeled off with an alkali or an organic solvent, the sensitive plating catalyst may be deactivated, and the plating is not stable, which is not preferable.
Further, complicated steps such as lamination of a dry film, mask exposure, and development peeling are required.

In the present invention, the groove is ground after the plating resist is spin-coated on the piezoelectric element plate, so that the roof on the side wall of the groove is automatically masked. If the plating resist is oxidized in a pre-treatment etching step, electroless plating is a reduction reaction, so that plating does not deposit on the plating resist, and there is no need to remove the resist before plating. The plating resist can be easily peeled off with an alkali after plating, as described later. Further, since the plating resist is coated on the piezoelectric element plate, unlike the laminated dry film, it does not peel off during pretreatment or plating. Further, troublesome operations such as mask exposure and development are not required.

Further, according to the present invention, since the electroless plating is performed before the groove is covered, the generated hydrogen can be easily removed and the plating can be performed uniformly.

Next, the step (6) is a step of removing the plating resist layer with alkali after plating. Caustic soda is used as the alkali used in this step.

Next, the step (7) is a step of removing the plating film on the front wall 5 of the head 1. To remove the plating deposited on the front wall, use a regular polishing machine or
It may be removed by ultrasonic polishing or electric discharge machining.

An example of a method of polishing and removing the plating metal deposited on the front wall 5 of the head 1 will be described.
Use "High Plus Wrapping Machine" manufactured by Nippon Engis. The plated head is placed on a ceramic sample attachment plate and fixed with wax. This is placed on a rotating lapping plate, and the front wall of the head is polished for 3 minutes while spraying a 3 μm diamond slurry to remove deposited metal.

When a plating film, for example, a nickel film is removed by such polishing, a head (piezoelectric element plate) having no electrodes on the upper surface and the front wall of the head 1 is obtained.

Next, the step (8) is an electrodeposition step of electrodepositing an organic insulating film on the plating film formed in the electroless plating step.

The method for forming the organic insulating film includes an electrodeposition method and a coating method. In the coating method, a polymer film may be spin-coated or conformally coated on the electrode. Since it is coated, troublesome masking is required. In addition, a method of forming an organic film by a dry method, for example, parylene conformal coating requires a large-scale vacuum device, evaporator, and heating device.

The present invention employs an electrodeposition method as an excellent method free from defects such as a coating method and a dry method. In the electrodeposition method, a film is formed only in a place having conductivity, and once a thin film is formed, the place is insulated and the conductivity is lost, so it does not precipitate any more in that place, Since deposition is performed by searching for another conductive place, there is an effect that a uniform thin film can be coated even on a complicated shape. As described above, electrodeposition is preferable because an organic thin film can be easily formed uniformly to the bottom of a fine groove.

According to the present invention, an organic insulating thin film is formed on a plating film by an electrodeposition method.
There is an advantage that electrodeposition can be performed as it is after plating.

As a method of forming an organic insulating film by electrodeposition, for example, a PZT having electrodes formed thereon is immersed in an electrodeposition solution containing a 15% concentration of aminoacrylic resin at room temperature, and a DC voltage of 50 V is applied. Is applied for 2 minutes, a pinhole-free insulating film having a thickness of about 2 μm is formed.

In the present invention, the effects of forming the organic insulating film will be further described as follows. That is, in the present invention, a method is adopted in which a voltage is applied to the electrode on the ink groove side and the electrode on the air groove side is grounded to drive the electrode. There is a need to. In the insulation of such an electrode, compared to coating the surface of the electrode with a hard and easily peelable inorganic film,
The organic insulating film is preferred because it is flexible, hard to peel off, and has waterproofness. Therefore, when an organic insulating film is provided on the electrode, there is an effect that the ink can be ejected using either a water-based ink or a solvent-based ink.

Next, in the step (9), as shown in FIGS. 5 and 6, a part of the plating film on the rear wall 6 and the bottom surface 7 of the head 1 is removed by laser, and This is a step of forming a head wiring 8 continuous with the bottom surface 7.

In the case of electroless plating, the surroundings are good, so that the metal is uniformly deposited along the irregularities on the head surface.
However, in order to drive the electrodes of each groove independently from the outside, it is necessary to make the electrodes of each groove independent and connect a wiring to the electrodes so that signals can be exchanged with the outside. For this reason,
In the present invention, the plating on the front wall of the head is removed in the step (7), and further, in the step (9), a part of the plating film on the rear wall 6 and the bottom surface 7 of the head 1 is irradiated with a laser. By removing, the head wiring 8 which continues from the rear wall 6 to the bottom surface 7 is formed.

The laser removal conditions include the laser wavelength,
Depending on the pulse rate, an energy density of about 50 J / cm ² is required to remove the Ni plating of about 2 μm thickness.

For example, the second harmonic light of the YAG laser focused on the surface to be processed to about 40 μm square is irradiated while sending the workpiece at a pulse energy of 0.4 mJ, a pulse rate of 3 KHz, and a feed step of 20 μm. By doing so, plating is removed and insulation can be secured.

In this case, the irradiation energy density on the surface of the workpiece is 0.4 mJ / (0.004 cm × 0.002
cm) = 50 J / cm ² .

Next, in the step (10), as shown in FIG. 5, a top plate 9 is provided on the upper surface of the head 1, a nozzle plate 10 is provided on the front wall 5 of the head 1, and a rear wall of the head 1 is provided. 6 is a step of joining the manifolds 11 to each other.

Next, in the step (11), as shown in FIG. 6, a head wiring 8 continuous from the rear wall 6 to the bottom surface 7 is connected to a flexible printed cable (ACF) 12 through an anisotropic conductive film (ACF) 12. FPC) 13. In FIG. 6, for convenience, the front wall 5 to which the nozzle plate 10 is joined is shown.
The side is shown to be the near side in the figure.

In the above process, the electrodes of each groove are made independent.
Wiring connected to these electrodes may be formed on the rear wall of the head and the back surface of the head using a plating metal, and connected to the flexible printed cable (FPC) 13 on the back surface by an anisotropic conductive film (ACF) 12.

Further, it is preferable that the flexible printed cable (FPC) 13 is connected to a drive IC (not shown), and the drive circuit can drive the shear mode head.

Next, the second invention of the present invention will be described.

In the first invention, after the plating is deposited, the metal is removed by laser except for the rear wall and the bottom surface of the head except for the head wiring portion. In the second invention, the rear wall 6 of the head 1 is removed. The difference is that the catalyst is irradiated with a laser to deactivate the catalyst other than the head wiring portion 8 on the bottom surface 7.

Removal of a hard metal requires high energy, and therefore, after adsorbing the catalyst and before electroless plating, deactivate the adsorbed catalyst at a place where plating is difficult to deposit and then perform plating. It adopts a method.

When laser irradiation is performed at the catalyst stage,
It is possible to deactivate the catalyst at an energy density of 5 J / cm ² or less, which is about one digit smaller than that of the first invention.

For example, the second harmonic light of the YAG laser focused on the surface to be processed into about 40 μm square is irradiated while sending the workpiece at a pulse energy of 0.04 mJ, a pulse rate of 3 KHz, and a feed step of 20 μm. By doing so, plating was removed and insulation was secured.

In this case, the irradiation energy density on the surface of the workpiece is 0.04 mJ / (0.004 cm × 0.00
2 cm) = 5 J / cm ² .

Therefore, if laser irradiation is performed at the catalyst stage, it is possible to form a plating pattern with an energy density of 5 J / cm ² or less.

[0087]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

Example 1 A thickness of 150 μm (PZT plate 1) and a thickness of 900 μm (PZT plate 1)
Polarize the two PZT plates of plate 2). Polarization is 150 ° C
Immersed in insulating oil and applied with a DC voltage of 10 KV.

Next, the two PZT plates are bonded with an epoxy adhesive so that the polarization directions are opposite. The thickness of the adhesive layer after curing is 5 μm.

The thinner side of the bonded composite PZT board is called the “front side”, and the thicker side is called the “back side”.

On the surface of the composite PZT plate, “plating resist, AH79” manufactured by World Metal Co., Ltd. was diluted twice with butyl cellosolve and spin-coated so as to have a dry film thickness of 5 μm.

Cure in an oven at 100 ° C. for 30 minutes.

From the surface of the composite PZT plate, using a diamond blade, an ink groove having a width of 70 μm and a depth of 300 μm extending in the front-rear direction and a width of 70 μm extending in the front-rear direction.
Air grooves having a depth of 300 μm and a depth of 300 μm are alternately ground at intervals of 70 μm.

Next, ultrasonic cleaning is performed to remove grinding dust, and Ni electroless plating is performed.

In the electroless plating method, a PZT
A plate was degreased by heating to 50 ° C., “PT-0” manufactured by World Metal Co., Ltd. (organic acid salt 0.4% + inorganic alkali salt 0.2% + nonionic activator 0.5%, pH = 1) ), 3
Wash for 0 seconds. After washing with water, etching solution, Co., Ltd.
3 for World Metal "PT-1" (5% inorganic salt + 4% ammonium sulfate, 1.5% fluorine salt, pH = 2)
Soak for 0 seconds. After washing with water, the oxidizing solution, "PT-2" manufactured by World Metal Co., Ltd. (organic acid salt 15% + inorganic salt 2%, pH
= 1) for 30 seconds. After washing with water, a stannous chloride solution, "PT-3" manufactured by World Metal Co., Ltd. (organic acid salt 0.4% + inorganic acid salt 0.8% + stannous chloride 0.6% + Na
Soak in 3.5% Cl, pH = 1) for 30 seconds. Lightly washed with water and immersed in a palladium chloride solution "PT-4" (1% organic acid salt + 3% inorganic acid salt + 0.1% palladium chloride, pH = 1, manufactured by World Metal Co., Ltd.) for 45 seconds. After washing with water
Repeat "PT-3" and "PT-4" again.

The sample after the pretreatment was heated at 80 ° C. in a nickel-phosphorus electroless plating solution “Linden 202H” manufactured by World Metal Co., Ltd.
When plating is performed for 10 minutes while the head is oscillated at a speed of 2.5 cm / sec for 10 minutes with a solution to which "5" is added, a plating film of 1.5 μm is deposited.

Next, the head is immersed in a 5% NaOH solution to remove the plating resist.

Next, the front wall of the plated head is fixed on a ceramic sample mounting plate with the front wall facing upward. This is placed on a rotating lapping plate of a high-plus lapping machine manufactured by Nippon Engis Co., Ltd., and the front wall of the head is polished for 3 minutes while spraying a 3-micron diamond slurry to remove plating metal.

Then, the head was treated with an electrodeposition solution containing 15 wt% aminoacrylic resin, "AE-4K" manufactured by Shimizu Corporation.
X ", apply ultrasonic waves to replace the water at the bottom of the groove with the electrodeposition solution, and apply 50 V DC for 2 minutes at room temperature. After that, the electrodeposition liquid was washed with high-pressure water of 20 kg / cm ² to remove the electrodeposition liquid in the groove, and preliminarily dried at 100 ° C.
Cure at 20 ° C. for 20 minutes.

Subsequently, the plating metal deposited on the rear wall and the bottom surface, except for the wiring portion, is removed with a YAG laser having a wavelength of 532 nm at an energy density of about 50 J / cm ² . Specifically, Y focused on a surface to be processed to about 40 μm square,
Step 2 of sending the second harmonic light of the AG laser at a pulse energy of 0.4 mJ, a pulse rate of 3 KHz, and
Irradiation is performed while feeding the workpiece at 0 μm to remove the plating.

Next, the top plate is bonded. Unpolarized thickness
Apply an adhesive to the same PZT plate as the 5 mm piezoelectric element plate,
The composition is cured for 30 minutes by applying a pressure of 14 to 20 kg / cm ² and a temperature of 90 to 100 ° C.

Using an excimer laser having 128 nozzles having a diameter of 18 μm, a perforated 125 μm polyimide sheet is adhered to the front wall of the head with an epoxy adhesive, and cured at 80 ° C. for 40 minutes.

Next, a manifold formed by injection molding a polyetherimide resin is adhered to the rear wall with an epoxy adhesive.

The head wiring is made of an anisotropic conductive film (AC
By using F), at about 170 ° C. for about 20 seconds, about 14 kg is uniformly applied and heated and pressed to electrically connect to a flexible printed circuit provided on the drive control board.

Embodiment 2 This embodiment is an embodiment in which, in the embodiment 1, after the plating catalyst is adsorbed, the plating catalyst adsorbed to portions other than the wiring forming portions on the rear wall and the bottom surface is removed by laser. This embodiment has the effect that the process is simpler than in the first embodiment.

The thickness of 150 μm (PZT plate 1) and the thickness of 90
Polarize two PZT plates of 0 μm (PZT plate 2). Polarization is performed by immersing in insulating oil heated to 150 ° C. and applying a DC voltage of 10 KV.

Next, the two PZT plates are bonded with an epoxy adhesive so that the polarization directions are opposite. The thickness of the adhesive layer after curing is 5 μm.

On the surface of the composite PZT plate, “plating resist, AH79” manufactured by World Metal Co., Ltd. was diluted twice with butyl cellosolve, and spin-coated to a dry film thickness of 5 μm.

Cure in an oven at 100 ° C. for 30 minutes.

From the surface of the composite PZT plate, using a diamond blade, an ink groove having a width of 70 μm and a depth of 300 μm, extending in the front-rear direction, and a width of 70 μm extending in the front-rear direction.
Air grooves having a depth of 300 μm and a depth of 300 μm are alternately ground at intervals of 70 μm.

Then, ultrasonic cleaning is performed to remove grinding dust, and Ni electroless plating is performed.

In the electroless plating method, a groove is ground, and PZT
A plate was degreased by heating to 50 ° C., “PT-0” manufactured by World Metal Co., Ltd. (organic acid salt 0.4% + inorganic alkali salt 0.2% + nonionic activator 0.5%, pH = 1) ), 3
Wash for 0 seconds. After washing with water, etching solution, Co., Ltd.
3 for World Metal "PT-1" (5% inorganic salt + 4% ammonium sulfate, 1.5% fluorine salt, pH = 2)
Soak for 0 seconds. After washing with water, oxidizing solution, manufactured by World Metal Co., Ltd., "PT-2" (organic acid salt 15% + inorganic salt 2%, p
H = 1) for 30 seconds. After washing with water, stannous chloride solution, “PT-3” (World Organic Co., Ltd.) (organic acid salt 0.4% + inorganic acid salt 0.8% + stannic chloride 0.6% + Na
Soak in 3.5% Cl, pH = 1) for 30 seconds. After gently washing with water, it is immersed in a palladium chloride solution, "PT-4" manufactured by World Metal Co., Ltd. (organic acid salt 1% + inorganic acid salt 3% + palladium chloride 0.1%, pH = 1) for 45 seconds. After washing with water
"PT-3" and "PT-4" are repeated once.

Up to this point, the process is the same as that of the first embodiment. After that, the plating catalyst adsorbed on the portion other than the rear wall and the bottom wiring forming portion of the pretreated sample is removed by laser. More specifically, YAG focused on a surface to be processed to about 40 μm square is used.
The second harmonic light of the laser is converted to a pulse energy of 0.0
4mJ, pulse rate 3KHz, feed step 20μ
Irradiation while feeding the workpiece with m.

This sample was heated to 80 ° C., a head obtained by adding a surfactant “AP555” to a nickel-phosphorus electroless plating solution “Linden 202H” manufactured by World Metal Co., Ltd. for 10 minutes. 2.5cm / sec vertically
When the plating is performed while rocking at a speed of 1.5 mm, a plating film of 1.5 μm is deposited.

Next, the plating solution is removed by washing with water.

Next, the head is immersed in a 5% NaOH solution to remove the plating resist.

The head was immersed in an electrodeposition solution containing 15% by weight of an aminoacrylic resin, "AE-4KX" manufactured by Shimizu Co., Ltd., and ultrasonic waves were applied to remove the water at the bottom of the groove with the electrodeposition solution. Replace and apply 50V DC for 2 minutes at room temperature. Then 2
After washing with high-pressure water of 0 kg / cm ² to remove the electrodeposition solution in the groove and pre-drying at 100 ° C.,
Let cure for 0 minutes.

Then, the front side of the plated head is fixed on a ceramic sample mounting plate with the front wall facing upward. This is placed on a rotating lapping plate of a high-plus wrapping machine manufactured by Nippon Engis Co., Ltd., and the front wall of the head is polished for 3 minutes while spraying diamond slurry of 3 microns to remove plating metal.

Next, the top plate is bonded. Unpolarized thickness
Apply an adhesive to the same PZT plate as the 5 mm piezoelectric element plate,
The composition is cured for 30 minutes by applying a pressure of 14 to 20 kg / cm ² and a temperature of 90 to 100 ° C.

A perforated 125 μm polyimide sheet is adhered to the front wall of the head with an epoxy adhesive using an excimer laser having 128 nozzles having a diameter of 18 μm, and cured at 80 ° C. for 40 minutes.

Next, the manifold formed by injection molding the polyamide resin is adhered to the rear wall with an epoxy adhesive.

The head wiring is made of an anisotropic conductive film (AC
By using F), at about 170 ° C. for about 20 seconds, about 14 kg is uniformly applied and heated and pressed to electrically connect to a flexible printed circuit provided on the drive control board.

[0123]

According to the present invention, the above-mentioned effects can be exerted. In particular, compared with the conventional dry method technology, the bubble removal property is excellent by a very simple wet method technology and a low cost method, It is possible to provide a method of manufacturing a high-performance shear mode head that has a high driving frequency, generates less heat, and can discharge both water-based ink and solvent-based ink.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a process of the present invention.

FIG. 2 is a perspective view showing an example of the process of the present invention.

FIG. 3 is a perspective view showing an example of the process of the present invention.

FIG. 4 is a perspective view showing an example of a process of the present invention.

FIG. 5 is a perspective view showing an example of a process of the present invention.

FIG. 6 is a perspective view showing an example of a process of the present invention.

[Explanation of symbols]

 1: head 1a, 1b: piezoelectric element plate 2: plating resist layer 3: ink groove 4a, 4b: air groove 5: front wall 6: rear wall 7: bottom surface 8: wiring section 9: top plate 10: nozzle plate 11 : Manifold 12: ACF 13: FPC

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Minoru Yamada 1 Sakuracho, Hino-shi, Tokyo Konica Corporation F-term (reference) 2C057 AF01 AF51 AF80 AF93 AG12 AG45 AG89 AP22 AP23 AP24 AP33 AP55 AP57 AP58 BA14

Claims (4)

[Claims] 1. A method for manufacturing a shear mode head, comprising the following steps (1) to (11) in order. (1) Step of joining two polarized piezoelectric element plates with their polarization directions opposite to each other to form a cuboid or cubic head (2) Step of applying a plating resist layer on the upper surface of the head (3) Forming ink grooves and air grooves extending in the front-rear direction on the upper surface side of the head, and alternately arranging the ink grooves and air grooves. (4) Etching the entire surface of the head to remove the electroless plating catalyst. (5) Electroless plating step of electroless plating on the catalyst adsorption surface (6) Step of removing plating resist layer with alkali (7) Polishing the front wall of the head to form a plating film Removing step (8) electrodeposition step of electrodepositing an organic insulating film on the plating film formed in the electroless plating step; (9) removing part of the plating film on the rear wall and bottom surface of the head by laser; The back wall Forming a continuous head wiring on the bottom surface; (10) bonding a top plate to the top surface of the head, a nozzle plate to the front wall of the head, and a manifold to the rear wall of the head; (11) the rear wall Of connecting the continuous head wiring from the bottom to the flexible printed cable (FPC) via an anisotropic conductive film (ACF) 2. A method for manufacturing a shear mode head, comprising the following steps (1) to (10) in order. (1) Step of joining two polarized piezoelectric element plates with their polarization directions opposite to each other to form a cuboid or cubic head (2) Step of applying a plating resist layer on the upper surface of the head (3) Forming ink grooves and air grooves extending in the front-rear direction on the upper surface side of the head, and alternately arranging the ink grooves and air grooves. (4) Etching the entire surface of the head to remove the electroless plating catalyst. (5) a step of irradiating a laser to a catalyst other than a head wiring portion on the rear wall and bottom surface of the head to deactivate the catalyst; and (6) an electroless plating on a catalyst adsorption surface remaining on the head. Electroplating step (7) Step of removing plating resist layer with alkali (8) Electrodeposition step of electrodepositing an organic insulating film on the plating film formed in the electroless plating step (9) Fixing the front wall of the head Polishing (10) bonding a top plate to the top surface of the head, a nozzle plate to the front wall of the head, and a manifold to the rear wall of the head (11) continuous from the rear wall to the bottom surface To connect a flexible printed cable (FPC) through an anisotropic conductive film (ACF) 3. The method according to claim 1, wherein in the step (3), both side walls of the ink groove are ground in a direction perpendicular to an upper surface of the head and are ground in parallel with each other. Manufacturing method of shear mode head. 4. The flexible printed cable (FP)
4. The method according to claim 1, wherein C) is connected to a drive IC.