JP3587078B2 - Method of manufacturing inkjet head - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an ink jet head for an ink jet recording apparatus in which ink droplets are ejected only when recording is required and adheres to a recording paper surface.
[0002]
[Prior art]
The ink jet recording apparatus has many advantages such as extremely low noise at the time of recording, high-speed printing, and the use of inexpensive plain paper with high ink flexibility. Among them, the so-called ink-on-demand method, which discharges ink droplets only when printing is necessary, is currently the mainstream because it does not require collection of ink droplets unnecessary for printing.
[0003]
In the ink-on-demand type recording, the ink-jet head recording apparatus includes an ink-jet head recording apparatus (JP-A-6-71882) that uses electrostatic force as a driving unit as a method of ejecting ink. Has the advantages of small size, high density, high printing quality and long life.
[0004]
In this ink jet recording apparatus, the diaphragm of the ink jet head is formed by etching the Si substrate. Japanese Unexamined Patent Publication No. 9-234873, page 7 discloses that one side of the Si substrate has a predetermined thickness. A high-concentration p-type impurity layer is formed, Si is etched from the other surface of the Si substrate to leave the high-concentration p-type impurity layer, and etching is stopped to form the diaphragm with high accuracy. A method for manufacturing an ink jet head including steps is disclosed. This etching stop technique utilizes the fact that the etching rate of the P-type impurity layer is extremely low.
[0005]
[Problems to be solved by the invention]
However, although it has become possible to form the diaphragm with high accuracy in the above-described method of manufacturing the diaphragm of the inkjet head, the demand for further downsizing and high accuracy of the inkjet head has increased, and a further higher diaphragm has been required. Thickness accuracy has become necessary.
[0006]
Therefore, the present invention has been made to solve the above-described problem, and an object of the present invention is to provide a diaphragm having higher accuracy in response to a demand for downsizing and higher accuracy of an inkjet head. It is an object of the present invention to provide a method for manufacturing an inkjet head.
[0007]
[Means for Solving the Problems]
Method of manufacturing an ink jet head according to claim 1, the configuration and the plurality of nozzle holes for ejecting ink droplets, made of Si substrate, a discharge chamber connected to each of the nozzle holes, at least one wall of the discharge chamber When manufacturing an inkjet head having a vibrating plate and a driving unit that causes deformation of the vibrating plate, a high-concentration p-type impurity layer having a predetermined thickness is formed on one surface of the Si substrate. A method of manufacturing an ink jet head, comprising: forming the diaphragm with high precision by etching the Si substrate from the other surface of the Si substrate to leave the high-concentration p-type impurity layer and stop etching. Forming the vibration plate, patterning an oxide film on a surface of the high-concentration p- type impurity layer opposite to the other surface, and sandwiching the oxide film with the high-concentration p- type impurity. An Au layer is formed so as to be in contact with the layer, and the etching is stopped by using an electrochemical etching stop method. Therefore, the etching rate of the high-concentration p-type impurity can be further reduced, and a diaphragm with higher accuracy can be formed. As a result, an ink jet head having excellent print quality can be manufactured. This has the effect. The electrochemical etching stop method is a technique for suppressing etching by utilizing the fact that the potential at which the Si surface is anodized is higher in p-type Si than in n-type Si. When a potential is applied such that only the p-type Si layer is anodically oxidized by attachment or the like, an oxide film is formed on the surface, the p-type layer is protected from etching, and an etching stop utilizing the phenomenon that the p-type Si layer remains as a Si thin film. Technology.
[0008]
In the method of producing an ink jet head according to claim 1, after forming the Au layer in contact with the high-concentration p-type impurity layer, have preferably be etched stop in combination with electrochemical etch stop technique . If an Au layer is formed so as to be in contact with the high-concentration p-type impurity layer and then the etching is stopped by using an electrochemical etching stop method, the electrochemical etching can be performed without applying a potential from an external power supply. You can stop. The electrochemical etching stop technique itself using the Au layer is disclosed in TRANSDUCERS '97703.
[0009]
In the method of manufacturing an ink jet head according to claim 1 , in the step of forming the diaphragm, etching of Si is performed using a low-concentration aqueous solution of potassium hydroxide (claim 2 ), or high-concentration p-type. Etching of Si up to the vicinity of the impurity layer is performed using a high-concentration potassium hydroxide aqueous solution, and etching from the vicinity of the high-concentration p-type impurity layer to the high-concentration p-type impurity layer is performed with a low-concentration potassium hydroxide aqueous solution. (Claim 3 ) is preferred. In the former case, the etching using a low-concentration potassium hydroxide aqueous solution can ensure the etching stop effect in the high-concentration p-type impurity layer and form the diaphragm with higher precision. In the latter case, the roughness of the diaphragm surface can be reduced by using etching using high-concentration potassium hydroxide in combination. In addition, while etching with high-concentration potassium hydroxide increases the overall etching rate, subsequent etching with low-concentration potassium hydroxide aqueous solution ensures an etching stop effect in the high-concentration p-type impurity layer. In addition, the diaphragm can be formed with higher accuracy.
[0010]
In the method for manufacturing an ink jet head according to claim 3 , it is preferable that the concentration of the low-concentration aqueous potassium hydroxide solution is 0.5 to 20% by weight (claim 4 ). Within this concentration range, the effect of lowering the etching rate with high-concentration p-type impurities can be obtained.
[0011]
In the method of producing an ink jet head according to claim 4, the concentration of the high concentration aqueous solution of potassium hydroxide is preferably 30~55wt% (claim 5). Within this concentration range, a sufficient effect of reducing the roughness of the etched surface is selected.
BEST MODE FOR CARRYING OUT THE INVENTION
(Example 1)
FIG. 1 is an exploded perspective view of an ink jet head according to a first embodiment of the present invention, which is partially shown in a sectional view. This embodiment shows an example of a face ink jet head for discharging ink droplets from nozzle holes provided on a surface portion of a substrate. FIG. 2 is a side sectional view of the assembled overall device, and FIG. 3 is a view taken along line AA ′ of FIG. The ink jet head of this embodiment has a laminated structure in which three substrates 1, 2, and 3 having a structure described in detail below are stacked and joined.
[0013]
The intermediate first substrate 1 is a Si substrate, and has a concave portion 7 for forming a discharge chamber 6 having a bottom wall as a vibration plate 5 and an orifice 8 provided at a rear portion of the concave portion 7. And a concave portion 11 which forms a common ink cavity 10 for supplying ink to each ejection chamber 6. In addition, a slope 20 is formed in the connecting portion 19 between the partition 18 and the diaphragm 5. An oxide film having a thickness of 0.1 μm is formed on the entire surface of the first substrate by thermal oxidation to form an insulating film. This is to prevent dielectric breakdown and short circuit during ink jet driving.
[0014]
The second substrate 2 bonded to the lower surface of the first substrate 1 is made of borosilicate glass, and a recess 14 for mounting the electrode 15 on the first substrate 1 is etched by 0.3 μm. A gap G is formed between the diaphragm 5 and the electrode 15 disposed opposite thereto, that is, a gap G. The concave portion 14 is formed in a slightly larger shape similar to the shape of the electrode portion so that the electrode 15, the lead portion 16 and the terminal 17 can be mounted therein. The electrodes are formed by sputtering ITO 0.1 μm in the recesses 14 to form an ITO pattern. Therefore, the gap G after the anodic bonding of the first substrate 1 and the second substrate 2 in this embodiment is 0.2 μm.
[0015]
Further, as the third substrate 3 bonded to the upper surface of the first substrate, an Si substrate having a thickness of 100 μm is used, and nozzles are formed on the surface of the substrate 3 so as to communicate with the recesses 7 for the discharge chambers 6. A hole 12 is provided, and an ink supply port 13 is provided so as to communicate with the concave portion 11 for the ink cavity 10.
[0016]
The operation of the inkjet head configured as described above will be described. When a pulse electrode of 0 V to 35 V is applied to the electrode 15 by the transmission circuit 23 and the surface of the electrode 15 is positively charged, the corresponding lower surface of the diaphragm 5 is charged to a negative potential. Therefore, the diaphragm 5 bends downward due to the electrostatic attraction. Next, when the electrode 15 is turned off, the diaphragm 5 is restored. Therefore, the pressure in the ejection chamber 6 rises sharply, and the ink droplets 21 are ejected from the nozzle holes 12 toward the recording paper 22. Next, the diaphragm 5 bends downward again, so that ink is supplied from the ink cavity 10 into the ejection chamber 6 through the orifice 8. The connection between the substrate 1 and the transmission circuit 23 is made in an oxide film window (not shown) opened in a part of the substrate 1 by dry etching. The ink is supplied to the ink jet head through an ink supply port 13 at the end of the ink cavity 10.
[0017]
As for the method of manufacturing the ink jet head according to the first embodiment of the present invention, the method of manufacturing the first substrate 1 will be described with reference to FIG. 4 showing the diffusion process of the first substrate, FIGS. The case of forming a 2-micron-thick diaphragm using B ₂ O ₃ as an impurity diffusion source in the first substrate etching process diagram will be described in detail.
[0018]
The diaphragm in the ink jet head of this embodiment is a Si thin film in which p-type impurities are diffused at a high concentration. This Si thin film utilizes the fact that the etching rate in the Si etching using an alkaline aqueous solution is extremely small in a high concentration (about 5 × 10 ¹⁹ cm ⁻³ or more) region when the dopant is boron. It is made. That is, when forming the discharge chamber and the ink cavity by the alkali anisotropic etching, the etching rate becomes extremely small when the boron-doped layer is exposed. Thereby, the diaphragm is manufactured to have a desired thickness.
[0019]
First, both surfaces of a Si substrate 41 having a plane orientation of (110) are mirror-polished to produce a substrate having a thickness of 140 microns (FIG. 4A). The Si substrate 41 is set in a thermal oxidation furnace, and subjected to a thermal oxidation treatment in an atmosphere of oxygen and water vapor at 1100 ° C. for 4 hours to form an oxide film 42 of 1.2 μm on the surface of the Si substrate 41 (FIG. 4). (B)). Next, in order to remove the oxide film 42 on the surface 43 on which the boron-doped layer is formed, a resist is coated on the surface 44 of the Si substrate 41 opposite to the surface 43 on which the boron-doped layer is formed, and a boron-doped layer is formed using the resist as a protective film. The oxide film 42 on the surface 43 is removed by etching with a hydrofluoric acid aqueous solution, and the resist is stripped (FIG. 4C). A diffusion agent 45 in which 3.15 wt% of B ₂ O _{3 serving} as a diffusion source is dispersed in an organic solvent is spin-coated on the surface 43 on which the boron-doped layer from which the oxide film has been removed at 2,000 rpm for 1 minute, and clean. Bake in an oven at a temperature of 140 degrees Celsius for 30 minutes (FIG. 4D). At this time, the thickness of the diffusing agent 45 is 1.2 microns.
[0020]
The Si substrate 41 coated with the diffusing agent 45 is set in a thermal oxidation furnace, and heated in an oxygen atmosphere at 600 ° C. to oxidize and remove the organic binder in the diffusing agent 45 and bake B ₂ O ₃ . Subsequently, the inside of the furnace is set to a nitrogen atmosphere, the temperature is increased to 1100 degrees Celsius, the temperature is maintained for 12 hours, and boron is diffused into the Si substrate to form a boron doped layer 46. At this time, a boron compound 47 is formed at the interface between the diffusing agent 45 (B ₂ O ₃ ) and the boron doped layer 46 on the surface of the Si substrate 41 (FIG. 4E).
[0021]
A resist is coated on the side opposite to the surface on which the boron doped layer 46 is formed, and the diffusing agent 45 is removed by etching with a hydrofluoric acid aqueous solution (FIG. 4F). Since the boron compound 47 appearing on the surface of the Si substrate 41 has high etching resistance and cannot be removed by wet etching, the following means is employed. First, after the resist of the Si substrate 41 is stripped, the Si substrate 41 is set in an oxidation furnace, and the boron compound 47 is oxidized for 1 hour under the conditions of oxygen and water vapor at 600 degrees Celsius, and can be etched with a hydrofluoric acid aqueous solution. It is chemically changed to B ₂ O ₃ + SiO ₂ . Since the oxidation temperature is low, the diffusion does not proceed, and the boron compound 47 can be removed by dry etching without being oxidized. The boron compound 47 on the diffusion surface is oxidized and chemically changed to B ₂ O ₃ + SiO ₂ and further thermally oxidized to form an oxide film 48 of 1.2 μm on the boron doped layer side (FIG. 4 (g)). .
[0022]
The above is the case where the high-concentration boron-doped layer 46 is formed by the coating method. As another means for forming the high-concentration boron-doped layer, there is a method in which a boron diffusion plate is opposed to a Si substrate to perform thermal diffusion. .
[0023]
Next, as a method of forming an Au layer on the surface of the Si substrate 41, a method of forming an Au layer on the entire surface of the Si substrate 41 on the side of the boron doped layer 46 in FIG. The case where the Au layer is formed so that the Au layer contacts a part of the surface on the 46 side will be described in detail.
[0024]
First, when forming an Au layer on the entire surface of the boron-doped layer 46 side, the surface 44 of the Si substrate 41 (FIG. 5A) having an oxide film formed on both surfaces in the diffusion step is opposite to the surface on which the boron-doped layer is formed. Then, a resist coat and resist patterning for forming the ejection chamber 6 and the ink cavity 10 are performed. Then, the oxide film 42 is patterned by etching with a buffered hydrofluoric acid aqueous solution (FIG. 5B). At this time, the oxide film 44 on the side of the boron doped layer 46 of the Si substrate 41 is completely removed, and the surface of the boron doped layer 46 is exposed. The Si substrate 41 is washed with an RCA cleaning solution (ammonia: hydrogen peroxide: water = 1: 4: 20), washed well with water, dried with an IPA drier, and then set on a sputtering device. The Au layer 51 is formed by sputtering, and in order to enhance the adhesion between the Au layer 51 and the Si substrate 41, a Cr layer (not shown) is sputtered with a thickness of 100 Å, and then the Au layer 51 is formed by 1 μm. (FIG. 5C).
[0025]
Next, in the case where the Au layer is formed so that the Au layer contacts the boron doped layer 46 of the Si substrate 41, the Si substrate 41 (FIG. 6A On the surface 44 opposite to the surface on which the boron-doped layer is formed, a resist coat and a resist pattern for forming the patterning of the ejection chamber 6 and the ink cavity 10 are applied. At the same time, the resist patterning is performed so that the opposite side of the oxide film 61 located at the portion to become the ejection chamber 6 and the ink cavity 10 remains, and is etched with a buffered hydrofluoric acid aqueous solution to pattern the oxide film 42 (FIG. 6B )). The Si substrate 41 is washed with an RCA cleaning solution, washed well with water, dried with an IPA drier, and then a Cr layer (not shown) is sputtered with a thickness of 100 Å, and the Au layer 62 is formed with a 1000 Å film. A thick film is formed (FIG. 6C).
[0026]
Here, the thickness of the Au layer is not so important, and it is important that the Au layer is in contact with the boron-doped layer. However, if the sputtered film of the Au layer is thin, pinholes are likely to be formed, and when the Si substrate 41 is etched with an aqueous potassium hydroxide solution, the underlying Si substrate is etched through the pinholes of the Au layer. Therefore, when the Au layer 51 is formed on the entire surface of the boron-doped layer, the thickness of the Au layer is increased. On the other hand, in the case where the Au layer 62 is formed so as to be in contact with a part of the boron-doped layer, even if there is a pinhole in the Au layer 62, the diaphragm is formed by an intermediate oxide film in an etching step described later. The surface of the part of the boron doped layer is protected. Therefore, it is not necessary to consider protection of the surface of the Si substrate 41 at the time of etching by the Au layer 62, so that the Au layer 62 may be 1000 Å.
[0027]
Subsequently, in FIG. 7, a case where a 1-micron-thick diaphragm is formed by etching a Si substrate with a low-concentration aqueous solution of potassium hydroxide of 3 wt%. The Si substrate 41 (FIG. 7A) on which the oxide film is patterned and on which the Au layer 62 is formed is immersed in a 3 wt% potassium hydroxide aqueous solution. Etching starts from the portion 71 where Si is exposed, and immediately before the etching reaches the boron doped layer, the surface roughness of the etched surface 72 due to the etching becomes 10 μm (FIG. 7B). When the etching reaches the boron-doped layer, the surface roughness of the diaphragm 5 becomes 0.02 μm or less due to the function of the etching stop in the boron-doped layer. Therefore, even if the thickness variation of the initial substrate is 5 microns, the thickness accuracy of the diaphragm becomes 1 ± 0.015 microns, and a highly accurate diaphragm can be formed. Finally, after the etching of the Si substrate 41 with the aqueous potassium hydroxide solution, the Au layer 62 is removed by etching with a potassium iodide aqueous solution, the Cr layer is etched with a cerium ammonium nitrate aqueous solution, and then the oxide film 42 is removed with a hydrofluoric acid aqueous solution. Thus, the first substrate is completed (FIG. 7D).
[0028]
(Example 2)
FIG. 8 is a diagram showing the etching process of the first substrate in FIG. 8 in the case where the etching of the Si substrate according to the second embodiment of the present invention is performed using a 35 wt% aqueous solution of potassium hydroxide and a 3 wt% aqueous solution of potassium hydroxide. Will be described.
[0029]
The Si substrate 41 (FIG. 8A) on which the oxide film 42 is patterned and the Au layer is formed is etched with a 35 wt% aqueous solution of potassium hydroxide, and the etching is performed immediately before reaching the boron-doped layer (remaining about 10 μm). 8 (b)). In the etching with the 35 wt% aqueous solution, etching proceeds from the portion 81 where Si is exposed, and the roughness of the etched surface 82 is suppressed to 1 μm or less. Next, the etching solution is changed to a 3 wt% aqueous solution of potassium hydroxide, and the etching is continuously stopped (FIG. 8C). In the case of the present embodiment, the surface roughness of the etching surface 82 until reaching the boron doped layer 46 is suppressed to one tenth or less as compared with the case where the etching is performed by using only 3 wt% potassium hydroxide aqueous solution. The surface roughness of 83 is theoretically 0.002 μm or less. However, due to the influence of crystal defects in the boron-doped layer 46, the size is actually about 0.01 μm. Therefore, the thickness accuracy of the diaphragm can be reliably increased by using the 35 wt% and 3 wt% aqueous potassium hydroxide solution. Further, in etching with a 35 wt% aqueous solution of potassium hydroxide, side etching in the horizontal direction with respect to the Si substrate is small and the etching dimensional accuracy in the horizontal direction is high. Etching using a 35 wt% and 3 wt% aqueous solution of potassium hydroxide is significant in that the etching rate is high and the etching time can be reduced.
[0030]
Finally, after the etching of the Si substrate 41 with the aqueous potassium hydroxide solution, the Au layer 62 is removed by etching with a potassium iodide aqueous solution, the Cr layer is etched with a cerium ammonium nitrate aqueous solution, and then the oxide film 42 is removed with a hydrofluoric acid aqueous solution. Thus, the first substrate is completed (FIG. 8D).
[0031]
(Example 3)
Regarding the effect of forming the Au layer so as to be in contact with the boron doped layer and the concentration of the low-concentration potassium hydroxide aqueous solution, the case where the Au layer is formed (in the Au contact state) and the case where the Au layer is not (the Au non-contact state) are described. FIG. 9 shows the relationship between the etchant concentration and the etching stop selectivity (the ratio of the etching rate of undoped Si to the etching rate of boron-doped Si).
[0032]
It is desirable that the etching stop selectivity is high. The higher the selectivity, the smaller the surface roughness that occurs before reaching the etching stop and the variation in the initial thickness of the Si substrate can be reduced by the function of the etching stop. As can be seen from FIG. 9, the selectivity tends to increase as the concentration decreases, and the selectivity further increases during Au film formation. For example, in a 3 wt% potassium hydroxide aqueous solution, the selectivity is 60 in the Au non-contact state, whereas the selectivity reaches 500 in the Au contact state, which is more than eight times that in the Au specific contact state. It can be seen that by bringing Au into contact with the high-concentration boron diffusion layer and immersing it in a potassium hydroxide aqueous solution for etching, the same effect as that of a known electrochemical etching stop is obtained.
[0033]
When the diaphragm is formed using only the low-concentration etchant, considering that the surface roughness of the etched surface until reaching the boron doped layer is about 10 microns, the thickness accuracy of the diaphragm should be suppressed to within 0.3 microns. In this case, the selection ratio needs to be at least 16. That is, when the Au layer is formed on the surface of the boron-doped layer (in the Au contact state), it can be said that the concentration of potassium hydroxide should be 20 wt% or less. By the way, the diaphragm thickness accuracy of 0.3 micron here is the worst case. If the accuracy is further improved, the inkjet head can be easily reduced in size and accuracy, and the printing quality can be stabilized. No. On the other hand, when the concentration of the aqueous potassium hydroxide solution is extremely low, the etching ability with respect to Si tends to be unstable, and when the concentration is lower than 0.5 wt%, it is not practical. Therefore, in a state where the Au layer is formed on the surface of the boron-doped layer in the formation of the diaphragm of the inkjet head, the optimal concentration of the low-concentration aqueous potassium hydroxide solution for the purpose of stopping the etching is 0.5 to 10 wt%. By improving the etching stop selectivity by forming the Au layer and suppressing the surface roughness of the diaphragm by the low-concentration potassium hydroxide, an ink jet having stable printing quality could be provided.
[0034]
(Example 4)
The concentration of the high-concentration aqueous potassium hydroxide solution will be described with reference to FIG. 10 showing the relationship between the etching amount and the surface roughness.
[0035]
The major purpose of using a high-concentration aqueous solution of potassium hydroxide as an etching solution is to suppress the surface roughness of the etched surface immediately before reaching the boron doped layer.In selecting the concentration, pay attention to only the surface roughness caused by etching. Good. The surface roughness of the etched surface in a low concentration (0.5 to 20 wt%) aqueous potassium hydroxide solution is 6 μm or more when 170 μm is etched immediately before reaching the boron doped layer, and the surface roughness is reduced by increasing the concentration. I understand. In order to obtain the effect of increasing the concentration, the surface roughness is preferably 30 wt% or more, at which the surface roughness is about half that of the low concentration etching, but the adjustable maximum concentration of the aqueous potassium hydroxide solution is 55 wt%. Therefore, in order to increase the thickness accuracy of the diaphragm and to realize an ink jet head having better printing quality, the optimum concentration of the high-concentration aqueous potassium hydroxide solution used in the initial etching step is 30 to 55 wt%.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing the structure of an inkjet head according to a first embodiment.
FIG. 2 is a sectional side view of the inkjet head according to the first embodiment.
FIG. 3 is a view taken along line AA ′ of FIG. 2;
FIG. 4 is a process chart of diffusion forming a manufacturing process of the first substrate of the inkjet head in the first embodiment.
FIG. 5 is a process diagram of a first example of the Au film forming the manufacturing process of the first substrate of the inkjet head in the first embodiment.
FIG. 6 is a process diagram of a second example of the Au film forming the manufacturing process of the first substrate of the inkjet head in the first embodiment.
FIG. 7 is a process diagram of an etching forming a manufacturing process of the first substrate of the inkjet head in the first embodiment.
FIG. 8 is a process diagram of an etching constituting a manufacturing process of a first substrate of an ink jet head in Embodiment 2.
FIG. 9 is a graph showing the relationship between the aqueous solution of potassium hydroxide and the selectivity in Example 3.
FIG. 10 is a diagram showing a relationship between an etching amount and surface roughness in Example 4.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 2nd board | substrate 3 3rd board | substrate 5 Vibration plate 6 Discharge chamber 7 Depression 8 Orifice 9 Narrow groove 10 Ink cavity 11 Depression 12 Nozzle hole 13 Ink supply port 14 Depression 15 Electrode 16 Lead part 17 Terminal 21 Ink droplets 22 Recording paper 23 Transmission circuit 41 Si substrate 42 Oxide film 43 Surface on which boron doped layer is formed 44 Opposite surface 45 Diffusing agent 46 Boron doped layer 47 Boron compound 48 Oxide film 51 Au layer 61 Oxide film 62 Au layer 71 Si Exposed portion 72 Etched surface 81 Si exposed portion 82 Etched surface

Claims (5)

A plurality of nozzle holes for discharging ink droplets, a discharge chamber made of a Si substrate and connected to each of the nozzle holes, a diaphragm constituting at least one wall of the discharge chamber, and a deformation of the diaphragm. When manufacturing an ink jet head having a driving means for generating the silicon substrate , a high-concentration p-type impurity layer having a predetermined thickness is formed on one surface of the Si substrate, and the Si substrate is removed from the other surface of the Si substrate. in the method for manufacturing an ink jet head including a step of forming the diaphragm with high precision by which etching is performed allowed residual said high concentration p-type impurity layer etched stop, the step of forming the vibrating plate, wherein high concentration and the other surface of the p-type impurity layer by patterning the oxide film on the opposite side, forming a Au layer in contact with the high-concentration p-type impurity layer across the oxide layer, an electrochemical etch Method of manufacturing an ink jet head and performing etching stop in combination with grayed termination method. 2. The method for manufacturing an ink jet head according to claim 1, wherein in the step of forming the diaphragm, Si is etched using a low-concentration aqueous solution of potassium hydroxide . 2. The method for manufacturing an ink jet head according to claim 1, wherein, in the step of forming the diaphragm, etching of the Si up to the vicinity of the high concentration p-type impurity layer is performed using a high concentration potassium hydroxide aqueous solution. A method for manufacturing an ink jet, wherein etching from the vicinity of a p- type impurity layer to the high-concentration p-type impurity layer is performed using a low-concentration potassium hydroxide aqueous solution . 4. The method according to claim 2, wherein the concentration of the low-concentration aqueous potassium hydroxide solution is 0.5 to 20 wt % . 4. The method according to claim 3, wherein the concentration of the high-concentration aqueous potassium hydroxide solution is 30 to 55 wt % .

Images