JP2007216416A - Method for manufacturing inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent warpage and cracking of a substrate, and deformation and cracking of an orifice plate caused by the deflection and cracking when the substrate is made long in the CR fabrication method. <P>SOLUTION: A reinforcing plate with a beam formed therein is bonded with a polyether amide before an ink supplying port is formed, and then, the ink supplying port is formed by an etching process. Lengthening becomes possible by adding the process, and a printing speed can be made fast. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an ink jet recording head in which liquid is ejected from an orifice to form droplets.

  With regard to this type of ink jet recording head, for example, the ink jet recording method described in Patent Document 1 is different from other ink jet recording methods in that thermal energy is applied to a liquid to obtain a driving force for droplet ejection. It has characteristics.

  That is, in the recording method disclosed in the above-mentioned publication, the liquid that has been subjected to the action of thermal energy is superheated to generate bubbles, and droplets are discharged from the orifice at the tip of the recording head by the action force based on the generation of bubbles. It is characterized in that information is recorded by forming the droplets on the recording member.

  A recording head applied to this recording method generally includes an orifice provided for ejecting a liquid, and a heat acting portion that is a portion where heat energy for ejecting droplets communicated with the orifice acts on the liquid. A liquid discharge section having a liquid flow path having a liquid crystal structure as a part, a heating resistance layer as a heat conversion body that is a means for generating thermal energy, an upper protective layer that protects it from ink, and a lower layer for storing heat It has. By the way, as a method of forming high-density, high-precision nozzles and discharge rollers, methods disclosed in Patent Document 2 and Patent Document 3 have been proposed.

Patent Document 4 proposes that a rib structure is provided on the orifice plate above the ink supply portion in the nozzle manufacturing method.
JP 54-51837 A JP-A-5-330066 JP-A-6-286149 Japanese Patent Laid-Open No. 10-146979

  In the manufacturing method of JP-A-6-286149, it has been proposed to increase the width that can be printed at one time in order to increase the printing speed. In order to increase the width that can be printed at one time, it is necessary to arrange the ink discharge lengths longer. If the discharge rolls are arranged long, the ink supply rolls need to be long. When the ink supply rod was opened for a long time, there were the following problems.

1. Substrate distortion caused by opening the ink supply for a long time In particular, in order to reduce the size of the substrate from the viewpoint of cost, it is necessary to reduce the size perpendicular to the printed width of the substrate, as shown in FIG. Since the ink supply rod is formed in the vertical direction and the ink supply roller is processed on the substrate, the substrate itself is distorted and the flatness of the discharge roller cannot be maintained as shown in FIG. .

2. Occurrence of cracks in substrate during chip handling After a batch formation with a wafer or the like, it is divided into discharge elements and flows to the flow path member in a sticking process, but when divided into discharge elements, it becomes an elongated substrate. If a slit-like ink supply rod is formed at the center of the elongated substrate, stress may be applied to the substrate when the substrate is gripped, and the substrate may be broken.

  In particular, when the printing width is large, the length of the discharge element becomes long and the ink supply length becomes long, so that the stress is increased.

  3. Cracking due to deformation of the substrate at the time of joining the flow path member, cracking of the orifice plate due to deformation of the substrate, and ink resistance is required as an adhesive that joins the deformation discharge element to the flow path member, so thermosetting Adhesive is used. In addition, a resin is adopted for the flow path member because of its ease of processing and low cost. When the discharge element is bonded to the flow path member, it is bonded using a thermosetting adhesive. Therefore, when the discharge element and the flow path member return to normal temperature due to the difference in coefficient of thermal expansion, residual stress is generated in the discharge element. To do. Then, the substrate on which the ejection element is formed is broken or the substrate is deformed, and the orifice plate formed thereon is deformed, the ejection direction is bent, and printing may be defective.

  Japanese Patent Laid-Open No. 10-146979 proposes a structure in which ribs are set up to prevent the deformation of the orifice plate. This is to prevent the deformation of the orifice plate when the orifice plate swells. Deformation cannot be suppressed from the size.

In addition, a method of forming a beam as shown in FIG. 11 on the ink supply roller of the substrate can be considered. There are many restrictions such as laminating a dry film and deformation of the mold material at the time of laminating the mold material forming the nozzle to the application process.

  Therefore, a method is adopted in which the ink supply port is formed by anisotropic etching after the step of applying the mold material for forming the nozzle and applying the nozzle material. When the ink supply layer is formed by anisotropic etching, a (100) substrate is generally used as the silicon substrate. However, using the (100) substrate to form a beam has the following problems.

  First, in order to provide a beam on the substrate surface, if a mask having a beam shape is used on the back surface, the beam width is 50 μm, but if the substrate thickness is generally 625 μm, the surface is 950 μm.

  When the beam width is 950 μm, nozzles of 400 μm or more are generated from the discharge port to the ink supply port, the nozzle refill is slowed down, and the frequency characteristics are greatly deteriorated. If the substrate is made thin, the process flow becomes difficult due to problems such as strength.

  Next, it is difficult to provide a beam on the back surface of the substrate using a back surface mask.

  As described above, it has been difficult to provide beams on the ink supply surface on both the front and back surfaces.

  In order to solve the above problems, a method of manufacturing an ink jet recording head in which an ink flow path and an ink discharge roller are provided on a substrate provided with a heating resistor, and ink is discharged by utilizing foaming of ink due to heat generated by the heating resistor. The step of applying and patterning the resin of the mold material for forming the nozzle flow path on the substrate provided with the heating resistor, the step of applying and patterning the resin forming the ink flow path and the ink discharge flow, and the ink supply flow Before the step of etching the substrate for forming the ink supply rod, the step of etching the substrate for forming, the step of removing the resin of the mold material, and the plate provided with the beam for reinforcing the ink supply rod It is characterized in that the subsequent steps of etching the substrate for forming the ink supply rod are flowed while being bonded.

  When a plate having a beam for reinforcing the ink supply rod is bonded after forming the ink supply rod, the orifice plate may be deformed by the warp of the substrate just like the conventional problem immediately after forming the ink supply port. Yes, it is necessary to bond before forming the ink supply roll.

  Therefore, the plate provided with the beam for reinforcing the ink supply roller needs to be resistant to the liquid for etching the ink supply roller.

  When the etching liquid is silicon anisotropic etching, silicon can be used for the plate on which the beam for reinforcing the ink supply is provided. By forming the beam to be reinforced by anisotropic etching, the etching surface can be used for the anisotropic etching solution without changing the shape because the etching rate becomes slow.

  Further, a plate provided with a beam for reinforcing the ink supply port is made of a ceramic material such as alumina so that it is resistant to a silicon etching solution and can be used.

  A material that reinforces the ink supply but adheres the plate provided with the beam is also required to be resistant to the silicon etching solution. In silicon anisotropic etching, the etching solution is an alkaline solution and is exposed to 80 ° C. for 10 hours or more. Therefore, by using the polyether amide of thermoplastic resin, there is adhesiveness and resistance to silicon anisotropic etchant.

  As described above, in a method of manufacturing an ink jet recording head in which an ink flow path and an ink discharge port are provided on a substrate provided with a heating resistor, and ink is ejected by using foaming of ink due to heat generated by the heating resistor. A step of applying and patterning a resin of a mold material for forming a nozzle flow path on a substrate having a heating resistor, a step of applying and patterning a resin forming an ink flow path and an ink discharge flow, and forming an ink supply flow For this purpose, the step of etching the substrate and the step of removing the resin of the mold material are bonded, and the plate provided with the beam for reinforcing the ink supply rod is bonded before the step of etching the substrate for forming the ink supply port. Then, the orifice plate is deformed by the warp of the substrate by flowing the subsequent steps of etching the substrate for forming the ink supply rod while being adhered. It was gone. Moreover, the crack of the board | substrate by handling was also eliminated.

  In addition, it can be thermocompression-bonded by using polyetheramide of thermoplastic resin as a material to reinforce the ink supply but adhere the plate on which the beam is provided, and is resistant to silicon anisotropic etchant. The above process is possible.

  Since the created ejection element is provided with a beam on the back surface of the substrate, there is no beam on the nozzle forming surface of the ink supply port, so the ejection characteristics (particularly frequency characteristics) are uniform, and printing performance problems are eliminated.

  Therefore, it was possible to provide a discharge element with small droplets having good printing performance and high printing speed.

  Hereinafter, specific examples will be described.

  FIG. 1 is a plan view of the head of the embodiment.

  2 to 8 are sectional views taken along line X1-Y1 of FIG.

  7 (a) and 8 (a) are X2-Y2 cross-sectional views of FIG.

First, a heat storage layer is formed on a silicon substrate 101, 25 μ square heaters 102 are arranged at 600 dpi, and a protective layer is formed thereon. (Figure 2)
Next, 20 μm of resist 103 as a mold material for forming the nozzle flow path is applied on the substrate and patterned. (Figure 3)
Next, a photosensitive epoxy 104 that forms nozzles and discharge nozzles is applied. (Fig. 4)
Then, the photosensitive epoxy is patterned using a photolithography method to form an 18 μΦ discharge roller 105. (Fig. 5)
Next, 2 μm of polyetheramide 106 is applied as a mask material for forming an ink supply surface on the back surface of the substrate, and the polyetheramide is patterned by dry etching using oxygen using a photoresist as a mask. Then, the photoresist is removed. (Fig. 6)
Next, a beam 107 and a supply rod 108 as shown in FIG. 7 are formed by anisotropic etching using TMAH using a thermally oxidized SiO2 film as a mask material with the same pattern on both sides on a (100) oriented silicon substrate. The reinforcing plate 109 thus formed was formed and bonded to the nozzle-attached substrate by thermocompression bonding at 100 ° C. using the polyetherimide as an adhesive.

  7A is a cross-sectional view of the beam portion of the reinforcing plate, and FIG. 7B is a cross-sectional view of the reinforcing plate other than the beam.

  Next, the substrate with the reinforcing plate is placed in a tank in which TMAH is kept at 80 ° C., and an ink supply block 1110 having a shape as shown in FIG. 8 is formed by anisotropic etching.

  Since the reinforcing plate is formed by anisotropic etching with TMAH, the shape hardly changes.

  Moreover, since polyetherimide is strong against strong alkali, the reinforcing plate was not dropped during the anisotropic etching.

  It is possible to increase the thermocompression bonding temperature of the reinforcing plate to 200 ° C. However, the mold resist on the substrate is not heat resistant. Further, a polyetherimide coating pattern and a reinforcing plate thermocompression bonding may be performed. That is, FIG. 6 and FIG. 7 are performed between FIG. 2 and FIG.

Finally, the resist that has become the mold material is removed using a stripping solution to complete a substrate with a nozzle. (Figure 8)
The discharge element produced by the above process did not cause warping or cracking of the substrate even after the ink supply was formed by the reinforcing plate containing the beam. Since the beam is on the back surface of the substrate, the discharge performance, particularly the frequency performance, was not deteriorated and the printing performance was good. In the embodiment, the reinforcing substrate material is formed of silicon of (100) orientation, but silicon of (110) may be used. Further, silicon such as alumina which is resistant to the etching solution for forming the ink supply rod may be used.

  However, ordinary resins cannot be used because of problems such as warpage after thermocompression bonding due to the difference in thermal expansion coefficient from silicon.

Plan view of an embodiment of the present invention Process diagram of an embodiment of the present invention Process diagram of an embodiment of the present invention Process diagram of an embodiment of the present invention Process diagram of an embodiment of the present invention Process diagram of an embodiment of the present invention Process diagram of an embodiment of the present invention Process diagram of an embodiment of the present invention Illustration of conventional technology Illustration of conventional technology Illustration of conventional technology

Explanation of symbols

101 Silicon substrate
102 Heater
103 Mold material
104 Nozzle material
105 Discharge
106 Anisotropic etch mask
107 Reinforcement plate beam
108 Reinforcement plate ink supply
109 Reinforcing plate
110 Ink supply b

Claims (4)

In a method of manufacturing an ink jet recording head in which an ink flow path and an ink discharge roller are provided on a substrate provided with a heating resistor, and ink is discharged by utilizing foaming of ink due to heat generated by the heating resistor.
A step of applying and patterning a resin of a mold material for forming a nozzle flow path on a substrate having a heating resistor, a step of applying and patterning a resin forming an ink flow path and an ink discharge flow, and forming an ink supply flow For this purpose, the step of etching the substrate and the step of removing the resin of the mold material are bonded, and the plate provided with the beam for reinforcing the ink supply port is bonded before the step of etching the substrate for forming the ink supply rod. And a method of manufacturing an ink jet recording head characterized by flowing the subsequent steps of etching a substrate for forming an ink supply rod while being adhered.   2. The ink jet recording head manufacturing method according to claim 1, wherein the plate provided with the reinforcing beam is silicon.   2. The ink jet recording head manufacturing method according to claim 1, wherein the plate provided with the reinforcing beam is a ceramic material.   2. The method of manufacturing an ink jet recording head according to claim 1, wherein the material for adhering the plate provided with the reinforcing beam is polyetheramide.

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