JP2006281715A - Liquid delivery head and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reinforce the adhesion of a delivery element substrate and the support and prevent an adhesive from flowing out. <P>SOLUTION: A nozzle layer 2 with a delivery port 4 and a passage 5 is formed on the delivery element substrate 1 with a heating resistor 3, and the rear face side of the delivery element substrate 1 is bonded to the support not shown in Fig. Pits 7 of a square pyramid shape for reserving the adhesive are formed and dispersed highly densely in the rear face side of the delivery element substrate 1. Thus, the adhesion is enhanced by the wedge effect and the adhesive is prevented from flowing out into an ink feeding port 6 of the delivery element substrate 1 and the communicating section of the support. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid discharge head mounted on a recording apparatus that performs recording by ejecting liquid to form flying droplets and a method for manufacturing the same.

  In addition, the present invention includes a printer, a copying machine, a facsimile having a communication system, and a printer unit that perform recording on a recording medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, and the like. The present invention can be applied to a device such as a word processor, or an industrial recording device combined with various processing devices.

  [Recording] in the present invention means not only giving an image having a meaning such as a character or a figure to a recording medium but also giving an image having no meaning such as a pattern.

  For example, as shown in FIG. 8, a conventional liquid ejection head includes a nozzle layer 102 having an ejection port 104 for ejecting ink and a channel 105 communicating with each ejection port 104, and a part of the channel 105. A discharge element substrate 101 having an ink supply port 106 for supplying ink to the heating resistor 103 and each flow path 105 that are configured and a discharge element; and a communication unit 109 that is in communication with the ink supply port 106. The support element 108 supports the discharge element substrate 101.

  FIG. 9 shows a manufacturing method of a liquid discharge head. A liquid discharge head using a heating resistor 103 as an discharge element is generally used as a semiconductor manufacturing technique. Manufactured by a method of forming a liquid discharge head. For example, using a Si substrate having a crystal orientation of <100> plane, a heating resistor 103 and a driving element (not shown) for driving the heating resistor 103 are formed by semiconductor manufacturing technology, and then the heating resistor 103 and external control A discharge element substrate 101 on which an electrical extraction electrode (not shown) with the device is formed is used.

First, as shown in FIG. 9A, a mask M used for anisotropic etching for forming the ink supply port 106 is formed as follows. A mask material is applied to the back surface of the ejection element substrate 101 with a desired film thickness. As the mask material, a resin that does not deteriorate with an anisotropic etching solution is used. A positive photoresist is applied onto the mask material, and the resist corresponding to the ink supply port 106 is removed through an exposure and development process. Then, after removing the mask material corresponding to the ink supply port 106 by dry etching, the resist is removed to form the mask M having the opening M ₁ . The mask M may be formed of a material that can be patterned by the mask material itself.

  As a method of forming the nozzle layer 102 of the liquid discharge head, a removable nozzle mold material R that becomes the flow path 105 is formed by a photolithography technique. As the nozzle mold material R, a positive photoresist is used and applied in a desired film thickness (this film thickness corresponds to the height of the flow path 105). Thereafter, the pattern of the flow path 105 is formed through exposure and development processes.

  Next, as shown in FIG. 9B, a nozzle layer 102 made of a cation-polymerized negative resist by photoreaction is applied by spin coating so as to cover the removable nozzle mold material R that becomes the flow path 105. . Then, the discharge port 104 and the like are formed in the nozzle layer 102 by a photolithography technique.

  Next, as shown in FIG. 9C, the oxide film 101a corresponding to the ink supply port 106 is removed by chemical dry etching, and then anisotropic etching is performed to form the ink supply port 106. I do. For example, etching is performed using a TMAH (tetramethylammonium hydroxide) 22% aqueous solution heated to 83 ° C. as an anisotropic etching solution. After the anisotropic etching is completed, the mask M is removed.

  As shown in FIG. 9D, exposure is performed from the surface of the nozzle layer 102, and the nozzle mold material R that becomes the flow path 105 is removed using a mold material removing liquid. Since a positive photoresist is used for the nozzle mold material R, the removal of the nozzle mold material R can be performed by using a general positive photoresist release agent. By passing through the above steps, the ejection element chip of the liquid ejection head is manufactured, and the back surface of the chip is bonded to the support 108 shown in FIG. 8B. That is, the adhesive 110 is applied to the support 108, the back surface of the discharge element substrate 101 is bonded, and electrical bonding (not shown) for driving the heating resistor 103 is performed to complete the liquid discharge head. .

  When the discharge element substrate and the support are bonded, if the adhesive force is not sufficient, peeling may occur during the discharge operation, resulting in a discharge failure. In particular, when a plurality of ink supply ports are formed in one ejection element substrate, a plurality of inks may be mixed up to the gap between the ejection element substrate and the support to cause a defect.

  In addition, due to variations in the amount of adhesive that bonds the ejection element substrate and the support, the adhesive may protrude to the ink supply port and the communication part of the support, and may further reach the flow path of the nozzle layer. As a result, the flow path shape may be deformed to adversely affect the discharge.

As a method for solving these problems, Patent Document 1 discloses that a groove is formed around the ink supply port on the back surface of the ejection element substrate, and a protrusion provided on the support plate is fitted to facilitate positioning. In addition, a configuration for controlling the application area of the adhesive is disclosed.
Japanese Patent Laid-Open No. 9-314841 JP 2002-326361 A

  However, in the configuration disclosed in Patent Document 1, the substrate size is reduced as the liquid discharge head is reduced, and the width between the supply ports is reduced as the number of colors is increased. The protrusion to be formed also needs to be thin. Therefore, a special process is required to integrally form a projection with high dimensional accuracy on a support made of ceramic or the like, and the support is expensive.

  In addition, in the configurations disclosed in Patent Documents 1 and 2, it is necessary to form a narrow groove width formed on the back side of the substrate, and when a necessary amount of adhesive is applied to bond the ejection element substrate and the support. In some cases, the adhesive that does not fit in the groove space protrudes to the ink supply port and the communication portion, making it difficult to control the coating area.

  The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and uses a low-cost support to control the adhesive application area of the ejection element substrate and the support and to improve the adhesive force. It is an object of the present invention to provide a liquid discharge head that can be made and a manufacturing method thereof.

  In order to achieve the above object, a liquid discharge head according to the present invention includes a discharge element substrate having a liquid supply port and a discharge element, a flow path forming layer having a discharge port and a flow path on the discharge element substrate, and the discharge element. A liquid discharge head that discharges liquid droplets from the discharge port, and is scattered at a predetermined density on the back surface of the discharge element substrate so as to face the support. Pit-shaped minute holes are formed.

  The method for manufacturing a liquid discharge head according to the present invention includes a step of forming a flow path forming layer having a discharge port and a flow path for discharging a liquid on a discharge element substrate having discharge elements, and anisotropic etching on the discharge element substrate. The step of forming a liquid supply port by the step, the step of forming pit-shaped micro holes scattered at a predetermined density on the discharge element substrate, and the discharge element substrate supported by the adhesive filled in the pit-shaped micro holes And a step of adhering to.

  By spraying pit-shaped minute holes that do not penetrate through the bonding part between the support and the discharge element substrate, the adhesive application area is controlled by flowing into the minute holes without flowing into the liquid supply port. Can do.

  Further, the cost of the support can be reduced by omitting the special process for forming the protrusion on the support.

  Furthermore, by forming the pit-shaped micro holes in a high-density and fine pattern, the wedge effect due to the inflow of adhesive into the pit-shaped micro holes is increased, and the adhesive strength between the discharge element substrate and the support is further improved. Can be made.

  As shown in FIG. 1, in a liquid discharge head including a discharge element substrate 1 made of a Si substrate or the like and a nozzle layer 2 that is a flow path forming layer provided on the discharge element substrate 1, the discharge element substrate 1 is The heating resistor 3 is a discharge element that generates a discharge pressure for discharging the liquid ink in a direction perpendicular to the substrate surface. The nozzle layer 2 includes a discharge port 4 and a flow path 5 formed on the discharge element substrate 1, and the flow path 5 is an ink supply port that is a liquid supply port formed in the discharge element substrate 1 by anisotropic etching. 6 communicates.

  As shown in FIG. 1B, high-density and minute pit-shaped portions 7 are dotted on the back surface of the discharge element substrate 1, and as shown in FIG. As a result, the bonding of the discharge element substrate 1 and the support 8 by the adhesive 10 is strengthened.

  The density of the pit shape portions may be uniform, or the pit shape portions may be arranged with a higher density as they approach the ink supply port.

  Each pit shape portion may be a quadrangular pyramid, a quadrangular frustum, or a minute hole having a combination thereof.

  The nozzle layer is formed by, for example, forming a discharge port and a flow path with photolithography using a nozzle material made of a negative resist, and removing an oxide film on the ink supply port forming portion on the back surface of the discharge element substrate, thereby making the anisotropic An ink supply port is formed by etching. The pit shape portion on the back surface of the discharge element substrate is also formed by anisotropic etching.

  The pit shape portion and the ink supply port may be simultaneously anisotropically etched.

As shown in FIG. 1, the heating resistor 3 and the like were formed on the discharge element substrate 1 by the same method as in the prior art using a Si substrate having a thickness of 0.625 mm. As shown in FIG. 2, a mask material M ₀ for anisotropic etching is applied onto the oxide film 1a on the back surface of the discharge element substrate 1 using a spinner, and then a positive photoresist is applied to the ink supply port. 6 and a mask having a transmission pattern corresponding to the pit forming portion 7, and a pattern was formed by development. Note that the pit shape portion 7 is formed only at the bonding portion between the ejection element substrate 1 and the support 8.

  By the anisotropic etching for forming the ink supply port 6, the ejection element substrate 1, which is a Si substrate, is etched with an inclination of 54.7 °. Therefore, a transmissive pattern of the mask is formed so that the pit shape portion 7 has a dimension that does not penetrate the ejection element substrate 1. In this example, the transmission pattern corresponding to the pit shape portion on the mask was formed with a 10 μm square.

Then, after removing the mask material M ₀ at portions corresponding to the ink supply port 6 and the pit forming portion 7 by dry etching, the resist was removed. Then, the nozzle layer 2 was formed according to the conventional manufacturing method. Next, the oxide film 1a corresponding to the ink supply port 6 and the like was removed by chemical dry etching, and anisotropic etching was performed to form the ink supply port 6 and the pit shape portion 7.

FIG. 2 shows the above anisotropic etching process in the pit shape portion 7. As shown in FIG. 2A, a mask material M ₀ is applied to the ejection element substrate 1, and as shown in FIG. 2B, the mask material M ₀ is etched to form a mask M having an opening M _1. , an oxide film 1a of the opening M ₁ is removed as shown in (c), (d), the by performing an anisotropic etching process, such as pit-shaped portion 7 is formed.

  Thereafter, the mask M and a nozzle mold material (not shown) were removed by a known method, thereby completing the ejection element chip of the liquid ejection head.

  The pit shape portion of this example has a quadrangular pyramid shape as shown in FIG. 1 and is formed with 240 μm square and 90 μm depth.

In this embodiment, as shown in FIG. 3, the density of the pit-shaped portions 7 is increased as the ink supply port 6 is approached. As shown in FIG. up to the step of applying the mask material M ₀ adopts the same process as in example 1.

Thereafter, a positive photoresist was applied, exposed using a mask having a transmission pattern at a site corresponding to the ink supply port 6, and pattern formation was performed by development. Thereafter, the mask material M ₀ corresponding to the ink supply port 6 was removed by chemical dry etching, and the oxide film 1a was also removed.

Next, the resist was exposed and developed using a mask having a transmission pattern at a site corresponding to the pit shape portion 7. The transmission pattern corresponding to the pit shape portion 7 was formed so that the density was higher as the ink supply port 6 was closer to the bonding portion between the ejection element substrate 1 and the support 8 shown in FIG. Thereafter, the mask material M ₀ corresponding to the pit shape portion 7 was removed by dry etching to form an opening M _1, and after removing the resist, the nozzle layer 2 was formed according to a conventional manufacturing method.

  Next, the oxide film 1a corresponding to the pit shape portion 7 is removed to such an extent that a thin layer remains by chemical dry etching, and then anisotropic etching is performed, whereby the ink supply port 6 and the pit shape portion 7 are removed. Formed simultaneously.

  A potassium hydroxide solution was used as an anisotropic etchant. Unlike TMAH, KOH can also remove oxide films. However, since the etching rate of the oxide film is slower than that of Si, the etching amount can be reduced in the pit shape portion where only a thin layer of the oxide film is left.

  Therefore, pit-shaped portions that are smaller than those in the first embodiment can be arranged with higher density.

FIG. 4 shows the anisotropic etching process in the pit shape portion 7. First, as shown in FIG. 4A, a mask material M ₀ is applied onto the ejection element substrate 1, and the mask material M ₀ is etched to form an opening M ₁ as shown in FIG. As shown in (c), the etching process is performed so that the oxide film 1a remains, and the anisotropic etching process is performed, whereby the pit shape portion 7 is formed as shown in (d).

  Thereafter, the mask M and a nozzle mold material (not shown) were removed by a known method, thereby completing the ejection element chip of the liquid ejection head.

  The pit shape portion of this example has a quadrangular pyramid shape as shown in FIG. 3, and is formed with a 100 μm square and a 70 μm depth.

  Using the element chip of Example 2, bonding to the support 8 was performed as shown in FIG. As the adhesive 10, an adhesive that was cured by heat or UV irradiation was used. First, the adhesive 10 is transferred to the surface of the support 8 so as to have a thickness of 15 μm. Next, the discharge element substrate 1 and the support 8 are aligned and bonded by pressure until a gap of 3 μm thickness is obtained. At this time, since the pit-shaped portion 7 is hardly formed on the outer peripheral portion of the chip back surface, the adhesive 10 protrudes to the outside of the chip. In this state, UV light is irradiated to the outer periphery of the chip, and the adhesive 10 protruding from the outer periphery of the chip is cured. Thereby, the ejection element substrate 1 and the support 8 are temporarily joined. Further, in the portion near the ink supply port 6 on the back surface of the ejection element substrate 1, excess adhesive 10 is guided into the pit-shaped portion 7, so that the ink supply port 6 and the support 8 protrude from the communication portion 9. Can be prevented. That is, by providing the pit shape portion 7, an effect equivalent to extending the distance from the adhesive application portion to the ink supply port 6 can be obtained.

  Thereafter, heating is performed in order to cure the adhesive 10 in a region not irradiated with UV, thereby completing the bonding between the discharge element substrate 1 and the support 8.

  In the liquid discharge head manufactured in this way, the adhesive 10 that joins the discharge element substrate 1 and the support 8 does not flow into the ink supply port 6 or the communication portion 9, and the discharge is caused by the shape change of the flow path 5. There was no defect. Further, it was confirmed that the adhesive strength was also improved as compared with that without the pit shape portion 7.

  Further, in this embodiment, the pit-shaped portions 7 are formed so as to be arranged in the same row in the longitudinal direction of the ink supply port 6, but in the case where they are arranged in a staggered manner in the longitudinal direction of the ink supply port 6. However, the effect on the induction of the adhesive 10 was great.

  In this embodiment, as shown in FIG. 6, a small-sized square pyramid-shaped pit-shaped portion 7 a is provided in the vicinity of the ink supply port 6, and a large-sized square pyramid trapezoidal shape is formed on the outer peripheral portion of the ejection element substrate 1. The pit shape portion 7b is provided at a substantially constant depth.

As shown in FIG. 7, the process up to the step of removing the oxide film 1a so as to correspond to the ink supply port 6 is the same as in the second embodiment. Next, the resist was exposed and developed using a mask having a transmission pattern at the portions corresponding to the pit shape portions 7a and 7b. The mask used for resist exposure was formed so that the pattern became smaller as the ink supply port 6 of the ejection element substrate 1 was closer. Thereafter, the mask material M ₀ was removed by dry etching so as to correspond to the pit shape portions 7a and 7b, and then the resist was removed.

FIG. 7 shows an anisotropic etching process in the pit shape portion 7b having a truncated pyramid shape. As shown in FIG. 7A, a mask material M ₀ is applied to the ejection element substrate 1, and as shown in FIG. 7B, the mask material M ₀ is dry-etched to form an opening M _2. As shown in c), an etching process is performed so that the oxide film 1a remains, and as shown in (d), an anisotropic etching process is performed on the discharge element substrate 1 to form the pit shape portion 7b. .

  Since the opening size of the mask M corresponding to the pit shape portion 7b is large, most of the etching time is spent in etching the oxide film 1a. Then, after the oxide film 1a is etched, the ejection element substrate 1 starts to be etched. For this reason, the etching time of the pit shape portion 7b is substantially very short, and the etching is finished before the etched shape becomes a quadrangular pyramid, resulting in a quadrangular pyramid shape.

  If the pit-shaped portion is formed in a quadrangular pyramid shape, the adhesive cannot be supplied to the pit tip, leaving bubbles, which may cause poor adhesion due to bubble expansion due to heat bonding. However, by adopting the quadrangular pyramid shape, these defects can be eliminated, and further, the adhesive force can be improved by the wedge effect.

1A and 1B show a main part of a liquid discharge head according to a first embodiment, in which FIG. 1A is a cross-sectional view thereof, and FIG. FIG. 3 is a process diagram showing a manufacturing process of Example 1. FIG. 2 shows a main part of a liquid discharge head according to a second embodiment, where (a) is a cross-sectional view thereof and (b) is a plan view showing a back surface of a chip. 6 is a process diagram showing a manufacturing process of Example 2. FIG. It is sectional drawing which shows the state which adhere | attached the element chip | tip of FIG. 3 on the support body. FIG. 7 shows a main part of a liquid discharge head according to Embodiment 3, wherein (a) is a cross-sectional view thereof, and (b) is a plan view showing a back surface of a chip. 10 is a process diagram showing a manufacturing process of Example 3. FIG. 1 shows a main part of a liquid discharge head according to a conventional example, in which (a) is an explanatory view for explaining an internal configuration of a discharge element substrate, and (b) is a sectional view. FIG. 9 is a process diagram illustrating a manufacturing process of the liquid ejection head in FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Discharge element board | substrate 2 Nozzle layer 3 Heating resistor 4 Discharge port 5 Flow path 6 Ink supply port 7, 7a, 7b Pit shape part 8 Support body 10 Adhesive

Claims (6)

A discharge element substrate having a liquid supply port and a discharge element; a flow path forming layer having a discharge port and a flow path on the discharge element substrate; and a support bonded to the back surface of the discharge element substrate. In the liquid ejection head that ejects droplets from the outlet,
A liquid discharge head, wherein pit-shaped micro holes scattered at a predetermined density are formed on the back surface of the discharge element substrate so as to face the support.   The liquid discharge head according to claim 1, wherein the pit-shaped minute holes are arranged with a higher density as they approach the liquid supply port.   3. The liquid discharge head according to claim 1, wherein the pit-shaped minute hole has a polygonal pyramid shape.   The liquid discharge head according to claim 1, wherein the pit-shaped minute hole has a polygonal frustum shape. Forming a flow path forming layer having a discharge port and a flow path for discharging a liquid on a discharge element substrate having a discharge element;
Forming a liquid supply port by anisotropic etching on the discharge element substrate;
Forming pit-shaped micro holes scattered at a predetermined density in the discharge element substrate;
And a step of adhering the ejection element substrate to the support with an adhesive filled in a pit-shaped minute hole.   6. The method of manufacturing a liquid discharge head according to claim 5, wherein the pit-shaped minute hole and the liquid supply port are simultaneously formed by anisotropic etching.

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