JP2007261169A - Liquid jet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit peeling of a coating resin layer (CR material) opening prepared in the perimeter of an ink jet port in a side shooter type liquid jet head. <P>SOLUTION: The liquid jet head comprises an ink jet port 104 formed in a coating resin layer 102 for forming an orifice plate at the ink jet port 104 and an opening 105 almost parallel to an ink jet port train. The birth of peeling by a stress concentration is inhibited. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head for generating ink droplets used in an ink jet recording system.

  The ink jet recording system is extremely small in noise generation during recording, can be recorded at high speed, can be fixed on so-called plain paper, and can be recorded without special processing. In that respect, it has been spreading rapidly in recent years.

A liquid ejecting head in which ink droplets are ejected in a vertical direction with respect to a substrate on which an ink ejection energy generating element is formed is referred to as a “side shooter type recording head”. The present invention relates to a structure of a shooter type liquid jet head. The liquid ejecting heads described in JP-A-4-10940, JP-A-4-10941, and JP-A-4-10942 disclose that the bubbles generated by heating the heating resistor are communicated with the outside air. Ink droplets are ejected. In these liquid ejecting heads, it is difficult to reduce the distance between the ink ejection energy generating element and the orifice, which has been difficult with the conventional side shooter type manufacturing method (for example, Japanese Patent Application Laid-Open No. 62-234941). Droplet recording can be easily achieved, and it is possible to meet the recent demand for high-definition recording.

  In recent years, there has been an increasing demand for improvement in printer output speed. This is related to the fact that the processing speed of the computer is improved and that the ink droplets are made minute in order to output a higher-definition image, so that a higher ink droplet density is required. In a large format printer or a printer connected to a network, the requirement is even more remarkable. As a method for improving the output speed of the printer, it is achieved by improving the number of ink droplets generated per time, that is, improving the ink discharge frequency and increasing the number of ink discharge ports. Usually, by doing both of these, higher-speed output is possible. Increasing the number of ink ejection ports means increasing the number of nozzles, leading to an increase in the length of the liquid ejecting head.

  The liquid jet head of the above-described invention can be manufactured by, for example, a method shown in Japanese Patent Laid-Open No. 11-138817 published by the present applicant. In the above-described invention, in addition to the conventional manufacturing method, a method for forming a base pattern on the outer periphery of the ink flow path pattern with a dissolvable resin layer is disclosed in order to maintain the film thickness uniformity of the orifice plate. Yes. In this case, since the thermal deformation temperature of the resin serving as the base is 110 ° C., the orifice plate portion may be deformed or damaged by heating exceeding this temperature during the curing process after the base formation. Therefore, an opening is formed on the outer periphery of the ink flow path in order to remove the base pattern.

  This manufacturing method will be briefly described with reference to FIGS. 4 (a) to 4 (d) and FIGS. 5 (a) to 5 (d). As shown in FIG. 4 and FIG. 5A, it can be dissolved on substrates 401 and 501 on which a desired number of ink discharge energy generating elements 402 and 502 such as heating resistors (electrothermal conversion elements) are arranged. Patterns 403 and 503 serving as ink flow paths are formed by the resin layer. In FIG. 5, a pattern 503 ′ serving as a base for an opening formed later is formed. The dissolvable resin layer may be formed in a pattern by, for example, exposure / development with, for example, ultraviolet rays or Deep-UV light after application by dry film lamination, resist spin coating, or the like. As a specific example, polymethyl isopropenyl ketone (ODUR-1010 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied by spin coating, dried, and then exposed and developed with Deep-UV light to form a pattern. Next, as shown in FIG. 4 and FIG. 5B, coating resin layers 404 and 504 are formed on the soluble resin layer by spin coating or the like. In FIG. 5, the covering resin layer 504 is formed with a base portion 503 ′ made of a soluble resin layer, whereby the upper surface of the ink flow path portion 503 can be formed more flat. Further, ink discharge ports 405 and 505 are formed in this coating resin layer (FIG. 4 and FIG. 5C).

  The openings 406 and 506 around the ink flow path are formed at the same time or at different times when the ink discharge ports are formed. When the base portion is formed of a soluble resin layer as shown in FIG. 5, the opening is formed at the same position as the base portion.

  The ink discharge port and the opening can be formed by exposure with, for example, ultraviolet rays or deep-UV light. More specifically, it is formed by applying a negative type dyst by spin coating, drying, and pattern exposure and development with ultraviolet rays.

Next, ink supply ports 407 and 507 are formed on the substrates 401 and 501. The ink supply port is formed by chemically etching the substrate. For example, a Si substrate is used as the substrate, and the substrate is formed by anisotropic etching with a strong alkali solution such as KOH, NaOH, TMAH (FIG. 4, 5 (d)). As a more specific example, a thermal oxide film formed on a Si substrate having a crystal orientation of <110> is patterned,
The Si substrate is etched with a TMAH 22% solution heated to 80 ° C. for 10 hours to form an ink supply port. The ink supply port may be formed before forming the ink flow path pattern and the base portion pattern (FIGS. 4 and 5 (a)) or forming the ink discharge port (FIGS. 4 and 5 (c)). Is possible.

  Subsequently, as shown in FIGS. 4 and 5 (d), the dissolvable resin layers 403, 503, and 503 ′ are eluted from the ink discharge port, the ink supply port, and the opening, so that the ink flow path and the foaming chamber are obtained. Is formed. The method for removing the dissolvable resin layers 403, 503, and 503 ′ may be performed after the entire surface exposure with Deep-UV light, followed by dissolution and drying. If necessary, ultrasonic treatment may be performed at the time of dissolution. It can be done more reliably and in a short time.

  The substrate on which the nozzle portion has been manufactured through the above steps is separated and cut into chips using a dicing saw or the like, and after electrical bonding (not shown) for driving the ink discharge pressure generating element, ink supply is performed. For example, a member such as a chip tank is connected to complete the ink jet head.

  The reason for providing the opening around the ink supply port is to avoid the following.

  For example, if everything except the ink discharge port and the electrical connection is covered with the coating resin, the substrate is deformed due to the hardening of the coating resin layer or the stress caused by the temperature change. To avoid concentrating on the edge, that is, the wall of the ink flow path and peeling off from the substrate. (Especially, if the soluble resin layer that is the foundation is left, the deformation due to heat becomes severe.) Also, the coating resin layer is left only around the ink discharge port, and all the outer coating resin layers are lost. Because the substrate surface is exposed, there is a possibility that the substrate surface may be damaged and defective when mounting the liquid jet head or mounting it on a printer. In order to avoid these problems, an opening is provided around the ink discharge port to remove the base resin layer that can be dissolved, to reduce the stress applied to the ink flow path wall of the coating resin layer as much as possible, and to prevent the substrate surface from being scratched. It is compatible to protect.

  FIG. 6 is a schematic view of a conventional liquid jet head as viewed from above. Reference numeral 601 denotes a substrate, 602 denotes a coating resin layer, 604 denotes an ink discharge port array, 605 denotes an opening, and 603 denotes an ink supply port. In the liquid ejecting head shown here, the ink discharge port arrays are arranged one by one on both sides of the ink supply port.

In the corner portions 606 and 607 of the independent coating resin layer formed by the openings formed around the ink flow path of the liquid jet head manufactured as described above, the coating resin layer is increased along with the increase in the length of the liquid jet head. Various acceleration tests revealed that there is a possibility of peeling. This is because the stress of the independent coating resin layer of the liquid jet head concentrates on the corner portion, and peeling occurs from the corner portion as a starting point. It was also found that the thicker the coating resin layer, the greater the stress and the easier it is to generate.
Japanese Patent Laid-Open No. 4-10940 JP-A-4-10941 JP-A-4-10942 JP 62-234941 A JP 11-138817 A

  SUMMARY An advantage of some aspects of the invention is that it provides a side shooter type liquid jet head having high reliability.

  A liquid ejecting head in which ink droplets are ejected from a plurality of ink ejection port arrays in a direction substantially perpendicular to a substrate surface having a plurality of heating elements, wherein the ink ejection ports and the ink are formed on a coating resin layer forming an orifice plate. In the liquid jet head, an opening that is substantially parallel to the ejection port array is provided.

  Electrical connections were made to the heads of Examples 1 to 3, ink tanks were connected, and ink jet heads were created. When these were subjected to a temperature and humidity cycle test, peeling of the opening of the coating resin layer did not occur at all, or even if it occurred, it was a level that would not cause a substantial problem. There was no change in printing before and after the test, and good printing was maintained. The temperature and humidity cycle test was performed as follows. While maintaining a relative humidity of 95%, the temperature was increased from 25 ° C. to 65 ° C. at a constant rate over 2 hours and 30 minutes, held at 65 ° C. for 3 hours, and then decreased to 25 ° C. over 2 hours and 30 minutes at a constant rate. Again, the temperature was raised from 25 ° C. to 65 ° C. at a constant rate over 2 hours and 30 minutes, held at 65 ° C. for 3 hours, lowered to 25 ° C. at a constant rate over 2 hours and 30 minutes, and at 25 ° C. for 1 hour and 30 minutes. After holding, holding for 3 hours 30 minutes at a relative humidity of 0% temperature −10 ° C. and then holding at 25 ° C. and 95% for 3 hours was taken as one cycle, and this was repeated for 10 cycles.

  As a comparison, when the temperature and humidity cycle test of the conventional liquid jet head shown in FIG. 6 was performed in the same manner, the coating resin layer peeled off from the edge of the opening and reached the nozzle flow path. Only a thin one was obtained.

  The present invention is also effective as a full-line type liquid ejecting head capable of recording simultaneously over the entire width of the recording paper, and further to a color liquid ejecting head in which recording heads are integrated or combined.

  As described above, according to the present invention, the following effects can be obtained. In other words, it is possible to provide a liquid ejecting head that is highly reliable and can maintain stable ejection because the resin layer does not peel or does not cause a problem even if it occurs. Become.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Note that the above-described method can be applied to the method of manufacturing the liquid jet head for realizing the present invention, but the present invention is not limited by the manufacturing method.

  FIG. 1 shows one embodiment of the present invention. Reference numeral 101 denotes a substrate, 102 denotes a coating resin layer, 103 denotes an ink supply port formed from the back surface, 104 denotes a nozzle row, and 105 denotes an opening of the coating resin layer. Conventionally, with respect to the opening portion 105 of the coating resin layer provided so as to surround the periphery of the nozzle row, the opening portion perpendicular to the nozzle row is eliminated, and the opening portion is formed only in a portion substantially parallel to the nozzle row. It can be easily formed by changing the mask for patterning the opening of the coating resin layer. Compared with the prior art, the independent part of the coating resin layer is eliminated. That is, by eliminating the corner portion of the coating resin layer, stress concentration is prevented and peeling is difficult.

  FIG. 2 shows another embodiment of the present invention. While providing the opening part of the coating resin layer in parallel with the nozzle row, the shape of the edge part of the opening part was a so-called jagged shape provided with a plurality of peaks and valleys. It can be easily formed by changing the mask for patterning the opening of the coating resin layer. For example, as shown in FIG. 2 ′, the stress F (206) acting on the point X is decomposed into 207 and 208. Among these, at point X, the force P for peeling off the coating resin layer is Fsinθ. Here, since θ ≠ 90 °, sin θ <1. Therefore, P <F, and the stress acting on the edge is small. Therefore, it is assumed that it is difficult to peel off from the edge of the coating resin layer opening.

  FIG. 3 shows another embodiment of the present invention. While providing the opening part of the coating resin layer in parallel with the nozzle row, the width of the opening part was made into the staircase shape which spreads from the substrate surface toward the coating resin layer surface. The coating resin layer opening completed in Example 1 can be formed by half-cutting with a dicing saw. By reducing the thickness of the stress acting on the edge of the coating resin layer opening, the stress is reduced. By carrying out like this, it was supposed that it was hard to peel with respect to peeling from the edge of the coating resin layer opening.

FIG. 3 is a schematic diagram of a liquid jet head according to the present invention. FIG. 6 is a schematic diagram of a liquid jet head showing another embodiment of the invention. FIG. 6 is a schematic diagram of a liquid jet head showing another embodiment of the invention. It is a typical sectional view showing a manufacturing process of a conventional liquid jet head. It is a typical sectional view showing a manufacturing process of a conventional liquid jet head. It is a schematic diagram of a conventional liquid jet head.

Explanation of symbols

101, 201, 301, 401, 501, 601 Substrate 402, 502 Ink discharge energy generating element 403, 503 Dissolvable resin layer (ink flow path portion)
503 'Dissolvable resin layer (base part)
102, 202, 302, 404, 504, 602 Coating resin layer (orifice plate)
104, 204, 304, 405, 505, 604 Ink discharge port or ink discharge port array 105, 205, 305, 406, 506, 605 Opening 103, 203, 303, 407, 507, 603 Ink supply port 206 Stress 207 Opening Stress component acting in the tangential direction of the edge of the portion 208 Stress component acting perpendicular to the edge of the opening (force to peel off)
606, 607 Covering resin layer corner

Claims (3)

  A liquid ejecting head in which ink droplets are ejected from a plurality of ink ejection port arrays in a direction substantially perpendicular to a substrate surface having a plurality of heating elements, wherein the ink ejection ports and the ink are formed on a coating resin layer forming an orifice plate. A liquid ejecting head, wherein an opening that is substantially parallel to the ejection port array is provided.   The liquid ejecting head according to claim 1, wherein the shape of the edge of the opening substantially parallel to the ink ejection port array is a so-called jagged shape having a plurality of peaks and valleys.   The liquid ejecting head according to claim 1, wherein the shape of the edge of the opening that is substantially parallel to the ink discharge port array is a stepped shape in which the opening width increases from the substrate surface to the surface of the coating resin layer.

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