JP2007007981A - Inkjet recording head and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an inkjet recording head that can improve the reliability by preventing a nozzle plate from being broken even when the thickness of the nozzle plate is reduced, and an inkjet recording head. <P>SOLUTION: A part 9' having a plurality of bend sections is formed on a connection portion between the nozzle plate 10 and an ink channel wall 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inkjet recording head that performs recording by ejecting a recording liquid (hereinafter referred to as “ink”) from an ink ejection port and attaching it to a recording material, and a method for manufacturing the inkjet recording head. Is.

  An ink jet recording head applied to an ink jet recording system (liquid jet recording system) generally has a fine ejection port, an ink channel (liquid channel) communicating with the ejection port, and a part of the ink channel. A plurality of sets of ink discharge energy generation units (liquid discharge energy generation units) are provided. In order to record a high-quality image using such an ink jet recording head, it is desirable that ink droplets of the same volume are always ejected from the plurality of ejection ports at the same ejection speed.

  In the ink jet recording head for realizing such ink droplet ejection, it is preferable that the distance between the electrothermal conversion element and the ejection port (hereinafter referred to as “OH distance”) is short. Since the OH distance almost determines the ejection volume of the ink droplet, it is necessary to set it accurately and with good reproducibility.

  As a method for manufacturing such an ink jet recording head, Patent Document 1 describes a method for manufacturing an ink jet recording head capable of forming an OH distance with a very high accuracy and with good reproducibility.

JP-A-6-286149

  However, even if the discharge port plate is thinly formed by the method described in Patent Document 1, the following problems may occur. That is, when the ink jet recording head is manufactured, stress is applied to the substrate due to the expansion and contraction of the member that supports the substrate on which the ink discharge pressure generating element is formed, and the ink flow path wall and the discharge port plate that form the ink flow path There is a possibility that the discharge port plate may be broken starting from the corner portion which is the coupling portion. Moreover, there is a possibility that the discharge port plate may be broken starting from a corner portion that is a connecting portion between the discharge port plate and the discharge port plate reinforcing portion.

  Furthermore, in order to prevent ink splattering at the time of distribution of the ink jet recording head and entry of dust and air into the nozzle, a protective tape is applied to the surface of the discharge port plate, and the nozzle is sealed and protected. During actual use of the recording head, there is a possibility that the discharge port plate may be broken due to the tensile stress when the protective tape is peeled off.

  An object of the present invention is to provide an ink jet recording head and a method for manufacturing the ink jet recording head, which can prevent breakage of the discharge port plate even when the discharge port plate is thinly formed and can further improve reliability. There is.

  In the ink jet recording head of the present invention, an ink channel is formed by an ink channel wall between a substrate having an ink ejection energy generating element and an ejection port plate on which an ink ejection port is formed. In an ink jet recording head capable of discharging ink in the ink flow path from the discharge port by using discharge energy generated by the generating element, at a joint portion between the end portion of the ink flow channel wall and the discharge port plate A plurality of bent portions are formed.

  In the ink jet recording head of the present invention, an ink channel is formed by an ink channel wall between a substrate including an ink ejection energy generating element and an ejection port plate on which an ink ejection port is formed. In an inkjet recording head capable of discharging ink in the ink flow path from the discharge port using discharge energy generated by a discharge energy generating element, the inner surface of the discharge port plate protrudes in a direction facing the substrate. The discharge port plate reinforcing portion is provided, and a plurality of bent portions are formed at a joint portion between the discharge port plate and the discharge port plate reinforcing portion.

  The ink jet recording head manufacturing method of the present invention includes an ink flow path wall between a substrate including an ink discharge energy generating element and a discharge port plate on which an ink discharge port is formed. Resin that can be dissolved on the inner surface of the substrate in a method of manufacturing an ink jet recording head that is formed and can eject ink in the ink flow path from the ejection port using ejection energy generated by an ejection energy generating element. Forming an ink flow path pattern portion having the shape of the ink flow path, and covering the ink flow path pattern portion with a coating resin for forming the ejection port plate and the ink flow path wall. And elution removal of the soluble resin that forms the ink flow path pattern portion, and the ink flow path pattern portion Forming a plurality of bent portions at a portion of the ink flow path pattern portion corresponding to a joint portion between the end portion of the ink flow channel wall and the discharge port plate, and coating the coating resin. The plurality of bent portions formed in the ink flow path pattern portion are transferred to a portion of the coating resin corresponding to a joint portion between the end portion of the ink flow channel wall and the discharge port plate. To do.

  According to the present invention, a plurality of bent portions are formed in the coupling portion between the ejection port plate and the ink flow path wall or the coupling portion between the ejection port plate and the ejection port plate reinforcing portion. In addition, when stress due to expansion / contraction during manufacture of the ink jet recording head or tensile stress during peeling of the protective tape is applied, these stresses can be dispersed. As a result, it is possible to improve the reliability of the ink jet recording head by increasing the strength of the connecting portion and preventing the discharge port plate from being broken.

  In addition, since the number of steps is hardly increased as compared with the conventional method for manufacturing an ink jet recording head, a highly reliable ink jet recording head can be manufactured without increasing the cost.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic perspective view of a substrate 1 of an ink jet recording head according to the first embodiment of the present invention, and FIG. 2 is a schematic plan view of the ink jet recording head according to the first embodiment of the present invention when completed.

  As shown in FIG. 3, when the ink jet recording head is completed, heaters (electrothermal conversion elements) 2 are arranged on both sides of the ink supply port 3 formed on the substrate 1. The ink channel wall 8 for forming the ink channel 7 and the ejection port plate 10 for forming the ejection port 6 for ejecting ink are formed of the same member. Each ink flow path 7 is formed so that each heater 2 is positioned independently, and each ejection port 6 is provided at a position facing each heater 2. The substrate 1 made of silicon, glass, ceramic, or the like functions as a part of the liquid flow path constituting member, and the ink flow path wall 8 and the discharge port plate 10 which are material layers that form the ink flow path and the discharge port. Functions as a support. The board | substrate 1 should just have such a function, and the shape and material are not specifically limited. A desired number of heaters 2 are arranged on the substrate 1. When the ink in the ink flow path 7 is heated by the heater 2, bubbles are generated in the ink, and the ink is discharged from the discharge port 6 by the foaming energy.

  FIGS. 3A to 3F are cross-sectional views taken along the line III-III in FIGS. 1 and 2 in each manufacturing stage of the recording head of FIG. 2, that is, III- passing through the center positions of the heater 2 and the discharge port 6. FIGS. It is III sectional drawing. 4A to 4F are cross-sectional views taken along the line IV-IV in FIGS. 1 and 2 in each manufacturing stage of the recording head in FIG. 2, that is, IV-IV passing through the position of the ink flow path wall 8. It is sectional drawing.

  In manufacturing the recording head, first, as shown in FIGS. 3A and 4A, a soluble resin 4 is coated on the substrate 1 including the heater 2. Examples of the coating method include spin coating and roll coating, and a dry film may be laminated. Examples of the soluble resin 4 include a positive resist ODUR manufactured by Tokyo Ohka Kogyo Co., Ltd.

  FIGS. 3B and 4B show a process of exposing through the photomask 100 shown in FIG. 5 in order to pattern the dissolvable resin 4 into the shape of the ink flow path (ink flow path pattern portion). Indicates. As a result, the resin 4 is subjected to a subsequent development process, as shown in FIGS. 3C and 4C, the portions 4A corresponding to the respective ink flow paths 7, and the common liquid chamber positioned therebetween. 12 (see FIG. 2) is formed. In the photomask 100 of FIG. 5, 101 is a part corresponding to the ink flow path wall 8, 102 is a part corresponding to the ink flow path 7, 103 is a part corresponding to the common liquid chamber 12, and III in FIG. FIG. 3B is a cross-sectional view taken along line -III, and FIG. 4B is a cross-sectional view taken along line IV-IV in FIG.

  In the photomask 100, a predetermined pattern that changes the degree of exposure stepwise is provided at the tip 101 A of the portion 101 corresponding to the ink flow path wall 8, that is, the portion corresponding to the tip 8 A of the ink flow path wall 8. Is formed. In the pattern, the exposure amount is reduced stepwise from the tip 101A toward the portion 103 corresponding to the common liquid chamber 12. For example, it is a pattern in which the area of the light transmitting portion becomes finer step by step to the limit resolution of the resin (positive resist) 4 as it goes from the tip 101A to the portion 103. Thus, by exposure through the pattern, a portion 9 having a plurality of (including infinite) bent portions is formed at the corner between the upper surface 4B-1 and the side surface 4B-2 in the portion 4B of the resin 4 after development. It is formed.

  The shape of the portion 9 is an arc shape as shown in FIG. 6A when it has an infinite bent portion. The part 9 can have a stepped shape as shown in FIGS. 6B and 6C according to the number (a plurality) of the bent portions. Such a shape of the part 9 can be set according to the pattern of the tip portion 101A of the photomask 100 described above.

  FIG. 3D and FIG. 4D show a process of coating the coating resin layer 5 to be the ink flow path wall 8 and the discharge port plate 10. The coating resin layer 5 is preferably photosensitive because the ink discharge ports 6 can be easily and accurately formed by photolithography. As the material, a cationic polymerization cured product of an epoxy resin has excellent strength, adhesion, and ink resistance. As a method for coating the coating resin layer 5, there are spin coating, roll coating, and the like as in the case of the dissolvable resin 4.

  FIG. 3E and FIG. 4E show a process of exposing light through the photomask 200 in order to form the discharge ports 6 in the coating resin layer 5. Since the coating resin layer 5 is a negative photosensitive resin, the portion facing the black portion 201 in the photomask 200 in FIG. 3E is not exposed. That portion is removed in the subsequent development step shown in FIGS. 3 (f) and 4 (f), whereby the discharge port 6 is formed.

  3 (f) and 4 (f), the dissolvable resin 4 is dissolved and removed with an alkaline solution or a solvent, and an ink supply port 3 for supplying ink is formed from the back of the substrate 1. A process is shown. In forming the supply port 3, any method can be used as long as a hole can be formed in the substrate 1. For example, there are methods such as blasting and etching, and the supply port 3 may be formed before the step of forming the discharge port 6. Of course, the ink supply port 3 may be provided at the edge portion of the substrate 1 or the like.

  With the above manufacturing method, the ink flow path wall 8 and the discharge port plate portion 10 can be formed of the same member. As described above, the ink flow path wall 8 is a wall for forming the ink flow path 7 independently with respect to the heaters 2 arranged on both sides of the ink supply port 3 in the substrate 1, and the discharge port. The plate 10 is a plate for forming the discharge ports 6 at positions facing the individual heaters 2.

  As shown in FIGS. 6A, 6 </ b> B, and 6 </ b> C, the resin 4 described above is provided at a joint portion between the discharge port plate 10 and the tip 8 </ b> A on the ink supply port 3 side of the ink flow path wall 8. A portion 9 ′ having a shape corresponding to the portion 9 is transferred. That is, a plurality of (including infinite) bent portions having a shape obtained by inverting the plurality of bent portions in the portion 9 of the resin 5 are formed in the portion 9 ′. A portion where such a portion 9 ′ is located, that is, a connecting portion between the tip 8 A of the ink flow path wall 8 and the discharge port plate 10 is a portion that is easily damaged during manufacture of the ink jet recording head. That is, when an inkjet recording head is manufactured, when a member (not shown) that supports and fixes the substrate 1 expands and contracts and stress is applied to the substrate 1, the stress is most easily concentrated on the discharge port plate 10.

  By forming the portion 9 'having a plurality of bent portions in such a fragile joint portion, the stress applied to the joint portion can be dispersed and the strength can be increased. As a result, destruction of the discharge port plate 10 can be prevented, the reliability of the ink jet recording head can be improved, and high-quality photographic image recording by discharging small droplets of ink can be realized.

  The shape of the portion 9 ′ having a plurality of bent portions is desirably an arc shape having an infinite bent portion as shown in FIG. However, the portion 9 ′ may have a shape in which two or more bent portions are formed stepwise as shown in FIGS. 6 (b) and 6 (c). Further, in the joint portion between the tip 8A of the ink flow path wall 8 and the ejection port plate 10, except for the portion where the portion 9 'is located, the corner having one bent portion is considered in consideration of the influence on the ink ejection. (See FIG. 3F).

(Second Embodiment)
7A, 7B, and 7C are cross-sectional views of the recording head in the manufacturing stage according to the second embodiment of the present invention.

  In the present embodiment, a convex discharge port plate reinforcing portion 11 is formed at a position facing the ink supply port 3 of the discharge port plate 10. The joint portion between the discharge port plate reinforcing portion 11 and the discharge port plate 10 includes a plurality of (including infinite) bent portions, like the joint portion between the tip 8A of the ink flow path wall 8 and the discharge port plate 10. A site 9 ′ having is formed.

  FIG. 7A shows a process of exposing through the photomask 110 in order to pattern the dissolvable resin 4 into the shape of the ink flow path 7 and the common liquid chamber 12. In the photomask 110, 112 is a portion corresponding to the flow path wall 8, 114 is a portion corresponding to the discharge port plate reinforcing portion 11, and 113 is a portion corresponding to the common liquid chamber 12. Reference numeral 111 denotes a portion corresponding to the boundary between the portion 112 and the portion 113, and the boundary between the portion 114 and the portion 113, and the exposure amount is stepwise like the tip portion 101A in the photomask 100 of the above-described embodiment. A predetermined pattern to be changed to is formed. The pattern is, for example, a pattern in which the area of the light transmission portion becomes finer step by step down to the limit resolution of the resin (positive resist) 4 as it goes from the portion 112 to the portion 113 and from the portion 114 to the portion 113. .

  By performing development after exposure using such a photomask 110, a plurality of portions are formed at the corners of the portion 4B of the resin 4 (positive resist) corresponding to the common liquid chamber 12, as shown in FIG. 7B. A portion 9 having a bent portion is formed. Thereafter, through the same steps as in FIG. 3 and FIG. 4, as shown in FIG. A portion 9 ′ having a plurality of (including infinite) bent portions is formed in the portion and the joint portion between the tip 8 </ b> A of the ink flow path wall 8 and the discharge port plate 10.

  In the ink jet recording head provided with the discharge port plate reinforcing portion 11, the connecting portion between the discharge port plate reinforcing portion 11 and the discharge port plate 10 is a connecting portion between the tip 8 </ b> A of the ink flow path wall 8 and the discharge port plate 10. As with, stress tends to concentrate and break easily. However, by forming a portion 9 ′ having a plurality of bent portions as in the present embodiment, the discharge port plate reinforcing portion is similar to the connection portion between the tip 8 A of the ink flow path wall 8 and the discharge port plate 10. The strength of the connecting portion between the discharge port plate 10 and the discharge port plate 10 can be increased, and the discharge port plate 10 can be prevented from being broken.

(Third embodiment)
8 and 9 are explanatory diagrams of an ink jet recording head 300 according to the third embodiment of the present invention.

  The ink jet recording head 300 is a protective tape 400 that can be peeled off from the surface of the discharge port plate 10 for the purpose of preventing ink scattering during distribution and preventing dust and air from entering the nozzles (including the discharge ports). Is pasted. The protective tape 400 seals the nozzle and protects it. In the recording head 300 provided with such a protective tape 400, when the protective tape 400 is peeled off during actual use, the ejection port plate 10 may be broken by the tensile stress. The tensile stress is caused by the connecting portion between the tip 8A of the ink flow path wall 8 and the discharge port plate 10 located on the downstream side in the peeling direction (X) of the protective tape 400, that is, the ink flow path located on the left side in FIG. It concentrates most on the joint between the tip 8A of the wall 8 and the discharge port plate 10.

  Therefore, in the present embodiment, as shown in FIG. 9, the connecting portion between the tip 8 </ b> A of the ink flow path wall 8 positioned on the left side of the ink supply port 3 in FIG. 9 and the discharge port plate 10, that is, the protective tape 400. A portion 9 ′ having a plurality of (including infinite) bent portions as described above is formed in the portion where the tensile stress at the time of peeling is most concentrated. Thereby, in the part where the tensile stress is most concentrated, the tensile stress applied to the part can be dispersed to increase the strength.

  In this manner, in the recording head 300 in which the surface of the discharge port plate 10 is protected by the protective tape 400 by forming the portions 9 ′ having a plurality of bent portions, the discharge port plate due to the tensile stress when the protective tape 400 is peeled off. 10 breakage can be prevented. Thereby, a highly reliable inkjet recording head can be provided.

  Note that the portion 9 'having a plurality of bent portions is not only the portion where the tip 8A of the ink flow path wall 8 located on the left side of the ink supply port 3 in FIG. In this case, it is desirable to form the ink flow path wall 8 on the right side of the ink supply port 3 at the connecting portion between the tip 8A of the ink flow path wall 8 and the discharge port plate 10.

(Other embodiments)
As an ink ejection energy generating element, various elements such as a piezoelectric element can be used in addition to the electrothermal conversion element (heater) as described above. In short, any device that generates energy for discharging ink may be used.

  Further, the ink jet recording head of the present invention is used in a so-called serial scan type ink jet recording apparatus, or is formed so as to extend over the entire recording area of the recording medium, so-called full line type. It can be used for an ink jet recording apparatus.

  Further, the shape of the portion 9 ′ having a plurality of bent portions is not limited to the above-described example but is arbitrary, and a plurality of bent portions for dispersing stress may be formed.

FIG. 2 is a schematic perspective view of a substrate provided in the ink jet recording head according to the first embodiment of the present invention. FIG. 2 is a schematic view of the ink jet recording head according to the first embodiment of the present invention as viewed from the direction of the discharge port. FIGS. 3A to 3F are cross-sectional views taken along the line III-III in FIGS. 1 and 2 in order to explain the manufacturing process of the ink jet recording head in FIG. FIGS. 4A to 4F are cross-sectional views taken along line IV-IV in FIGS. 1 and 2 in order to explain the manufacturing process of the ink jet recording head in FIG. It is a top view of the photomask used in the patterning process of FIG.3 (b). (A) to (c) are cross-sectional views for explaining different configuration examples of the connecting portion between the ink flow path wall and the discharge port plate in the ink jet recording head of FIG. (A) to (c) are diagrams for explaining a manufacturing process of the ink jet recording head according to the second embodiment of the present invention. It is a perspective view of the inkjet recording head in the 3rd Embodiment of this invention. It is explanatory drawing of the state which peels a protective tape from the inkjet recording head of FIG.

Explanation of symbols

1 Substrate 2 Electrothermal conversion element (heater)
DESCRIPTION OF SYMBOLS 3 Ink supply port 4 Dissolvable resin layer 5 Covering resin layer 6 Discharge port 7 Ink flow path 8 Ink flow path wall 9 The part which has a some bending part 9 'The part which has a some bending part 10 The discharge port plate 11 The discharge port Plate reinforcement part 100,200 Photomask 300 Inkjet recording head 400 Protective tape

Claims (10)

An ink channel is formed by an ink channel wall between a substrate having an ink ejection energy generating element and an ejection port plate on which an ink ejection port is formed, and the ejection energy generated by the ejection energy generating element is reduced. In an inkjet recording head capable of ejecting ink in the ink flow path from the ejection port,
An ink jet recording head, wherein a plurality of bent portions are formed at a joint portion between an end portion of the ink flow path wall and the discharge port plate. The discharge energy generating element, the discharge port, and the ink flow path are formed in a plurality of sets,
An ink supply port for supplying ink to the plurality of ink flow paths;
The joint portion close to the ink supply port among the joint portions between the end portion of the ink flow path wall and the ejection port plate is formed with more bent portions than the other joint portions. Item 10. The ink jet recording head according to Item 1.   The inkjet recording head according to claim 1, wherein the plurality of bent portions have an arc shape. The surface of the discharge port plate can be attached with a peelable protective tape,
The plurality of bent portions are formed at a joint portion between an end portion of the ink flow channel wall and the discharge port plate located on the downstream side in the peeling direction of the protective tape. Any one of the inkjet recording heads. An ink channel is formed by an ink channel wall between a substrate having an ink ejection energy generating element and an ejection port plate on which an ink ejection port is formed, and the ejection energy generated by the ejection energy generating element is reduced. In an inkjet recording head capable of ejecting ink in the ink flow path from the ejection port,
On the inner surface of the discharge port plate, a discharge port plate reinforcing portion that protrudes in a direction facing the substrate is provided,
An inkjet recording head, wherein a plurality of bent portions are formed at a joint portion between the discharge port plate and the discharge port plate reinforcing portion.   6. The ink jet recording head according to claim 1, wherein the discharge port plate and the ink flow path wall are integrally formed of a resin material. An ink channel is formed by an ink channel wall between a substrate having an ink ejection energy generating element and an ejection port plate on which an ink ejection port is formed, and the ejection energy generated by the ejection energy generating element is reduced. In the manufacturing method of an ink jet recording head capable of discharging the ink in the ink flow path from the discharge port,
Forming an ink flow path pattern portion in the shape of the ink flow path with a soluble resin on the inner surface of the substrate;
Coating a coating resin for forming the ejection port plate and the ink flow path wall on the ink flow path pattern portion;
Elution and removal of the soluble resin that forms the ink flow path pattern portion;
Including
In the step of forming the ink flow path pattern portion, a plurality of bent portions are formed in a portion of the ink flow path pattern portion corresponding to a joint portion between the end portion of the ink flow path wall and the discharge port plate;
In the step of coating the coating resin, the plurality of bent portions formed in the ink flow path pattern portion at a portion of the coating resin corresponding to a joint portion between the end portion of the ink flow channel wall and the discharge port plate A method for producing an ink jet recording head, comprising: transferring an ink. An ink channel is formed by an ink channel wall between a substrate having an ink ejection energy generating element and an ejection port plate on which an ink ejection port is formed, and the ejection energy generated by the ejection energy generating element is reduced. In the manufacturing method of an ink jet recording head capable of discharging the ink in the ink flow path from the discharge port,
Forming an ink flow path pattern portion in the shape of the ink flow path with a soluble resin on the inner surface of the substrate;
Coating a coating resin for forming the ejection port plate and the ink channel wall on the ink channel pattern part;
Elution and removal of the soluble resin that forms the ink flow path pattern portion;
Including
The ink flow path pattern portion includes a portion corresponding to a discharge port plate reinforcing portion protruding from an inner surface of the discharge port plate toward the substrate,
In the step of forming the ink flow path pattern portion, a plurality of bent portions are formed in a portion of the ink flow path pattern portion corresponding to a joint portion between the discharge port plate and the discharge port plate reinforcing portion,
In the step of coating the coating resin, the plurality of bent portions formed in the ink flow path pattern portion are transferred to a portion of the coating resin corresponding to a joint portion between the discharge port plate and the discharge port plate reinforcing portion. An ink jet recording head manufacturing method, comprising: Using a positive photosensitive resin as the soluble resin,
The ink jet pattern according to claim 7 or 8, wherein the step of forming the ink flow path pattern portion patterns the ink flow path pattern portion and the plurality of bent portions by exposing through a photomask. A manufacturing method of a recording head. 10. The method of manufacturing an ink jet recording head according to claim 9, wherein the photomask includes a portion that changes an exposure amount in a stepwise manner in a portion corresponding to the plurality of bent portions.

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