JP2014240142A - Liquid discharge head, liquid discharge device, and manufacturing method of liquid discharge head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head which enables a flow velocity of a liquid to be increased in a passage from a supply port to a pressure chamber.SOLUTION: A recording head 3 includes a supply port 11 for supplying a liquid in a pressure chamber 22. A rough surface, which increases a flow velocity of a liquid circulating in a passage by its surface being roughly formed, is formed at a position facing the passage 12 for circulating the liquid supplied from the supply port 11 to the pressure chamber 22.

Description

  The present invention relates to a liquid discharge head for discharging a liquid, a liquid discharge apparatus using the liquid discharge head, and a method for manufacturing the liquid discharge head.

  As the liquid ejection apparatus, there is an ink jet recording apparatus that performs recording by ejecting liquid from a liquid ejection head onto a recording medium. As a liquid discharge head used in an ink jet recording apparatus, an energy generating element is provided in a liquid flow path, and the energy is applied to the liquid in the ink flow path by driving the energy generating element so that the liquid is discharged from the discharge port. There is a discharge type.

  An example of the liquid discharge head is disclosed in Patent Document 1. Patent Document 1 discloses a recording head as a liquid ejection head in which serrated irregularities are formed in a flow path between a supply port and a pressure chamber. By forming the recording head in this way, even if stress is applied to the flow path forming member, the stress is divided into a component force along the edge and a component force orthogonal to the edge. Peeling from the substrate can be suppressed.

JP 2003-80717 A

  However, in the recording head disclosed in Patent Document 1, serrated irregularities formed in the flow path are formed relatively large. Therefore, in the recording head disclosed in Patent Document 1, the contact angle of the liquid to the wall surface when the liquid flows through the flow path between the supply port and the pressure chamber is such that the surface at the position facing the flow path is smooth. It will not be smaller than there is. In addition, the meniscus does not receive a force in such a direction that the contact angle becomes small during refilling after the liquid is ejected by the recording head. Therefore, the moving speed of the meniscus at the time of refilling does not change, and the moving speed of the meniscus at the time of refilling may be insufficient.

  In a liquid ejection apparatus, normally, once a liquid is ejected, the next liquid cannot be ejected during the refill time until the liquid is supplied again to the flow path and filled. If this refill time becomes longer, the time until the next liquid discharge becomes possible becomes longer, and there is a possibility that the time required to record a predetermined recorded image becomes longer.

  In view of the above circumstances, an object of the present invention is to provide a liquid discharge head, a liquid discharge apparatus, and a method for manufacturing a liquid discharge head that can increase the flow rate of liquid in a flow path from a supply port to a pressure chamber.

  The present invention includes a pressure chamber capable of storing a liquid therein, an energy generating element for applying energy to the liquid stored in the pressure chamber, and a liquid to which energy is applied by the energy generating element. A discharge port for discharging, a supply port for supplying a liquid to the inside of the pressure chamber, and a flow path for flowing the liquid supplied from the supply port to the pressure chamber, facing the flow path By forming the surface rough at the position, a rough surface is formed in which the flow velocity of the liquid flowing through the flow path is increased as compared with the case where the surface is smooth.

  According to the present invention, since the speed of liquid refill after the liquid is discharged can be increased, the liquid discharge frequency by the liquid discharge head can be increased. Therefore, the amount of recording that can be recorded per unit time can be increased, and recording can be performed more efficiently.

1 is a perspective view showing an ink jet recording apparatus using a recording head according to a first embodiment of the present invention. FIG. 2 is a perspective view showing an internal configuration of a recording head used by the ink jet recording apparatus of FIG. FIGS. 3A and 3B are cross-sectional views of the recording head showing respective states until bubbles are generated and liquid is discharged and the liquid is refilled again when liquid is discharged by the recording head of FIG. 2. FIG. 3 is a cross-sectional view illustrating a manufacturing process of the recording head of FIG. 2. It is sectional drawing shown about the manufacturing process of the recording head which concerns on 2nd Embodiment of this invention. It is sectional drawing shown about the manufacturing process of the recording head which concerns on 3rd Embodiment of this invention.

(First embodiment)
Hereinafter, an ink jet recording apparatus (liquid ejection apparatus) according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an ink jet recording apparatus 1 according to an embodiment of the present invention. An ink cartridge 6 for storing ink to be supplied to the recording head 3 is mounted on the carriage 2 of the ink jet recording apparatus 1 together with the recording head 3 as a liquid ejection head of the present invention. The ink cartridge 6 is detachable from the carriage 2. Note that the recording head 3 and the ink cartridge 6 may be integrally formed.

  The ink jet recording apparatus 1 is capable of color recording, and the carriage 2 contains four ink cartridges 6 containing inks of respective colors of magenta (M), cyan (C), yellow (Y), and black (K). It is equipped with. These four ink cartridges 6 can be attached and detached independently.

  The carriage 2 and the recording head 3 are electrically connected to each other when the electrical contact portions between the two members are in proper contact with each other. The recording head 3 performs recording by selectively ejecting ink from a plurality of ejection ports onto a recording medium (medium) by applying energy according to a recording signal. In particular, the recording head 3 of the present embodiment employs an ink jet system that ejects ink using thermal energy.

  In the ink jet recording apparatus 1, a guide shaft 13 is disposed so as to extend along the main scanning direction of the carriage 2. The carriage 2 is penetrated and supported by the guide shaft 13. Accordingly, the carriage 2 is guided and supported so as to be slidable in the direction of arrow A along the guide shaft 13.

  The carriage 2 is connected to a part of a driving belt 7 as a transmission mechanism for transmitting a driving force from a carriage motor. The carriage 2 on which the recording head 3 is mounted is reciprocated by the driving force of the carriage motor. As described above, the carriage 2 reciprocates in the main scanning direction that intersects the conveyance direction of the recording medium along the guide shaft 13 by normal rotation and reverse rotation of the carriage motor. Further, the inkjet recording apparatus 1 is provided with a scale (not shown) for indicating the position of the carriage 2 along the movement direction (arrow A direction) of the carriage 2. Ink is discharged while the recording head 3 scans in the main scanning direction, so that recording is performed over the entire width of the recording medium P. Further, the inkjet recording apparatus 1 is provided with a platen so as to face the ejection port surface where the ejection port of the recording head 3 is formed.

  The ink jet recording apparatus 1 includes a transport roller 14 that is driven by a transport motor (not shown) to transport the recording medium P. The inkjet recording apparatus 1 is connected to a pinch roller 15 that contacts the recording medium P with the conveyance roller 14 by a spring (not illustrated), a pinch roller holder (not illustrated) that rotatably supports the pinch roller 15, and the conveyance roller 14. In addition, a conveyance roller gear (not shown) is included. When the transport motor rotates, the driving force by the rotational drive of the transport motor is transmitted to the transport roller 14 through the transport roller gear, and the transport roller 14 is driven. As described above, the ink jet recording apparatus 1 includes a transport unit that transports the recording medium. The recording medium P is transported along the transport direction by rotating the transport roller 14 with the recording medium P sandwiched between the transport roller 14 and the pinch roller 15.

  Further, the ink jet recording apparatus 1 is provided with a cap 226 that caps the ejection port of the recording head 3 and can receive the ink ejected from the recording head 3. Preliminary ejection with pigment ink is performed with the cap 226 capping the ejection port of the recording head 3, and the ink ejected by the preliminary ejection with the pigment ink can be collected by sucking the ink in the cap. Is possible. Further, a platen preliminary discharge position home 224 and a platen preliminary discharge position away 225 that can receive ink discharged when preliminary discharge is performed on the platen are arranged outside the recording medium P in FIG.

  FIG. 2 is a perspective view of the recording head 3 attached to the carriage 2 of the inkjet recording apparatus 1. The recording head 3 is formed by bonding a flow path forming member 21 to a substrate 20. A channel 12 and a pressure chamber 22 are defined between the substrate 20 and the channel forming member 21. The pressure chamber 22 can store a liquid such as ink inside. A supply port 11 is formed in the substrate 20 so as to penetrate the substrate 20. The channel 12 circulates the liquid supplied from the supply port 11 to the pressure chamber 22. Each of the flow paths 12 is provided with a heating resistance element (energy generating element) 13 as a means for generating energy used for discharging the liquid. When the heating resistor element 13 generates thermal energy, energy is applied to the liquid stored in the pressure chamber 22. A discharge port 23 is formed at a position corresponding to the heating resistance element 13 in each flow path 12 in the flow path forming member 21. Further, a partition wall 24 for separating the flow paths 12 is disposed between the flow paths 12.

  In the recording head 3 of the present embodiment, a plurality of grooves 14 are formed at positions facing the flow path 12 in the flow path forming member 21. Thus, a rough surface having a rough surface is formed by forming the groove 14 at a position facing the flow path 12 in the flow path forming member 21. In the present embodiment, the groove 14 is formed so as to extend along a direction intersecting the direction in which the liquid is supplied from the supply port 11 toward the discharge port 23. Further, the groove 14 faces the flow path 12 in the flow path forming member 21 and is formed only at a position facing the heating resistance element 13. However, the present invention is not limited to this, and the groove 14 may be formed at a position facing the end of the flow path 12 along the direction in which the liquid is supplied. Further, the groove 14 may be formed on the surface of the substrate 20 on which the heating resistor element 13 is disposed.

  As described above, in the present embodiment, the plurality of grooves 14 are formed at positions facing the flow path 12 in the flow path forming member 21, thereby forming a rough surface having a rough surface. The rough surface referred to here is a surface that is formed to be rough enough to reduce the contact angle of the liquid meniscus with respect to the wall surface of the flow path forming member 21 when the liquid flows through the flow path 12. That is, by forming the rough surface rougher than the smooth surface, the contact angle of the liquid meniscus with respect to the wall surface of the flow path forming member 21 is reduced. When the rough surface is formed to be excessively rough, the rough surface of the present embodiment does not act to reduce the contact angle of the liquid meniscus with respect to the wall surface. That is, in this embodiment, the rough surface is formed so rough that the wall surface is easily wetted.

  The shape of the groove 14 is a depth of 10% or less of the height of the flow path 12 in the flow path forming member 21 (the length of the flow path 12 along the direction in which the liquid is discharged from the discharge port 23). It is required to be. If irregularities with a height greater than 10% of the height of the flow path 12 are present in the flow path, conversely, the resistance to the liquid may increase. For this reason, the flow velocity during the movement of the liquid in the flow path becomes slow, and it may take much time for refilling. Preferably, about 1% of the liquid channel height is preferable. For example, when the liquid channel height is 10 μm, it is preferable that the groove 14 of about 0.1 μm to 1 μm is formed. In the present embodiment, the groove 14 is formed over the entire surface facing the surface on which the heating resistor element 13 is disposed, but is not limited to this, and faces the surface on which the heating resistor element 13 is disposed. It may be formed only on a part of the surface to be processed.

  When the liquid is ejected, a pulse voltage is applied to the heating resistor element 13 for generating thermal energy in the recording head 3. At this time, the heating resistor element 13 converts the applied electrical energy into thermal energy. By applying the thermal energy to the liquid present around the heating resistor element 13, film boiling occurs in the ink and bubbles are generated in the liquid. The liquid is discharged from the discharge port using the pressure change caused by the bubble growth and contraction at this time. In this way, a recording signal is given to the recording head 3 at a predetermined timing, and by driving the heating resistance element 13 disposed on the recording head 3, ink is ejected onto the recording medium and recording is performed.

  The recording head according to the present embodiment employs a system in which film boiling is generated by a heating resistor element and foamed to eject ink droplets, but the present invention is not limited to this. A recording head of a type that deforms a piezoelectric element and thereby discharges liquid inside the recording head may be applied to the recording apparatus, and another type of recording head may be applied to the recording apparatus of the present invention. .

  When the liquid is discharged from the discharge port, the liquid is filled again in the region where the liquid is once excluded in the flow path by generating bubbles, and the liquid is refilled in the flow path. The refilling of the liquid after the liquid is discharged is performed by supplying the liquid from the supply port 11 toward the pressure chamber 22. By supplying the liquid from the supply port 11 toward the pressure chamber 22, the meniscus as the liquid surface formed by the generation of the bubbles moves toward the discharge port 23, and the liquid is discharged into the region where the liquid is excluded by the bubbles. Is supplied again.

  In the present embodiment, the groove 14 is formed on the wall surface forming the flow path 12. Since the groove 14 is formed on the wall surface forming the flow path 12 in this way, the surface is formed rough, so that the flow velocity of the liquid flowing through the flow path is increased when refilling is performed after the liquid is discharged. Can do. Ink filling the pressure chamber 22 for refilling is performed with movement of the meniscus. During the movement of the meniscus, the meniscus is affected by the surface tension of the liquid and the force that keeps the contact angle small between the inner wall of the liquid passage. That is, when the liquid is refilled for refilling after the bubbles communicate with the atmosphere, the contact angle between the force to maintain the minimum area of the meniscus by the surface tension and the wall surface of the liquid passage 12 is reduced. The force to maintain greatly contributes to the movement of the meniscus. Attention is paid to the contact angle between the wall surface of the flow path 12 and the liquid at this time, and the refill speed can be positively improved by reducing the resistance of the wall surface of the flow path 12 to the liquid.

  The speeding up of this refill will be described. From the Wenzel equation, it is known that when the contact angle of the liquid is 90 ° or less, the meniscus has a property that the contact angle becomes smaller on a rough surface. With reference to FIGS. 3A to 3D, the movement of the liquid from when the liquid is ejected by the recording head 3 until the liquid is refilled will be described. In the recording head 3 in the state shown in FIG. 3A, when a pulse voltage is applied to the heating resistor 13, bubbles are generated by film boiling and discharged as shown in FIG. 3B. Liquid is discharged from the outlet 23.

  FIG. 3B shows the state of the liquid in the liquid path when the liquid is removed from the vicinity of the heating resistance element 13 due to the generation of bubbles, and the meniscus moves to the maximum along with this. . Thereafter, in the recording head 3 of the present embodiment, as shown in FIG. 3C, the bubbles communicate with the atmosphere. Thereafter, as shown in FIG. 3D, the liquid is refilled by refilling the portion where the liquid is removed by the bubbles.

  At the contact position of the meniscus with the wall surface at this time, the meniscus has a contact angle of 90 ° or less with respect to the wall surface. In the present embodiment, since the wall surface of the flow path forming member 21 facing the flow path 12 is formed rough, in a liquid having a contact angle of 90 ° or less, the meniscus becomes a direction in which the contact angle becomes smaller. A force acts on it. Therefore, the wall surface at the position facing the flow path 12 in the flow path forming member 21 is more easily wetted by the liquid. Therefore, a force in a direction toward the heating resistance element 13 and the discharge port 23 acts along the wall surface at a portion near the wall surface in the meniscus. Accordingly, the portion of the meniscus that is close to the wall surface moves in a direction toward the heating resistance element 13 and the discharge port 23 at a higher flow rate. Further, in a portion other than the portion near the wall surface in the meniscus, a force is applied to the meniscus so as to keep the minimum area by surface tension. Therefore, when a portion near the wall surface in the meniscus moves in a direction toward the heating resistor element 13 and the discharge port 23, the heating resistor element 13 and the discharge port 23 also move in a portion other than the portion near the wall surface in the meniscus so as to be pulled. Force in the direction of heading acts. Therefore, when liquid refilling is performed, a force in the refill direction toward the heating resistance element 13 and the discharge port 23 acts on the entire meniscus. Thereby, the moving speed of the meniscus when the liquid is refilled is increased, and the refill can be performed in a shorter time.

  Thus, in this embodiment, since the wall surface is coarsely formed by forming the groove 14 in a part of the wall surface facing the flow path 12, the flow velocity at the time of liquid movement by refilling is increased. Can do. Therefore, refilling of the liquid after the liquid is discharged can be performed in a short time. Thereby, recording at a high frequency becomes possible. As a result, the time required for recording can be shortened, so that recording can be performed efficiently, and the amount of recording that can be performed per unit time can be increased.

  Further, according to the present embodiment, it is possible to increase the speed of refilling with the liquid without changing the height of the flow path 12. Considering only increasing the refill speed, it is conceivable to reduce the resistance of the wall surface to the liquid by increasing the height of the flow path 12. However, when the height of the flow path 12 is increased in order to increase the refilling speed, the recording head 3 is enlarged accordingly. Further, as the recording head 3 becomes larger, the manufacturing cost of the recording head 3 also increases. In this embodiment, by smoothing the flow of the liquid during refilling without changing the height of the flow path 12, the resistance to the liquid by the wall surface of the flow path 12 is reduced, and the refill speed is reduced. Can be increased. Therefore, the refill time can be shortened without increasing the size of the recording head 3.

  Further, in order to improve the quality of a recorded image obtained by recording, it can be considered that the height of the ink flow path is formed low. Thereby, it is possible to suppress the occurrence of mist and splash during recording. However, when the height of the ink flow path in the recording head is formed low, the resistance from the wall surface to the ink in the ink flow path may increase. As a result, the refill time after the liquid is first ejected becomes long, and recording may take a long time. Thus, even when the height of the flow path is formed low in order to suppress the occurrence of mist and splash, it is possible to suppress an increase in refill time by applying the recording head of the present invention. . Therefore, it is possible to suppress the occurrence of mist and splash during recording while suppressing an increase in recording time. Therefore, the quality of the recorded image can be improved.

  Next, a method for manufacturing the recording head 3 will be described. 4A and 4B are schematic views showing the method of manufacturing the liquid discharge head in the order of steps, as seen from the cross-sectional direction of the broken line AA in FIG. Hereinafter, the manufacturing method of the present invention will be described step by step with reference to FIG.

  First, as shown in FIG. 4A, a substrate 20 on which a plurality of heating resistance elements 13 are formed is prepared. The substrate 20 is preliminarily formed with a drive circuit and wiring that connects the drive circuit and the heating resistor element. The substrate 20 is preferably a silicon single crystal substrate in order to facilitate the formation of a drive circuit and wiring. In the present embodiment, as shown in FIG. 4A, the heating resistor element 13 and the heating resistor element 13 are formed on one of the opposing surfaces of the silicon single crystal substrate with the ingot drawing orientation <100>. A substrate 20 on which a drive circuit and a wiring for driving are previously formed is prepared.

  Next, as shown in FIG. 4B, a resin layer (first layer) 33 that can be removed in a later step is formed in the region to be the flow path 12. As the material of the resin layer 33, a photosensitive material is desirable, and it is preferable to use a positive resist or a solubility-changing negative resist. As a method for forming the resin layer 33, there is a method in which this photosensitive material is dissolved in an appropriate solvent, and a film is formed by a spin coating method, a roll coating method or the like. The resin layer 33 is disposed at a position corresponding to the flow path 12 and the pressure chamber 22 corresponding to each heating resistance element 13. In the present embodiment, the resin layer is formed using a positive resist layer containing PMIPK as the resin material. A coating resist mainly composed of PMIPK is commercially available from Tokyo Ohka Kogyo Co., Ltd. under the product name: ODUR-1010. This resin layer can be formed by a general-purpose spin coating method. The resist layer is exposed and developed with an exposure machine having an exposure wavelength of 230 to 350 nm, whereby a pattern as shown in FIG. 4B is formed.

  Next, as shown in FIG. 4C, the resin is formed on the surface of the resin layer 33 so as to have a predetermined shape for the flow path forming member 21 to become the groove 14 when the resin layer 33 is removed. Processing for forming the irregularities 31 in the layer 33 is performed. As a processing method for forming the irregularities 31 to be the grooves 14 in the resin layer 33, processing methods such as grinding, blasting, chemical etching, ion milling, and RIE (Reactive Ion Etching) can be applied. It is. In the present embodiment, grinding is used as a method for forming the groove 14. Grinding is generally performed by removing a surface of a workpiece by rotating a grinding wheel called a grindstone at a high speed. When the irregularities 31 are formed on the surface of the resin layer 33, it is possible to remove a certain amount of the surface from one direction using a grindstone processed into a convex shape. In addition, the shape of the uneven | corrugated 31 formed can be arbitrarily formed by changing the shape of a grindstone. Further, as a method for forming the irregularities 31, a processing method such as blast processing, chemical etching processing, ion milling, or RIE may be used in addition to the above-described grinding processing.

  Next, as shown in FIG. 4D, a coating resin layer (second layer) 5 to be a subsequent flow path forming member 21 is applied on the resin layer 33 so as to cover the resin layer 33 by spin coating. It is formed by a roll coating method or the like. Here, in the step of forming the resin layer 5, the solvent used at this time needs characteristics such as not to deform the pattern of the removable resin layer 33. That is, when the resin layer 5 is once dissolved in a solvent and formed on the resin pattern 33 by spin coating, roll coating, or the like, the solvent is selected so that even the removable resin pattern 33 is not dissolved. It is necessary to The resin layer 5 is preferably made of a photosensitive material because the discharge port 23 can be easily and accurately formed by photolithography. From the above, it is desirable for the resin layer 5 to use a cationic polymerization cured product of an epoxy resin.

  Next, as shown in FIG. 4E, the discharge port 23 through which the liquid flies is formed. As described above, the forming method uses photolithography to apply a protective film (not shown) to the resin layer 5 in order to protect the material layer and to expose the resin layer 5. Next, a supply port 11 as an opening for supplying liquid is formed in the substrate. In the present embodiment, the supply port 11 is formed from the back surface of the substrate 20 for ease of processing. Finally, as shown in FIG. 4F, the resin layer 33 is removed to form a liquid discharge chamber.

  Through the above steps, the recording head 3 in which the groove 14 is formed at a position facing the flow path 12 is manufactured.

(Second Embodiment)
Next, a recording head according to the second embodiment will be described. In addition, about the part which can be comprised similarly to the said 1st Embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  The recording head of the second embodiment is formed so that the position of the groove 14 facing the flow path 12 has water repellency. This makes it possible to leave bubbles in the groove 14 when the liquid is refilled around the heat generating resistor element 13 after the liquid is once discharged.

  It is known that when there are bubbles in the vicinity of the wall surface, this reduces the resistance of the wall surface to the liquid. For this reason, by disposing a water-repellent member in the groove 14, air bubbles remain inside the groove 14, thereby reducing the resistance of the wall surface to the liquid. Since the refill is performed in a state where bubbles are present inside the groove 14, the resistance between the liquid and the wall surface of the flow path 12 is reduced, so that the refill speed can be improved and the discharge frequency can be further improved. Is possible. Thereby, recording can be performed efficiently.

  A manufacturing process of the recording head according to the second embodiment will be described with reference to FIGS. FIG. 5A to FIG. 5D are cross-sectional views showing respective manufacturing steps of the recording head in the second embodiment.

  In the manufacturing process of the recording head of the second embodiment, the resin layer 33 is disposed on the substrate, the resin layer is ground to form the grooves 14, and then the water repellent layer 8 is formed on the protruding portion of the resin layer 33. Are arranged (FIG. 5A). In the present embodiment, the water repellent layer 8 is a water repellent obtained by diluting a fluorocarbon compound with a solvent. In this state, the substrate 20 is dried and the water repellent layer 8 is solidified to form the water repellent member 30 having water repellency on the resin layer 33. Thereafter, as shown in FIG. 5B, in a state where the water repellent layer 8 is disposed on the resin layer 33, the resin layer 5 is disposed thereon.

  When the resin layer 5 is disposed, the discharge port 23 is formed by exposing the resin layer 5 as shown in FIG. When the discharge port 23 is formed in the resin layer 5, as shown in FIG. 5D, the resin layer 33 is removed and the supply port 11 is formed. By doing in this way, the water repellent member 30 can be formed in the position facing the flow path 12 in the groove | channel like letterpress printing. Thereby, a recording head in which the water repellent member 30 is formed at a position facing the flow path 12 in the groove 14 can be easily manufactured.

(Third embodiment)
Next, a recording head according to the third embodiment will be described. In addition, about the part which can be comprised similarly to said 1st embodiment, the same code | symbol is attached | subjected in a figure, description is abbreviate | omitted, and only a different part is demonstrated.

  In the manufacturing process of the recording head according to the third embodiment, the resin layer 5 serving as the flow path forming member 21 is formed on the resin layer 33 by chemical vapor deposition such as PECVD (Plasma Enhanced CVD). In the manufacturing process of the recording head of the third embodiment, by using PECVD, the groove formed in the resin layer 33 in which the groove is formed is formed such that the groove is transferred to the resin layer 5. Unevenness is also formed on the surface of 21.

  In this embodiment, since the resin layer 5 is formed by PECVD, it is necessary to select a material that can withstand the film formation temperature by PECVD as the material of the resin layer 33. In the present embodiment, polyimide (trade name: PI2611, manufactured by Hitachi Chemical DuPont Microsystems) is used as a material for forming the resin layer 33. Further, a metal material may be used as a material for forming the resin layer 33. In that case, aluminum or an aluminum alloy can be used in consideration of removability.

  With reference to FIGS. 6A to 6C, the manufacturing process of the recording head of the third embodiment will be described. 6A to 6C are cross-sectional views illustrating respective manufacturing steps of the recording head of the third embodiment.

  First, the resin layer 33 is formed on the substrate 20. In this embodiment, the resin layer 33 is applied onto the substrate 20 by spin coating, and then dehydrated and condensed in an oven. Thereafter, a positive photosensitive photoresist is applied, and the resin layer 33 is patterned into a desired pattern. Subsequently, polyimide is patterned by RIE mainly composed of oxygen, and then the photoresist is peeled off.

  Next, grooves having irregularities are formed on the surface of the resin layer 33. As a method for forming the groove, grinding is performed. As a method for forming the groove, other than grinding, blasting, chemical etching, ion milling, RIE, or other processing methods may be used.

  Thereafter, as shown in FIG. 6A, an inorganic material is formed by PECVD so as to cover the resin layer 33. In this embodiment, SiN is used as the inorganic material. Thereby, the part used as the flow path formation member 21 later is formed. Since the coating by PECVD has a property of being formed along the surface shape of the lower layer, the resin layer 5 is formed along the irregularities 31 on the surface of the resin layer 33.

  Next, as shown in FIG. 6B, the discharge port 23 is formed. Photoresist was applied on the orifice plate, and a mask was formed by patterning the position to be the discharge port. Subsequently, a part of the flow path generating member 12 formed of SiN was removed by RIE mainly composed of fluorine, and then the mask was peeled off. Next, after forming a protective layer for protecting the flow path forming member 21, the supply port 11 is formed on the side of the substrate 20 where the flow path forming member 21 is not formed.

  Next, as shown in FIG. 6C, the resin layer 33 formed of polyimide is removed by CDE mainly composed of oxygen. Thereby, a recording head is formed. If the material for forming the resin layer 33 is a metal material, wet etching is performed using a chemical that can dissolve the selected metal material. For example, when the metal material is aluminum, an etchant mainly composed of phosphoric acid is preferably used.

  In this embodiment, PECVD is used as the chemical vapor deposition method, but the present invention is not limited to this. Other methods may be used as long as the resin layer 5 for forming the flow path forming member 21 can be accurately formed.

  In the above-described embodiment, the rough surface formed at the position facing the flow path 12 is the plurality of grooves 14 extending in the direction intersecting the direction in which the flow path 12 extends, but the present invention is not limited to this. . As long as the surface has a larger area than the smooth surface and the surface is formed so as to increase the flow velocity of the liquid flowing through the flow path 12, the surface may not be a rough surface formed roughly by a groove extending in one direction. For example, it may be a rough surface formed roughly by irregular irregularities, or may be a rough surface formed rough by intersecting grooves extending in a plurality of directions. The rough surface may be formed by a plurality of grooves extending in parallel with the direction in which the flow path 12 extends.

  Moreover, in the said embodiment, although the rough surface by forming the groove | channel 14 was formed in the position which faced the flow path 12 in the flow path formation member 21, this invention is not limited to this. The rough surface may be formed at another position as long as it faces the flow path 12 from the supply port 11 toward the pressure chamber 22 and the flow rate of the liquid flowing through the flow path 12 can be increased. For example, a rough surface may be formed in a region between the supply port 11 and the heating resistor element 13 in the substrate 20 or may be formed at a position facing the side surface of the flow path 12 in the flow path forming member 21. .

  In the above embodiment, the ink jet recording apparatus is a so-called serial scan type recording apparatus that records an image with movement of the recording head in the main scanning direction and conveyance of the recording medium in the sub scanning direction. However, the present invention is also applicable to a full-line type ink jet recording apparatus that uses a recording head that extends over the entire width of the recording medium.

  The recording head according to the present embodiment employs a system in which film boiling is generated by a heating element and foamed to eject ink droplets, but the present invention is not limited to this. A recording head of a type that deforms the piezoelectric element and thereby discharges the liquid inside the recording head may be applied to the recording apparatus. Other types of recording heads may be applied to the ink jet recording apparatus of the present invention.

  Further, in this specification, “recording” is used not only for forming significant information such as characters and figures but also regardless of significance. It also represents the case where images, patterns, patterns, etc. are widely formed on a recording medium, or the recording medium is processed, regardless of whether it is manifested so that it can be perceived by human eyes. And

  The “recording device” includes a device having a printing function such as a printer, a printer multifunction device, a copying machine, and a facsimile device, and a manufacturing device that manufactures an article using an ink jet technique.

  “Recording medium” means not only paper used in general recording apparatuses but also a wide range of materials that can accept ink, such as cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. Shall.

  Furthermore, “ink” (sometimes referred to as “liquid”) should be interpreted widely as in the definition of “recording”. By being applied on the recording medium, it can be used for formation of images, patterns, patterns, etc., processing of the recording medium, or ink processing (for example, solidification or insolubilization of the colorant in the ink applied to the recording medium). It shall represent a liquid.

3 Recording Head 11 Supply Port 12 Channel 13 Heating Resistance Element 22 Pressure Chamber 23 Discharge Port

Claims (11)

A pressure chamber capable of storing liquid inside;
An energy generating element that imparts energy to the liquid stored in the pressure chamber;
A discharge port for discharging a liquid to which energy is applied by the energy generating element;
A supply port for supplying a liquid into the pressure chamber;
A flow path for circulating the liquid supplied from the supply port to the pressure chamber,
A liquid discharge head characterized in that a rough surface is formed at a position facing the flow path so as to make a contact angle with the liquid flowing through the flow path smaller than when the surface is smooth.   The liquid discharge head according to claim 1, wherein the rough surface is formed rough by forming a plurality of grooves in the same direction on the surface.   The liquid ejection head according to claim 2, wherein the groove is formed along a direction intersecting a direction in which the flow path extends.   4. The liquid discharge head according to claim 2, wherein a water repellent member having water repellency is disposed at a position facing the flow path in the groove. 5.   5. The liquid ejection head according to claim 2, wherein a depth of the groove is 10% or less of a length along a direction in which the liquid is ejected in the flow path.   6. The liquid ejection head according to claim 2, wherein a depth of the groove is 1% of a length along a direction in which the liquid is ejected in the flow path. The discharge port is formed at a position facing the energy generating element,
The said rough surface is formed in the surface by which the said discharge port was formed among the surfaces which define the said pressure chamber and the said flow path, The any one of Claim 1 to 6 characterized by the above-mentioned. The liquid discharge head described in 1. It has a liquid discharge head given in any 1 paragraph of Claims 1-7,
A liquid ejection apparatus that ejects liquid onto a medium by the liquid ejection head. A pressure chamber capable of storing a liquid is defined by having the substrate and the flow path forming member, and the substrate and the flow path forming member are joined together, and the pressure chamber is stored in the pressure chamber. An energy generating element for applying energy to the liquid, a discharge port for discharging the liquid to which energy is applied by the energy generating element, a supply port for supplying the liquid into the pressure chamber, and the supply port A liquid discharge head manufacturing method having a flow path for circulating the liquid supplied to the pressure chamber from
Disposing a first layer that can be removed later at a position to be the flow path on the substrate;
Forming in the first layer a shape corresponding to a roughened surface;
Forming a second layer to be the flow path forming member so as to cover the first layer;
And a step of forming the flow path facing the rough surface on the flow path forming member by removing the first layer. A step of forming a water repellent layer having water repellency on the first layer after the step of forming a shape corresponding to a rough surface to be formed on the first layer;
The method of manufacturing a liquid ejection head according to claim 9, further comprising: forming the second layer so as to cover the first layer on which the water repellent layer is disposed.   In the step of forming the second layer to be the flow path forming member so as to cover the first layer, the second layer is formed by chemical vapor deposition so as to cover the first layer. The method of manufacturing a liquid discharge head according to claim 9, wherein the liquid discharge head is formed.

Images