JP2005066995A - Chip for ink jet recording head, ink jet recording head having that chip, ink jet recorder having that ink jet recording head, and manufacturing process of chip for ink jet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip for an ink jet recording head reduced in size and exhibiting a high cooling efficiency, an ink jet recording head having that chip, an ink jet recorder having that ink jet recording head, and a manufacturing process of the chip for an ink jet recording head. <P>SOLUTION: A heating element side substrate 14 provided with heating elements for ejecting an ink drop is formed while being arranged on a wafer. A groove 84 against which cooling liquid abuts is formed on the back side of the wafer and a cooling water channel 100 for passing cooling water is formed by covering the groove 84 from the outside with a polyimide film 92 having a cooling water inlet 94I and a cooling water exit 94E communicating with the groove 84. Since the cooling water cools the substrate 14 by abutting against it directly, heat can be removed easily from the heating element side substrate 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording head chip having a cooling mechanism, an ink jet recording head having the ink jet recording head chip, an ink jet recording apparatus having the ink jet recording head, and a method for manufacturing the ink jet recording head chip.

  In recent years, inkjet recording apparatuses have attracted attention as low-cost, high-quality color recording apparatuses. As an ink jet recording head of an ink jet recording apparatus, for example, a thermal type ink jet recording head is known in which current is supplied to a heating element disposed in an individual flow path and ink is ejected from a nozzle with a pressure that vaporizes the ink. (For example, refer to Patent Document 1).

  By the way, in the conventional ink jet recording apparatus, if the temperature of the ink jet recording head rises too much due to the recording operation, the recording density changes or recording unevenness occurs, and the operation becomes unstable, and ink is discharged. It can happen even if it is not done. Further, in the case of color printing, there is a variation in the mixing ratio of the inks of the respective colors, resulting in a situation where the hue varies. This is particularly noticeable when high-speed printing is performed.

  For this reason, various cooling mechanisms for cooling the ink jet recording head have been proposed. For example, in Patent Document 2, in a thermal ink jet recording head, a temperature detection element is provided on a printed circuit board provided in the ink jet recording head, and a heat radiating member is brought into contact with the ink jet recording head from the outside to perform air cooling and temperature detection. It is disclosed that the element and the heat radiating member are coupled by a thermal coupling means having good thermal conductivity.

  Further, in Patent Document 3, a silicon wafer provided with an electrothermal transducer such as a heater is fixed on a head base having cooling fins formed on the outside, and the heat radiation efficiency is increased from the cooling fins.

In Patent Document 3, a base plate having good thermal conductivity is provided in the ink jet recording head. And the cooling mechanism comprised by the water jacket attached to the back side of this baseplate and the circulation mechanism which circulates the cooling water in a water jacket is provided.
JP 9-226142 A JP-A-6-255111 JP-A-5-330207 JP-A-8-72249

  However, Patent Documents 2 and 3 have a problem that it is difficult to reduce the size of the ink jet recording head because cooling members such as a heat radiating member and a head base are provided outside the ink jet recording head. Moreover, since it is air cooling, there also existed a problem that heat dissipation efficiency was low compared with water cooling.

  Moreover, in patent document 4, since the cooling mechanism was provided outside the inkjet recording head, there was a problem that it was difficult to reduce the size of the inkjet recording head.

  In consideration of the above-described facts, the present invention is an ink jet recording head chip that is downsized and has high cooling efficiency, an ink jet recording head having the ink jet recording head chip, an ink jet recording apparatus having the ink jet recording head, and an ink jet It is an object of the present invention to provide a method for manufacturing a recording head chip.

  As shown in FIG. 29, the present inventor has a conventional structure in which cooling is performed by a heat sink 204 joined from the outside of the inkjet recording head 202, and the cooling efficiency is poor because the head substrate 206 of the inkjet recording head 202 is thick. Pay attention.

  Accordingly, the present inventor considered that an ink jet recording head is not cooled from the outside, but provided a cooling mechanism inside the ink jet recording head, and further studied and completed the present invention.

  The invention described in claim 1 is characterized in that a heating element side substrate having a heating element for ejecting ink droplets and contacting a cooling fluid on the back side is provided.

  Thus, in the first aspect of the present invention, the cooling fluid directly cools against the heating element side substrate, so that it is easy to remove heat from the heating element side substrate. Therefore, a small inkjet recording head chip with high cooling efficiency can be realized.

  According to a second aspect of the present invention, there is provided a liquid circulation mechanism that circulates a liquid as the fluid.

  Thereby, the cooling efficiency is higher than that of air cooling, and by circulating this liquid, it is not necessary to discharge the liquid, and a reduction in size and cost can be realized.

  According to a third aspect of the present invention, a groove is formed on the back side of the heating element side substrate, and a shielding film that covers the groove from the outside is provided. The shielding film has a liquid inlet and a liquid that communicate with the groove. A cooling flow path through which the liquid flows is formed by forming the outlet.

  Thereby, most of the cooling flow path can be formed by the wall surface of the heating element side substrate, and the cooling fluid can efficiently absorb heat. About the shape of a groove | channel, it is preferable that it is a shape which can cool a heat generating element side board | substrate efficiently.

  The invention described in claim 4 is characterized in that a piezo element is provided in the liquid circulation mechanism, and the liquid flows and circulates through the cooling flow path by vibration of the piezo element.

  Thereby, the structure of the liquid circulation mechanism can be simplified and reduced in size. Further, the flow rate of the cooling liquid can be increased by vibrating the piezoelectric element at a high frequency.

  In the invention according to claim 5, the flow path height of the cooling flow path is within a range of 1/100 to 2/3 of the thickness of the heating element side substrate, and the flow path width of the cooling flow path. Is in the range of 5 to 500 μm.

  As a result, the groove can be formed into a microchannel structure to reduce the height of the cooling flow path, and further miniaturization of the inkjet recording head chip can be achieved. In addition, when the flow path height of the cooling flow path is within a range of 1/100 to 2/3 of the thickness of the heating element side substrate, the flow path height of the cooling flow path is several μm to several hundred μm. Often within range. If the flow channel height and width of the cooling flow channel are within this range, the groove is usually a micro channel.

  The invention described in claim 6 is characterized in that the cooling means causes an aqueous medium to flow as the liquid.

  As a result, it is possible to realize an ink jet recording head chip that uses an inexpensive medium having a large specific heat as the cooling liquid.

  The invention described in claim 7 is characterized in that the cooling means flows an ink liquid to be ejected as the liquid.

  Thereby, it is not necessary to newly provide a cooling medium for cooling the heating element side substrate.

  In addition, since the ink liquid is heated by cooling the heat generating element side substrate with the ink liquid, it is possible to reduce the amount of heat generated by the heat generating element when ejecting ink droplets. This effect becomes particularly remarkable when the heating element side substrate is cooled by the ink liquid in the ink liquid chamber formed in the ink jet recording head chip.

  The invention described in claim 8 is characterized in that air-cooling fins are formed on the back side of the heating element side substrate.

  Thus, in the invention according to the eighth aspect, since the heating element side substrate is directly air-cooled, the temperature rise of the heating element side substrate can be efficiently suppressed even with air cooling. Moreover, since it is air cooling, a cooling mechanism can be simplified.

  The invention according to claim 9 is characterized in that the height of the fin is within a range of ½ to 8/11 of the thickness of the heating element side substrate, and the width of the fin is 500 μm or less. To do.

  Thereby, a fin can be reduced in size.

  According to a tenth aspect of the present invention, an ink jet recording head includes the ink jet recording head chip according to any one of the first to ninth aspects.

  As a result, it is possible to realize an ink jet recording head that can perform good recording on a recording medium even if the amount of heat generated by the ink jet recording head chip is large.

  According to an eleventh aspect of the present invention, the ink jet recording head according to the tenth aspect is provided.

  As a result, even if the amount of heat generated by the ink jet recording head chip is large, the ink jet recording head can perform good recording on the recording medium, so that high speed printing is possible.

  According to a twelfth aspect of the present invention, a heating element side substrate provided with a heating element for discharging ink droplets, and a cooling liquid is brought into contact with the heating element side substrate to cool the heating element side substrate. And a cooling means for forming an ink jet recording head chip, wherein a groove for contacting the liquid is formed on the back side of the wafer substrate on which the heating element side substrate is formed in an arrayed state. The cooling channel through which the liquid flows is formed by sticking the groove so as to cover the groove from the outside with a shielding film in which a liquid inlet and a liquid outlet communicating with the groove are formed.

  Thereafter, a plurality of inkjet recording head chips can be obtained simultaneously by dicing performed in forming a general inkjet recording head chip.

  According to the invention of the twelfth aspect, the cooling channel as described above can be easily formed. When a cooling liquid is caused to flow through the cooling flow path formed in this manner, the liquid directly contacts the heating element side substrate and cools, so that it is easy to remove heat from the heating element side substrate. In addition, when forming a groove | channel, you may form by dry etching. Thereby, the shape of a groove | channel can be formed in arbitrary shapes, such as a microchannel.

  The invention described in claim 13 is characterized in that the shielding film is made of a resin, and the heating element side substrate and the shielding film are bonded by anodic bonding.

  Thereby, this pasting can be easily performed at low cost.

  According to a fourteenth aspect of the present invention, there is provided an ink jet recording head chip comprising: a heat generating element side substrate provided with a heat generating element for discharging ink droplets; and a cooling means for air-cooling the heat generating element side substrate. The method is characterized in that fins are formed by forming grooves on the back side of the wafer substrate on which the heating element side substrates are formed in an arrayed state.

  Thereby, the fin for air cooling can be easily formed with high precision.

  The invention described in claim 15 is characterized in that the groove is formed by dry etching.

  Thereby, it is easy to form a fin shape into an arbitrary shape. Moreover, the space | interval of adjacent fins can be set arbitrarily and the arrangement position and density of a fin can be set arbitrarily. As the dry etching, for example, reactive ion etching is performed. Thereby, since a highly accurate fin structure can be formed, the effect that a highly efficient fin structure can be formed can be produced.

  The invention described in claim 16 is characterized in that the width of the fin is 500 μm or less, and the height of the fin is in the range of 1/2 to 8/11 of the thickness of the heating element side substrate.

  Thereby, since the fin volume required for cooling is obtained, the effect that a highly efficient fin structure can be formed can be produced.

  Since the present invention has the above-described configuration, it is possible to realize an ink jet recording head chip that is downsized and has high cooling efficiency, an ink jet recording head having the ink jet recording head chip, and an ink jet recording apparatus having the ink jet recording head. . In addition, a cooling flow path can be easily formed in the heating element side substrate of the inkjet recording head chip.

  Hereinafter, embodiments will be described and embodiments of the present invention will be described. In the second and subsequent embodiments, the same components as those already described are denoted by the same reference numerals and description thereof is omitted.

[First Embodiment]
First, the first embodiment will be described. In the present embodiment, an inkjet recording head 10 (see FIG. 4) is provided in an inkjet recording apparatus 11 as shown in FIG. 1, and the inkjet recording head 10 includes an inkjet recording head chip (hereinafter, for simplicity). 12 is simply provided).

  As shown in FIG. 2, the inkjet recording head chip 12 includes an ink flow path side substrate 16 in which an ink flow path is formed, and a driving element such as a heat generating element 20 (see FIG. 3B) for discharging ink. It is formed by laminating a heating element side substrate 14 provided.

  A protective layer 18 for protecting the wiring and the like from the ink is formed on the surface of the heating element side substrate 14, and a heating element 20 for heating the ink and discharging ink droplets is disposed on a part of the protective layer 18. ing.

  On the other hand, as shown in FIGS. 3A and 3B, ink is supplied to the ink flow path side substrate 16 laminated on the heating element side substrate 14 to the nozzles 22 opened on the lamination end surface (nozzle end surface) 16A. An individual flow path 24 is formed, and an ink liquid chamber 26 communicating with each individual flow path is formed on the upstream side of the individual flow path 24. In the ink liquid chamber 26, a columnar body 27 is disposed in the vicinity of the individual flow path along the arrangement direction of the individual flow paths 24 with a substantially flow path width of the individual flow paths 24, and supplied from the ink liquid chamber 26 to the individual flow paths 24. The ink filter portion 28 is configured. Therefore, even if a foreign substance that blocks the individual flow path 24 enters the ink liquid chamber 26, it is trapped by the filter unit 28 and does not block the individual flow path 24, and ink is stably supplied to the individual flow path 24. .

  In addition, a large number of ink supply ports 30 are formed on the upper surface 16B orthogonal to the laminated end surface 16A of the ink flow path side substrate 16. The ink supply port 30 also has a trap structure that prevents foreign matters that flow from a sub ink tank 36 (described later) and block the individual flow path 24 from entering the ink liquid chamber 26. For example, the opening area of the ink supply port 30 is equal to or smaller than the cross-sectional area of the individual flow path 24, and the filter functions.

  The ink liquid chamber 26 communicates with the sub ink chamber 40 of the sub ink tank 36 through the ink supply port 30 by mounting the head chip 12 on the sub ink tank 36 described later.

  Note that notches 16D are formed at both ends in the longitudinal direction of the ink flow path side substrate 16 as shown in FIG. 2, and the input / output terminals 32 formed on the heating element side substrate 14 are exposed to the surface by the notches 16D. It is connected to the circuit of the heat sink 34 described later.

  As shown in FIG. 4, the head chip 12 formed in this way is mounted on the sub ink tank 36 to constitute the ink jet recording head 10. That is, the heat generating element side substrate 14 of the head chip 12 is fixed on the heat sink 34 and is pressed against the tip of the sub ink tank 36 via the elastic seal member 38, so that the ink liquid chamber 26 is formed in the sub ink tank 36. The sub ink chamber 40 communicates with the sub ink chamber 40. The sub ink chamber 40 is connected to an ink tank (not shown) via a filter 42.

  The sub ink tank 36 functions to supply ink from the ink tank to the ink liquid chamber 26, and the sub ink chamber 40 has a simple structure (substantially rectangular parallelepiped shape), thereby improving ink supply performance and ink discharge performance. In addition, since it has a sufficient capacity (cross-sectional area), it can perform the same function as the ink tank in that it can reliably supply ink to the ink liquid chamber 26 even if bubbles exist in the sub ink chamber.

  The ink jet recording head 10 including the head chip 12 formed as described above will be described together with a method for manufacturing the head chip.

  As a manufacturing method of the heating element side substrate 14, for example, it can be manufactured by using an LSI manufacturing technique and a manufacturing apparatus. Specifically, a heat storage layer, a heat generating layer to be a heat generating element, a protective layer for preventing the heat generating element from being damaged by the pressure of bubbles generated by the heat generated by the heat generating element, and the like are laminated on the single crystal silicon wafer 58 (FIG. 5). (See (A)). In addition, a signal line for supplying electric power and signals from the outside is connected to the heat generating layer. Similarly provided driver circuit 52, signal processing circuit 54, and external signal input / output terminal 32 are formed for a plurality of heads simultaneously. Further, a resin layer 56 such as photosensitive polyimide is laminated as a protective layer for the ink (see FIG. 5B). Further, as will be described later, a microchannel 84 (see FIG. 10) is formed on the back side of the silicon wafer 58.

  On the other hand, the ink flow path side substrate 16 can also be produced in the same manner as the heating element side substrate 14. Specifically, grooves 60, 62, and 64 that form the ink liquid chamber 26, the ink supply port 30, and the notch 16D are formed on the silicon wafer 50 by, for example, crystalline anisotropic etching (FIG. 5C). )reference). Furthermore, the groove | channel 66 used as the separate flow path 24 is formed by a well-known method by reactive ion etching (Reactive Ion Etching: RIE) (refer FIG.5 (D)).

  Further, the two silicon wafers 50 and 58 are accurately aligned with reference to the alignment marks 70 and 72 and bonded by a known method (see FIGS. 5E and 5F).

  Hereinafter, the above manufacturing process will be described in detail with a focus on forming the cooling channel 100 on the back side of the heating element side substrate 14 in particular. For simplification, in FIG. 6 and subsequent figures, the drawing of the filter-like part forming the ink liquid chamber 30 is omitted.

  First, the flat silicon wafer 50 (see FIG. 6) is processed by etching to form the recess 116 and the ink supply port 30 for forming the ink liquid chamber 26 (see FIG. 7).

  Then, a laminated wafer 78 is formed by laminating the silicon wafer 58 provided with the heat generating elements 20 and the like with the concave portion 116 facing inside (see FIG. 8). As a result, the ink liquid chamber 26 is formed by the silicon wafer 50 and the silicon wafer 58.

  Next, as shown in FIG. 9, a protective film 80 is pasted on the ink supply port side of the laminated wafer 78 in order to close the ink supply port 30. Further, a resist film is formed on the back surface side of the silicon wafer 58 and patterned into a microchannel shape by exposure processing to form a resist mask 82. The resist film is formed by, for example, coating, spraying, or spin coating.

  Further, by performing dry etching (for example, reactive ion etching) on the resist mask 82, the microchannel 84 as shown in FIGS. 10A and 10B is formed. Then, the resist mask 82 is removed. The microchannel 84 forms a cooling water passage 100 (see FIG. 15) described later.

Further, in order to close the upper surface side of the microchannel 84 in the drawing and form the cooling water flow path 100, the protective substrate 98 (see FIG. 13) is manufactured as follows. First, a protective sacrificial layer 90 is formed on a bare silicon wafer 88 to protect a polyimide film 92 described later. The protective sacrificial layer 90 is, for example, a SiO ₂ film or a Si ₃ N ₄ film. Then, a polyimide film 92 is formed on the protective sacrificial layer 90 (see FIG. 11).

  Further, a resist film containing silicon is formed, and openings 96I and 96E for forming a cooling water inlet 94I and a cooling water outlet 94E (both see FIG. 15) are patterned by exposure processing to form a resist mask. 96 is formed (see FIG. 12). The openings 96I and 96E may be formed by forming a photosensitive polyimide film and performing an exposure process.

  Next, holes 92I and 92E penetrating the polyimide film 92 are formed by dry etching (for example, reactive ion etching) as shown in FIG. The protective sacrificial layer 90 is exposed at the bottom of the holes 92I and 92E. Then, the resist mask 96 is removed to form a protective substrate 98.

  Thereafter, as shown in FIG. 14, the protective substrate 98 is anodically bonded to the side where the microchannel 84 of the laminated wafer 78 is formed, with the side where the holes 92I and 92E are opened inside, that is, a polyimide film. 92 and the upper end surface of the microchannel 84 are anodically bonded. At that time, the openings of the holes 92I and 92E are joined to the end positions of the microchannel 84, respectively. The method of anodic bonding is performed by a known method (for example, a method disclosed in Japanese Patent Application Laid-Open No. 2001-12799). As a result, the upper surface side of the paper surface of the microchannel 84 is covered with the polyimide film 92 except for the region where the holes 92I and 92E are formed, and the cooling water flow path 100 through which the cooling water flows is formed.

  Next, grinding and single-side anisotropic etching are performed from the protective substrate 98 side to remove the silicon wafer 88, and further, the protective sacrificial layer 90 is removed (see FIG. 15). At this time, since the protective sacrificial layer 90 is formed, the polyimide film 92 is prevented from being damaged when grinding is performed. Further, the removal of the protective sacrificial layer 90 opens the holes 92I and 92E on the upper side of the drawing, which become the cooling water inlet 94I and the cooling water outlet 94E, respectively.

  In this way, the wafer 104 with the cooling water flow path in which the cooling water inlet 94I and the cooling water outlet 94E are formed is cut and separated along the dicing line 74 in a known manner to form a plurality of heads. The chip 12 is manufactured at the same time (see FIGS. 5F and 16). By this cutting (dicing), the end of the individual flow path 24 is opened, and the nozzle 22 is configured to eject ink droplets. As shown in FIG. 16, a cooling water channel 100 is formed in the head chip 12 on the back side of the heating element side substrate 14.

  As a result, even when heat is generated from the heating element 20 or the like when the head chip 12 is used, the cooling water is passed through the cooling water channel 100 formed in the heating element side substrate 14 to directly connect the heating element side substrate 14. Therefore, the amount of heat removed from the head chip 12 is large. Therefore, even if the number of ejections per unit time of the ink droplets D from the head chip 12 is increased in order to perform printing at high speed, it is possible to sufficiently prevent the temperature of the heating element side substrate 14 from rising excessively.

  Therefore, even if the ink droplets D are ejected at a high repetition rate (high frequency) from the ink jet recording head 10 using the head chip 12, it is possible to avoid the recording density from being changed or the occurrence of recording unevenness.

  In addition, the ink jet recording apparatus 11 using the ink jet recording head 10 can record a good image at high speed even in color printing.

[Second Embodiment]
Next, a second embodiment will be described. In the second embodiment, the shape and number of cooling water flow paths are different from those in the first embodiment.

  That is, in the second embodiment, a large number of microchannels 128 are formed along the short direction of the head chip on the back side of the heating element side substrate 124 of the inkjet recording head chip (see FIG. 17).

  Then, after the polyimide film is attached in the same manner as in the first embodiment, the cooling water inlet 134I and the cooling water outlet 134E are formed for each microchannel (see FIG. 18). As a result, a number of short cooling water passages 130 are formed in the heating element side substrate 124.

  Therefore, the flow rate of the cooling water flowing through the cooling water flow path 130 of the heating element side substrate 124 can be made much larger than that of the first embodiment, and the amount of heat that can be removed per unit time can be greatly increased. .

[Third Embodiment]
Next, a third embodiment will be described. As shown in FIG. 21, in the third embodiment, a pump unit 136 for circulating cooling water from the cooling water inlet 94I to the cooling water outlet 94E is supplied to the inkjet recording head chip 12 manufactured in the first embodiment. It is attached from the side where the polyimide film 92 is formed.

  The pump unit 136 is provided with a circulation force applying member 140 that circulates the cooling water from the cooling water inlet 94I to the cooling water outlet 94E. The circulation force imparting member 140 is a diaphragm-shaped member having a shallow bottom, and has a recess 146 in which cooling water is stored. When the pump portion 136 is attached, the periphery of the recess 146 is in close contact with the polyimide film 92, and the space in the recess 146 communicates with the cooling water inlet 94I and the cooling water outlet 94E. .

In addition, two ribs 142 and 144 are erected substantially parallel from the substantially center position of the bottom surface of the recess 146. Each of the ribs 142 and 144 has an elongated shape in a direction orthogonal to the paper surface, that is, a direction orthogonal to a straight line connecting the cooling water inlet 94I and the cooling water outlet 94E, and the width t _{1 of the} rib 142 far from the cooling water inlet 94I is: It is shorter than the width t _{2 of the} rib 144 close to the cooling water inlet 94I. Further, the gaps between the upper ends of the ribs 142 and 144 and the heating element side substrate polyimide film 92 are substantially the same.

  Furthermore, a PZT (piezo element) 150 is attached to the circulation force applying member 140 from the outside. The attachment position of the PZT 150 is a substantially central position of the circulating force application member 140 and is a position between the rib 142 and the rib 144.

  In order to manufacture the inkjet recording head chip 152 according to the third embodiment, the wafer 141 with the circulation force applying member formed by arranging the circulation force applying member 140 on the wafer is manufactured (see FIG. 19). Then, the circulating force imparting member wafer 141 is joined to the side where the cooling water channel 100 is formed of the wafer 104 with the cooling water channel (see FIG. 15) described in the first embodiment (see FIGS. 19 and 20). .

  Thereafter, dicing is performed to simultaneously obtain a plurality of inkjet recording head chips 152.

  Due to the structure of the inkjet recording head chip 152 described above, when the PZT 150 vibrates, the circulating force imparting member 140 vibrates, and the cooling water stored in the concave portion 146 is moved from the cooling water inlet 94I by the vertical movement of the ribs 142 and 144. It flows through the cooling water flow path 100 and circulates so that it flows in and flows out from the cooling water outflow inlet 94E.

  Thus, in the third embodiment, it is possible to simplify the cooling mechanism by adopting a configuration for circulating the cooling water, and it is possible to simplify and reduce the size of the circulating pump mechanism.

  Note that a pump unit driven by a micro machine may be provided instead of the pump unit 136 driven by the PZT 150.

[Fourth Embodiment]
Next, a fourth embodiment will be described. As shown in FIG. 22, a large number of cooling fins 166 protrude from the back side of the heating element side substrate 164 constituting the inkjet recording head chip 162 according to the fourth embodiment by processing the microchannel. . The cooling fin 166 may have a pin shape.

  The width and height of the cooling fin 166 are about several hundreds μm in the present embodiment, but the practical ranges are within the range of several μm to several hundreds μm and several hundreds μm or less, respectively. is there.

  In order to form the cooling fins 166, the back surface side of the heating element side substrate 164 is performed by dry etching (for example, reactive ion etching). Thereby, the cross-sectional shape of the cooling fin 166 to be formed becomes uniform in the height direction, and there is no height restriction due to the width of the cooling fin as in the case of wet anisotropic etching. Therefore, the height of the cooling fin 166 can be made sufficiently high.

  As described above, in the fourth embodiment, even if air cooling is performed, the heating element side substrate 164 is directly cooled, so that the temperature rise of the heating element side substrate 164 can be efficiently suppressed. Moreover, since it is air cooling, a cooling mechanism can be simplified.

[Fifth Embodiment]
Next, a fifth embodiment will be described. As shown in FIG. 28, the inkjet recording head chip 172 according to the fifth embodiment includes a pump unit 176 similar to the pump unit 136 described in the third embodiment. The pump unit 176 is attached to the back side of the heating element side substrate 174 constituting the ink jet recording head chip 172, and the ink liquid in the ink liquid chamber 26 formed in the ink jet recording head chip 172 is removed by the PZT 170. The heat generating element side substrate 174 is circulated to the back side to be cooled.

  Note that a microchannel 184 similar to the microchannel 84 described in the first embodiment or the third embodiment is formed on the back surface side of the heating element side substrate 174. The heating element side substrate 174 is formed with two through holes 194 </ b> I and 194 </ b> E communicating with the ink liquid chamber 26 and both ends of the microchannel 184.

  To manufacture the inkjet recording head chip 172, first, the laminated wafer 78 is manufactured in the same manner as in the first embodiment (see FIG. 23).

Next, as shown in FIG. 24, a protective film 178 is attached to the side where the ink supply port 30 is formed. Then, a SiO2 film is formed by deposition on the back side of the silicon wafer on which a large number of heating element side substrates 174 are arranged, and further a resist film is applied by spraying or spin coating to form a microchannel. A resist pattern having openings is formed and dry etching is performed. As a result, a SiO ₂ film mask 180 is formed. Further, the resist film on which the resist pattern is formed is removed.

Next, a metal film is formed on the side where the SiO ₂ film mask 180 is formed. The film is formed by deposition or sputtering. Examples of the metal to be formed include Al, Ni, and Cr.

Further, a resist pattern is formed in the same manner as when the SiO ₂ film mask 180 is formed. The resist pattern at this time is a pattern in which openings corresponding to the through holes 194I and 194E are formed. Then, dry etching is performed. As a result, a metal mask 182 is formed. Further, the resist film on which the resist pattern is formed is removed (see FIG. 25).

Further, the silicon wafer is subjected to ICP reactive ion etching to form through holes 194I and 194E, and the metal mask 182 is removed by dry etching (see FIG. 26). As a result, the SiO ₂ film mask 180 is exposed.

Further, by performing ICP of the silicon wafer by reactive ion etching, a microchannel 184 similar to the microchannel 84 described in the first embodiment is formed. Then, the SiO ₂ film mask 180 is removed by dry etching, and the protective film 178 is peeled off (see FIG. 27).

  Further, as in the third embodiment, the pump 176 is provided on the side where the microchannel 184 is formed (see FIG. 28).

  In the ink jet recording head chip 172 manufactured in this way, the PZT 170 is driven, so that the ink liquid that flows into the ink liquid chamber 26 from the ink supply port 30 is stored and is stored on the back surface side of the heating element side substrate 174. It is possible to cool the heat generating element side substrate 174 by circulating the heat generating element side substrate.

  Thus, no cooling water is required when cooling the heating element side substrate 174. In addition, since the ink liquid is heated by cooling the heating element side substrate 174 with the ink liquid in the ink liquid chamber 26, the amount of heat generated by the heating element 20 (see FIG. 23B) can be reduced. It can be greatly reduced.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiment.

1 is a front perspective view of an ink jet recording apparatus according to a first embodiment. 1 is a perspective view of an inkjet recording head chip according to a first embodiment. 3A and 3B are a partial plan view and a partial side cross-sectional view of the inkjet recording head chip according to the first embodiment, respectively. 1 is a side cross-sectional view of an ink jet recording head according to a first embodiment. FIGS. 5A to 5F are schematic views illustrating the steps for manufacturing the inkjet recording head chip in the first embodiment. It is a substrate partial sectional view explaining manufacture of a chip for ink-jet recording heads in a 1st embodiment. It is a substrate partial sectional view explaining manufacture of a chip for ink-jet recording heads in a 1st embodiment. It is a substrate partial sectional view explaining manufacture of a chip for ink-jet recording heads in a 1st embodiment. It is a substrate partial sectional view explaining manufacture of a chip for ink-jet recording heads in a 1st embodiment. FIGS. 10A and 10B are a partial cross-sectional view of a substrate and a back view of arrows 10B-10B showing that a microchannel is formed in the first embodiment, respectively. It is a substrate partial sectional view explaining manufacture of a chip for ink-jet recording heads in a 1st embodiment. It is a substrate partial sectional view explaining manufacture of a chip for ink-jet recording heads in a 1st embodiment. It is a substrate partial sectional view explaining manufacture of a chip for ink-jet recording heads in a 1st embodiment. It is a substrate partial sectional view explaining manufacture of a chip for ink jet recording heads in a 1st embodiment. FIGS. 15A and 15B are a partial cross-sectional view of the substrate and a rear view of arrows 15B-15B showing that the cooling water flow path is formed in the first embodiment, respectively. It is side surface sectional drawing which shows the chip | tip for inkjet recording heads concerning 1st Embodiment. In 2nd Embodiment, it is the partial back view of the heat generating element side board | substrate which shows the groove | channel formed in the back surface side of the heat generating element side board | substrate. In 2nd Embodiment, it is the partial back view of the heat generating element side board | substrate which shows the flow path for cooling formed in the back surface side of the heat generating element side board | substrate. In 3rd Embodiment, it is a board | substrate partial sectional view which shows attaching the pump part which circulates cooling water to a cooling water flow path. In 3rd Embodiment, it is a board | substrate partial sectional view which shows having attached the pump part which circulates a cooling water to a cooling water flow path. It is side surface sectional drawing which shows the chip | tip for inkjet recording heads concerning 3rd Embodiment. It is a fragmentary sectional view showing the chip for ink jet recording heads concerning a 4th embodiment. FIGS. 23A to 23C are a partial perspective view of a substrate, a substrate partial cross-sectional view of 23B-23B, and a substrate of 23C-23C, showing the manufacture of the inkjet recording head chip in the fifth embodiment, respectively. It is a fragmentary sectional view. It is a substrate partial sectional view showing manufacture of a chip for ink-jet recording heads in a 5th embodiment. It is a substrate partial sectional view showing manufacture of a chip for ink-jet recording heads in a 5th embodiment. It is a substrate partial sectional view showing manufacture of a chip for ink-jet recording heads in a 5th embodiment. It is a substrate partial sectional view showing manufacture of a chip for ink-jet recording heads in a 5th embodiment. It is a fragmentary sectional view showing a chip for ink jet recording heads concerning a 5th embodiment. It is side surface sectional drawing which shows the chip | tip for the conventional inkjet recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Inkjet recording device 10 Inkjet recording head 12 Inkjet recording head chip 14 Heating element side substrate 84 Micro channel (groove)
92 Polyimide film (shielding film)
94I Cooling water inlet (liquid inlet)
94E Cooling water outlet (liquid outlet)
100 Cooling water channel (cooling channel)
128 Microchannel 130 Cooling water flow path (cooling flow path)
134I Cooling water inlet (liquid inlet)
134E Cooling water outlet (liquid outlet)
136 Pump part (liquid circulation mechanism)
150 PZT (piezo element)
152 Inkjet recording head chip 162 Inkjet recording head chip 164 Heating element side substrate 166 Cooling fin 170 PZT (piezo element)
172 Inkjet recording head chip 174 Heating element side substrate 176 Pump part 184 Microchannel (groove)

Claims (16)

  A chip for an ink jet recording head, comprising a heat generating element side substrate having a heat generating element for discharging ink droplets and contacting a cooling fluid on the back side.   The inkjet recording head chip according to claim 1, further comprising a liquid circulation mechanism that circulates a liquid as the fluid.   A groove is formed on the back side of the heating element side substrate, a shielding film is provided to cover the groove from the outside, and a liquid inlet and a liquid outlet that communicate with the groove are formed in the shielding film. The inkjet recording head chip according to claim 2, wherein a cooling flow path through which the liquid flows is formed.   4. The ink jet recording head chip according to claim 3, wherein the liquid circulation mechanism is provided with a piezo element, and the liquid flows and circulates through the cooling flow path by vibration of the piezo element.   The channel height of the cooling channel is in the range of 1/100 to 2/3 of the thickness of the heating element side substrate, and the channel width of the cooling channel is in the range of 5 to 500 μm. The inkjet recording head chip according to claim 3 or 4,   The inkjet recording head chip according to claim 2, wherein the cooling unit flows an aqueous medium as the liquid.   The inkjet recording head chip according to any one of claims 2 to 5, wherein the cooling means flows an ink liquid to be ejected as the liquid.   The inkjet recording head chip according to claim 1, wherein air-cooling fins are formed on a back side of the heating element side substrate.   9. The ink jet recording according to claim 8, wherein a height of the fin is within a range of [1/2] to 8/11 of a thickness of the heating element side substrate, and a width of the fin is 500 [mu] m or less. Head tip.   An inkjet recording head comprising the inkjet recording head chip according to claim 1.   An ink jet recording apparatus comprising the ink jet recording head according to claim 10. An ink jet comprising: a heating element side substrate provided with a heating element for ejecting ink droplets; and a cooling means for cooling the heating element side substrate by bringing a cooling liquid into contact with the heating element side substrate. A method for manufacturing a recording head chip, comprising:
Forming a groove in contact with the liquid on the back side of the wafer substrate on which the heating element side substrate is formed in an array;
Further, the cooling channel through which the liquid flows is formed by pasting the groove so as to cover the groove from the outside with a shielding film formed with a liquid inlet and a liquid outlet communicating with the groove. A method for manufacturing an inkjet recording head chip.   13. The method for manufacturing a chip for an ink jet recording head according to claim 12, wherein the shielding film is made of a resin, and the wafer substrate and the shielding film are bonded by anodic bonding. A method for manufacturing a chip for an ink jet recording head, comprising: a heating element side substrate provided with a heating element for discharging ink droplets; and a cooling means for air-cooling the heating element side substrate,
A method of manufacturing a chip for an ink jet recording head, wherein fins are formed by forming grooves on a back side of a wafer substrate on which the heating element side substrates are formed in an arrayed state.   The method for manufacturing a chip for an ink jet recording head according to claim 14, wherein the groove is formed by dry etching.   The inkjet recording according to claim 14 or 15, wherein a width of the fin is 500 μm or less, and a height of the fin is in a range of ½ to 8/11 of a thickness of the heating element side substrate. Manufacturing method of head chip.

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