JP6746329B2 - Method of manufacturing recording element substrate and liquid ejection head - Google Patents

Description

The present invention relates to a method for manufacturing a liquid discharge head of the recording element substrate used in the liquid discharge head.

A liquid ejecting apparatus that performs recording by ejecting a liquid onto a recording medium uses a liquid ejecting head having a pressure chamber communicating with an ejection port and a recording element that applies energy for ejecting the liquid in the pressure chamber. .. The recording element is also called an energy generating element. In the liquid ejection head, a large number of recording elements are generally arranged in rows. In recent years, in the liquid ejecting apparatus, it is desired to reduce the volume of each droplet ejected from the ejection port in order to improve the quality of recording. It has been known that when the volume of the liquid droplet is reduced, subtle variations such as the size of the ejection port affect ejection, which in turn affects recording quality. Therefore, in a liquid ejection head, it is common to form a recording element on a substrate made of, for example, silicon, which can ensure sufficient accuracy, and laminate a resin on the substrate to form an ejection port on this resin layer. There is.

In order to perform good recording, it is required that the plurality of recording elements forming the liquid ejection head have uniform physical properties. The recording element is, for example, a heating resistance element or a piezo element, but is generally formed by forming an element material on the above-described substrate, forming an element pattern with a resist, and then performing etching. Considering a group of recording elements arranged in a line, during etching, the etching liquid circulates better at both ends of the recording element group than at the central portion, so that a layer of element material is formed for each recording element, especially in the width direction of the substrate. It tends to be formed thin and its dimensions small. This phenomenon is also related to the diffusion of reaction products in the etching liquid, and when etching a shape in which a plurality of identical patterns are arranged, it is inevitably generated in the pattern arranged at the end. It is considered. Therefore, even if a plurality of recording elements are arranged in the center using a large recording element substrate, the one arranged at the end of the arranged recording elements is more likely to be etched than the one arranged in the central portion. It is believed to progress. When such a layer of the element material varies for each printing element, the ejection characteristics differ for each ejection port, resulting in deterioration of recording quality. In view of this, Japanese Patent Laid-Open No. 2004-242242 discloses that when the printing elements are heating resistors, pseudo printing elements (dummy printing elements) that do not contribute to liquid ejection are arranged at both ends of the row of printing elements. ing. In the one described in Patent Document 1, by providing the pseudo recording element, only the recording element formed in the region which is not affected by the variation in the circulation of the etching solution can be the recording element involved in the ejection. Uniform ejection characteristics can be realized.

In the liquid ejection head, when bubbles enter the pressure chamber, the pressure when ejecting the liquid from the ejection port changes unintentionally, the normal liquid ejection is stopped, and the normal recording operation becomes impossible. If the liquid ejection head is left without special protection such as a protective cap covering the ejection port, the viscosity of the liquid near the ejection port increases due to evaporation of water or solvent component from the ejection port, It may affect the ejection speed and the ejection direction. Patent Document 2 discloses that a circulation flow of a liquid passing through a pressure chamber is generated to avoid accumulation of bubbles inside the liquid ejection head and increase in viscosity of the liquid.

Japanese Patent Publication No. 7-29430 JP, 2010-188572, A

Even when a circulating flow of liquid passing through the pressure chamber is generated as described in Patent Document 2, evaporation of water and solvent components from the discharge port occurs, so that solute in the liquid is on the downstream side of the circulation. And the concentration of dispersoids increases. Therefore, when the liquid ejection head is used for a long period of time, the concentration of solutes and dispersoids in the liquid becomes high in the entire apparatus, and high recording quality may not be maintained. When the liquid passing through the pressure chamber is not circulated, the concentration rises only in the vicinity of the discharge port, so the concentration of solutes and dispersoids in the liquid is high in the entire device. This is an inherent problem in the liquid ejection head that produces a circulating flow. In particular, since the pseudo recording element is provided as described in Patent Document 1, if there is a discharge port that is not involved in discharge, evaporation of water or solvent from the discharge port is promoted, and the concentration of solute or dispersoid increases. It is accelerated and may have a bad influence on recording quality.
An object of the present invention is to provide a liquid ejection head that suppresses variations in ejection port size and various characteristics of recording elements to realize uniform ejection characteristics, and also suppresses density changes in ejected liquid to ensure high recording quality . A method of manufacturing a recording element substrate used and a liquid ejection head are provided.

A method of manufacturing a recording element substrate according to the present invention includes a substrate having a plurality of recording elements that generate energy for ejecting liquid on a first surface, and a plurality of substrates that are provided on the first surface side and eject liquid. A discharge port is formed, and a discharge port forming member forming a pressure chamber communicating with the substrate for each discharge port, and a second surface that is opposite to the first surface and the first surface. A recording element substrate having a supply port and a recovery port penetrating the substrate between itself and the plurality of pressure chambers to communicate with the plurality of pressure chambers, and the plurality of recording elements are arranged in a row on the first surface for recording. It is characterized in that it constitutes an element array. Further, at least one dummy recording element is provided at the end of the recording element array, and the remaining recording elements are recording elements related to ejection. For each pressure chamber, recording elements related to ejection are provided inside the pressure chamber. Is provided and a plurality of ejection ports are provided corresponding to only the recording elements related to ejection, or only the recording elements related to ejection and the recording elements related to the ejection for each recording element related to ejection. A method of manufacturing a recording element substrate used in a liquid ejection head having a pressure chamber provided therein, wherein a first resin layer is formed on a first surface of a substrate on which a recording element array is formed. And exposing a region including the position where the pressure chamber is formed, and after exposing the first resin layer, a second resin layer is formed on the first resin layer to form a region serving as a discharge port. It is characterized by including a step of exposing and a step of developing after the exposure of the second resin layer to form a pressure chamber and a discharge port .

The liquid ejection head of the present invention includes a substrate on which a plurality of recording elements that generate energy for ejecting liquid are provided on a first surface, and a plurality of ejection ports that are provided on the first surface side and eject liquid. A discharge port forming member that forms a pressure chamber that is formed between the substrate and each discharge port and communicates with the discharge port; and a first surface and a second surface that is opposite to the first surface. A recording element substrate having a supply port and a recovery port that penetrate through the substrate and communicate with a plurality of pressure chambers, and the plurality of recording elements are arranged in a row on the first surface to form a recording element row. At least one dummy recording element is provided at the end portion of the recording element array, and the remaining recording elements are recording elements related to ejection. For each pressure chamber, there is a recording element related to ejection inside the pressure chamber. The plurality of ejection ports are provided corresponding to only the recording elements related to ejection, and the pressure chamber-like space that does not communicate with the ejection port corresponds to the dummy recording element and is formed between the substrate and the ejection port. It is characterized by being formed of a forming member .

According to the present invention, it is possible to realize uniform ejection characteristics by suppressing variations in ejection port dimensions and various characteristics of recording elements, and also to suppress high density changes in ejected liquid to ensure high recording quality. A discharge head can be realized.

It is a figure which shows schematic structure of the liquid discharge apparatus of the 1st structural example. It is a figure explaining the 1st circulation form. It is a figure explaining the 2nd circulation form. It is a perspective view showing a configuration of a liquid ejection head. It is an exploded perspective view showing a liquid ejection head. It is a figure which shows the structure of the front surface and back surface of each flow path member. It is a perspective view which shows the connection relation of each flow path. It is sectional drawing which shows a flow path component and a discharge module. It is a figure explaining a discharge module. It is a figure which shows the structure of a recording element substrate. FIG. 3 is a partially cutaway perspective view showing a recording element substrate. FIG. 3 is a plan view showing adjacent recording element substrates. It is a figure which shows schematic structure of the liquid discharge apparatus of the 2nd structural example. It is a perspective view showing a configuration of a liquid ejection head. It is an exploded perspective view showing a liquid ejection head. It is a figure which shows the structure of each flow path member. It is a perspective view which shows the connection relation of each flow path. It is sectional drawing which shows a flow path component and a discharge module. It is a figure explaining a discharge module. It is a figure which shows the structure of a recording element substrate. It is a figure which shows the pressure chamber vicinity of a liquid discharge head. FIG. 6 is a partially enlarged view of a recording element substrate in a comparative example. FIG. 3 is a partially enlarged view of the recording element substrate according to the embodiment of the present invention. FIG. 6 is a partially enlarged view of a recording element substrate according to another embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing the manufacturing process of the recording element substrate.

An example of an embodiment of the present invention will be described below with reference to the drawings. However, the following description does not limit the scope of the present invention. As an example, in the following description, a heating element is used as a recording element that generates energy for ejecting liquid, and heat is used to generate bubbles in the liquid in the pressure chamber to eject the liquid from the ejection port The head will be described as an example. However, the liquid ejection head to which the present invention can be applied is not limited to the thermal type, and the present invention can be applied to a piezo type that uses a piezoelectric element and liquid ejection heads that employ various other types of liquid ejection. Can be applied.

Further, in the following description, a liquid ejection head used in a liquid ejection device that circulates a liquid such as a recording liquid between a tank and a liquid ejection head will be described. However, a liquid ejection device using the liquid ejection head according to the present invention will be described. It is not limited to this. A tank is provided on each of the upstream side and the downstream side without circulating the liquid, and the liquid is made to flow in the pressure chamber of the liquid discharge head by causing the liquid to flow from one tank to the other tank via the liquid discharge head. The present invention can also be applied to a liquid ejection device.

Further, in the following description, it is assumed that the liquid ejection head is configured as a so-called line type head having a length corresponding to the width of the recording medium. However, the present invention can be applied to a so-called serial type liquid ejection head in which recording on a recording medium is completed by scanning in the main scanning direction and the sub-scanning direction. As a serial type liquid ejection head, for example, there is a configuration in which one recording element substrate for black recording liquid and one recording element substrate for color recording liquid are mounted, but the invention is not limited to this. The serial type liquid discharge head is a line head having several recording element substrates arranged so that the discharge ports overlap in the discharge port array direction, and a short line head shorter than the width of the recording medium is created. The medium may be scanned.

(Description of Liquid Ejection Device of First Configuration Example)
First, as an example of the liquid ejection apparatus according to the present invention, an inkjet recording apparatus 1000 (hereinafter, also referred to as a recording apparatus) that ejects a recording liquid as a liquid from an ejection port to perform recording on a recording medium will be described. FIG. 1 shows a schematic configuration of a recording apparatus 1000 which is a liquid ejection apparatus of the first configuration example. The recording apparatus 1000 includes a transport unit 1 that transports the recording medium 2, and a line-type liquid ejection head 3 that is disposed substantially orthogonal to the transport direction of the recording medium 2. This is a line-type recording apparatus that performs continuous recording in one pass while conveying continuously or intermittently. The recording medium 2 is, for example, cut paper, but may be continuous roll paper or the like other than cut paper. The liquid discharge head 3 is capable of full-color recording with a recording liquid of each color of cyan (C), magenta (M), yellow (Y), and black (K) (hereinafter, these colors are also collectively referred to as CMYK). It is something. As will be described later, the liquid ejection head 3 is fluidly connected to a liquid supply unit that is a supply path for supplying the liquid to the liquid ejection head 3, a main tank, and a buffer tank (see FIG. 2 ). As shown in FIG. 2 described later, the liquid discharge head 3 is roughly composed of a liquid supply unit 220, a negative pressure control unit 230, and a liquid discharge unit 300. The liquid ejection unit 300 is provided with a plurality of recording element substrates 10, a common supply channel 211, and a common recovery channel 212, and each recording element substrate 10 is provided with a plurality of recording elements. In the liquid ejection head 300, a recording liquid is supplied to each recording element substrate 10 from a common supply path 211 as shown by an arrow in the drawing, and the recording liquid is recovered through a common recovery channel 212. There is. Further, the liquid ejection head 3 is electrically connected to an electric control unit that transmits electric power and an ejection control signal to the liquid ejection head 3. Details of the liquid path and the electric signal path in the liquid ejection head 3 will be described later.

(Explanation of the first circulation mode)
FIG. 2 shows a first circulation mode which is one mode of the circulation path configuration applied to the liquid ejection apparatus according to the present invention. In the first circulation mode, the liquid discharge head 3 is fluidly connected to the first circulation pump 1001 on the high pressure side, the first circulation pump 1002 on the low pressure side, the buffer tank 1003, and the like. Note that, in FIG. 2, for simplification of description, only a path through which one color of the CMYK color recording liquids flows is shown, but in reality, the circulation paths for four colors are the liquid ejection heads 3. And provided in the recording apparatus main body. The buffer tank 1003, which is connected to the main tank 1006 and serves as a sub tank, functions as a storage unit that stores the recording liquid, has an atmosphere communication port (not shown) that communicates the inside and the outside of the tank, and records. Air bubbles in the liquid can be discharged to the outside. The buffer tank 1003 is also connected to the replenishment pump 1005. The replenishment pump 1005 is consumed when the liquid is discharged from the liquid discharge head 3 by discharging (discharging) the recording liquid from the discharge port of the liquid discharge head such as recording by discharging the recording liquid and suction recovery. The recording liquid component is transferred from the main tank 1006 to the buffer tank 1003.

The two first circulation pumps 1001 and 1002 have a role of drawing the liquid from the liquid connection portion 111 of the liquid ejection head 3 and flowing it to the buffer tank 1003. As the first circulation pumps 1001 and 1002, it is preferable to use positive displacement pumps having a quantitative liquid feeding capacity. Specific examples thereof include a tube pump, a gear pump, a diaphragm pump, and a syringe pump. For example, a general constant flow valve or a relief valve may be used at a pump outlet to ensure a constant flow rate. be able to. When the liquid ejection head 300 is driven, the recording liquid flows at a certain constant flow rate in the common supply passage 211 and the common recovery passage 212 by the first circulation pump 1001 on the high pressure side and the first circulation pump 1002 on the low pressure side, respectively. It is preferable that the flow rate is set to such a level that the temperature difference between the recording element substrates 10 in the liquid ejection head 3 does not affect the recording quality on the recording medium 2. However, if an excessively large flow rate is set, the negative pressure difference in each recording element substrate 10 becomes too large due to the influence of the pressure loss of the flow path in the liquid ejection unit 300, resulting in uneven density in the recorded image. Therefore, it is preferable to set the flow rate while considering the temperature difference and the negative pressure difference between the respective recording element substrates 10. Of the paths through which the recording liquid circulates, the path that includes the first circulation pump 1001 on the high pressure side constitutes the first circulation system in this liquid ejection device, and the path that includes the first circulation pump 1002 on the low pressure side The path constitutes a second circulation system in this liquid ejection device.

A second circulation pump 1004 is provided in a path for supplying the recording liquid from the buffer tank 1003 toward the liquid ejection head 3. The negative pressure control unit 230 is provided in the path between the second circulation pump 1004 and the liquid ejection unit 300. Even when the flow rate of the circulation system changes due to the difference in duty when performing the recording, the negative pressure control unit 230 sets the pressure on the downstream side (that is, the liquid ejection unit 300 side) of the negative pressure control unit 230 to a preset constant pressure. It has the function of maintaining. The negative pressure control unit 230 includes two pressure adjusting mechanisms in which different control pressures are set. As these two pressure adjusting mechanisms, any mechanism may be used as long as it can control the pressure downstream of itself with a fluctuation within a certain range around a desired set pressure. As an example, a device having a mechanism similar to that of a so-called decompression regulator can be adopted. When a decompression regulator is used as the pressure adjusting mechanism, it is preferable that the second circulation pump 1004 pressurize the upstream side of the negative pressure control unit 230 via the liquid supply unit 200, as shown in FIG. By doing so, the influence of the head pressure of the buffer tank 1003 on the liquid ejection head 3 can be suppressed, so that the flexibility of the layout of the buffer tank 1003 in the recording apparatus 1000 can be increased. As the second circulation pump 1004, a pump having a head pressure of a certain pressure or higher within the range of the circulation flow rate of the recording liquid used when the liquid ejection head 3 is driven may be used, and a turbo pump, a positive displacement pump, or the like may be used. Can be used. Specifically, a diaphragm pump or the like can be used. Further, instead of the second circulation pump 1004, for example, a head tank arranged with a certain head difference with respect to the negative pressure control unit 230 can be provided.

Of the two pressure adjustment mechanisms in the negative pressure control unit 230, the pressure adjustment mechanism in which a relatively high pressure is set (indicated by H in FIG. 2) is the liquid ejection unit 300 via the liquid supply unit 220. Is connected to the common supply path 211 inside. Similarly, the pressure adjusting mechanism (indicated by L in FIG. 2) in which a relatively low pressure is set is connected to the common recovery passage 212 in the liquid ejection unit 300 via the inside of the liquid supply unit 220. In addition to the common supply path 211 and the common recovery flow path 212, the liquid ejection unit 300 is provided with an individual supply flow path 213 and an individual recovery flow path 214 that communicate with each of the recording element substrates 10. The individual supply channel 213 and the individual recovery channel 214 provided for each printing element substrate are collectively referred to as an individual channel. The individual flow paths are provided so as to branch from the common supply flow path 211 and join the common recovery flow path 212 and communicate with them. Therefore, a flow (white arrow in FIG. 2) in which a part of the liquid such as the recording liquid flows from the common supply channel 211 through the internal channel of the recording element substrate 10 to the common recovery channel 212. This is because the high pressure side pressure adjusting mechanism H is connected to the common supply channel 211 and the low pressure side pressure adjusting mechanism L is connected to the common recovery channel 212, so that the common supply channel 211 and the common recovery channel are connected. This is because a differential pressure is generated between the paths 213.

In this way, in the liquid ejection unit 300, while flowing the liquid so as to pass through the common supply flow passage 211 and the common recovery flow passage 212, a part of the liquid passes through the inside of each recording element substrate 10. Flow occurs. Therefore, the heat generated in each recording element substrate 10 can be discharged to the outside of the recording element substrate 10 by the flow of the common supply channel 211 and the common recovery channel 212. During recording by the liquid ejection head 3, a flow of the recording liquid can be generated even in an ejection port or a pressure chamber in which recording is not performed, and therefore, due to evaporation of the solvent component of the recording liquid at that portion. It is possible to prevent the viscosity of the recording liquid from increasing. Further, the thickened recording liquid and the foreign matter in the recording liquid can be discharged to the common recovery channel 212. Therefore, it is possible to perform high-speed and high-quality recording by using the liquid ejection head 3 described above.

(Explanation of the second circulation mode)
FIG. 3 shows a second circulation mode which is a circulation mode different from the above-described first circulation mode in the circulation path configuration applied to the liquid ejection apparatus according to the present invention. The main difference between the second circulation mode and the first circulation mode is that each of the two pressure adjusting mechanisms constituting the negative pressure control unit 230 controls the pressure on the upstream side of the negative pressure control unit 230. This is a mechanism for controlling the fluctuation within a certain range around the desired set pressure. Such a pressure adjusting mechanism can be configured as a mechanical component having the same operation as a so-called back pressure regulator. Further, the second circulation pump 1004 acts as a negative pressure source that reduces the pressure on the downstream side of the negative pressure control unit 230, and the high-pressure side and low-pressure side first circulation pumps 1001 and 1002 are arranged on the upstream side of the liquid ejection head 3. ing. Along with this, the negative pressure control unit 230 is arranged on the downstream side of the liquid ejection head 3.

In the second circulation mode, the negative pressure control unit 230 presets the pressure fluctuation on the upstream side thereof even if there is a fluctuation in the flow rate caused by a change in the printing duty when printing is performed by the liquid ejection head 3. It operates to stabilize within a certain range around the pressure. Here, the upstream side of the negative pressure control unit 230 is the liquid ejection unit 300 side. As shown in FIG. 3, it is preferable that the second circulation pump 1004 pressurize the downstream side of the negative pressure control unit 230 via the liquid supply unit 220. In this way, the influence of the head pressure of the buffer tank 1003 on the liquid ejection head 3 can be suppressed, so that the selection range of the layout of the buffer tank 1003 in the recording apparatus 1000 can be widened. Instead of the second circulation pump 1004, for example, a head tank arranged with a predetermined head difference with respect to the negative pressure control unit 230 may be provided.

As in the case of the first circulation mode, as shown in FIG. 3, the negative pressure control unit 230 includes two pressure adjusting mechanisms in which control pressures different from each other are set. The high-pressure setting side (denoted as H in FIG. 3) and the low-pressure setting side pressure adjustment mechanism (denoted as L in FIG. 3) respectively pass through the inside of the liquid supply unit 220 and the common supply channel in the liquid ejection unit 300. 211 and the common recovery channel 212. By making the pressure of the common supply channel 211 relatively higher than the pressure of the common recovery channel 212 by these two pressure adjusting mechanisms, the individual channels and the internal channels of each recording element substrate 10 from the common supply channel 211. A flow of the recording liquid flowing to the common recovery channel 212 via the is generated. The flow of the recording liquid is shown by a white arrow in FIG. As described above, in the second circulation mode, the flow state of the recording liquid similar to that in the first circulation mode is obtained in the liquid ejection unit 300, but there are two advantages different from the case of the first circulation path.

The first advantage is that, in the second circulation mode, the negative pressure control unit 230 is arranged on the downstream side of the liquid ejection head 3, so that dust or foreign matter generated from the negative pressure control unit 230 flows into the liquid ejection head 3. There is little concern about it.

The second advantage is that in the second circulation mode, the maximum value of the necessary flow rate supplied from the buffer tank 1003 to the liquid ejection head 3 can be smaller than in the first circulation mode. The reason is as follows. Let A be the total of the flow rates in the common supply flow path 211 and the common recovery flow path 212 when circulating during the recording standby. The value of A is defined as the minimum flow rate required to bring the temperature difference in the liquid ejection unit 300 into a desired range when the temperature of the liquid ejection head 3 is adjusted during recording standby. Further, the discharge flow rate when the recording liquid is discharged from all the discharge ports of the liquid discharge unit 300 (at the time of full discharge) is defined as F. Then, in the case of the first circulation mode shown in FIG. 2 (FIG. 2 ), the set flow rates of the first circulation pump (high pressure side) 1001 and the first circulation pump (low pressure side) 1002 become A, and therefore, at the time of full discharge The maximum value of the required liquid supply amount to the liquid ejection head 3 is A+F. On the other hand, in the case of the second circulation mode shown in FIG. 3, the liquid supply amount to the liquid ejection head 3 required during the recording standby is the flow rate A. The flow rate F is the amount of supply to the liquid ejection head 3 that is required at the time of full ejection. Then, in the case of the second circulation mode, the total value of the set flow rates of the first circulation pumps 1001 and 1002 on the high-pressure side and the low-pressure side, that is, the maximum value of the required supply flow rate is the larger value of A or F. Therefore, as long as the liquid discharge unit 300 having the same configuration is used, the maximum value (A or F) of the required supply amount in the second circulation mode is greater than the maximum value (A+F) of the required supply flow rate in the first circulation mode. Will definitely be smaller. Therefore, in the case of the second circulation mode, the degree of freedom of the applicable circulation pump is increased, and for example, a low-cost circulation pump having a simple configuration is used, or a load of a cooler (not shown) installed in the main body side path is used. Can be reduced, and the cost of the recording apparatus main body can be reduced. This advantage increases as the line type head has a relatively large value of A or F, and the line type head is more advantageous in the longitudinal direction head.

However, on the other hand, there is also an advantage that the first circulation mode is more advantageous than the second circulation mode. In the second circulation mode, since the flow rate of the liquid flowing through the liquid ejection unit 300 is maximum during the recording standby, the higher the negative pressure is applied to each ejection port, the lower the printing duty of the image. For this reason, especially when the head width is reduced by reducing the channel widths of the common supply channel 211 and the common recovery channel 212, a high negative pressure is applied to the ejection port in a low duty image in which unevenness is easily visible. The impact of satellite drops can be significant. Here, the channel width of the common supply channel 211 and the common recovery channel 212 is the length in the direction orthogonal to the flow direction of the liquid, and the head width is the length in the lateral direction of the liquid ejection head 3. Is. On the other hand, in the case of the first circulation mode, the high negative pressure is applied to the ejection port at the time of high-duty image formation. Therefore, even if satellite droplets are generated, it is difficult to see in the recorded image, and Has the advantage that the effect of is small. In selecting these two circulation forms, a preferable one may be selected in view of the specifications of the liquid ejection head 3 and the recording apparatus main body (ejection flow rate F, minimum circulation flow rate A, and flow path resistance in the liquid ejection head 3). ..

(Description of liquid ejection head configuration)
Next, the configuration of the liquid ejection head 3 will be described with reference to FIG. 4A is a perspective view of the liquid ejection head 3 as seen from the side where the ejection openings are formed, and FIG. 4B is a perspective view as seen from the opposite direction to FIG. The liquid ejection head 3 has 15 recording element substrates 10 arranged in a line (inline) capable of ejecting recording liquids of four colors of cyan (C), magenta (M), yellow (Y) and black (K). Is a line-type liquid discharge head. As shown in FIG. 4A, the liquid ejection head 3 includes fifteen recording element substrates 10, a flexible wiring substrate 40, and an electric wiring substrate 90. A signal input terminal 91 and a power supply terminal 92 are provided on the electric wiring board 90, and the signal input terminal 91 and the power supply terminal 92 are provided on each recording element board 10 via the electric wiring board 90 and the flexible wiring board 40. It is electrically connected. The signal input terminal 91 and the power supply terminal 92 are electrically connected to the control circuit of the printing apparatus 1000, and respectively supply an ejection drive signal and electric power required for ejection to the printing element substrate 10. The number of the signal input terminals 91 and the power supply terminals 92 can be reduced as compared with the number of the recording element boards 10 by collecting the wirings by the electric circuits in the electric wiring board 90. As a result, it is possible to reduce the number of electrical connection portions that need to be removed when the liquid ejection head 3 is assembled to the recording apparatus 1000 or when the liquid ejection head is replaced. As shown in FIG. 4B, the liquid connection portions 111 provided at both ends of the liquid ejection head 3 are connected to the liquid supply system of the recording apparatus 1000 as shown in FIG. 2 or 3, for example. As a result, the recording liquid of each color of CMYK is supplied from the supply system of the recording apparatus 1000 to the liquid ejection head 3, and the recording liquid that has passed through the liquid ejection head 3 is collected by the supply system of the recording apparatus 1000. There is. As described above, the recording liquid of each color can be circulated through the path of the recording apparatus 1000 and the path of the liquid ejection head 3.

FIG. 5 shows each component or unit forming the liquid ejection head 3 divided by its function. The liquid ejection head 3 includes a housing 80, and the liquid ejection unit 300, the liquid supply unit 220, and the electric wiring board 90 are attached to the housing 80. The liquid supply unit 220 is provided with a liquid connection portion 111 (see FIGS. 2 to 4). Inside the liquid supply unit 220, in order to remove foreign matter in the supplied recording liquid, a filter 221 for each color (see FIGS. 2 and 3) that communicates with each opening of the liquid connection portion 111 is provided. In the illustrated example, two liquid supply units 220 and two negative pressure control units 230 are provided for one liquid ejection head. Each of the two liquid supply units 220 is provided with a filter 221 for two colors. The recording liquid that has passed through the filter 221 is supplied to the negative pressure control unit 230 arranged on the supply unit 220 corresponding to each color. The negative pressure control unit 230 has a pressure adjusting mechanism, and the inside of the supply system of the recording apparatus 1000 (the liquid ejecting head) generated by the fluctuation of the flow rate of the liquid due to the action of the valve and the spring member provided inside the pressure adjusting mechanism. The change in pressure loss of the supply system on the upstream side of 3) can be significantly attenuated. As a result, the negative pressure control unit 230 can stabilize the negative pressure change on the downstream side (the liquid ejection unit 300 side) of the pressure control unit within a certain fixed range. As described above, the negative pressure control unit 230 is provided with two pressure adjusting mechanisms for each color, and the control pressures of the two pressure adjusting mechanisms for each color are set to different values. The pressure adjusting mechanism on the high pressure side communicates with the common supply passage 211 in the liquid discharge unit 300, and the pressure adjusting mechanism on the low pressure side communicates with the common recovery passage 212.

The housing 80 includes a liquid ejection unit support 81 and an electric wiring board support 82, supports the liquid ejection unit 300 and the electric wiring board 90, and secures the rigidity of the liquid ejection head 3. The electric wiring board supporting portion 82 is for supporting the electric wiring board 90, and is fixed to the liquid ejection unit supporting portion 81 by screwing. The liquid ejection unit support portion 81 has a role of correcting warpage and deformation of the liquid ejection unit 300 and ensuring relative positional accuracy of the plurality of recording element substrates 10, and thereby suppresses streaks and unevenness in the recorded matter. Therefore, the liquid discharge unit support portion 81 preferably has sufficient rigidity, and as the material thereof, a metal material such as stainless steel (SUS) or aluminum, or a ceramic such as alumina is suitable. At both ends of the liquid ejection unit support portion 81 in the longitudinal direction, openings 83 and 84 into which the joint rubber 100 is inserted are provided. A liquid such as a recording liquid supplied from the liquid supply unit 220 is guided to a third flow path member 70, which will be described later, which constitutes the liquid ejection unit 300 via the joint rubber 100.

The liquid ejection unit 300 includes a plurality of ejection modules 200 and a flow path forming member 210, and a cover member 130 is attached to the surface of the liquid ejection unit 300 on the recording medium side. As shown in FIG. 5, the cover member 130 is a member having a frame-like surface provided with a long opening 131, and the recording element substrate 10 and the sealing material 110 (which are included in the ejection module 200 from the opening 131. (See FIG. 9) is exposed. The frame portion around the opening 131 has a function as a contact surface of a cap member that caps the surface of the liquid ejection head 3 on which the ejection port is formed during recording standby. Therefore, a closed space is formed at the time of capping by applying an adhesive, a sealing material, a filling material, or the like along the periphery of the opening 131 to fill the irregularities or gaps on the ejection port formation surface of the liquid ejection unit 300. It is preferable to do so.

Next, the configuration of the flow path forming member 210 included in the liquid ejection unit 300 will be described. The flow path forming member 210 is for distributing the liquid such as the recording liquid supplied from the liquid supply unit 220 to each ejection module 200, and for returning the liquid refluxed from the ejection module 200 to the liquid supply unit 220. is there. As shown in FIG. 5, the flow path forming member 210 is formed by stacking the first flow path member 50, the second flow path member 60, and the third flow path member 70 in this order, and the liquid discharge unit support portion 81. It is fixed with screws. As a result, warpage and deformation of the flow path forming member 210 are suppressed.

FIGS. 6A to 6F show the front and back surfaces of the first to third flow path members 50, 60, 70. FIG. 6A shows the surface of the first flow path member 50 on the side on which the discharge module 200 is mounted, while FIG. 6F shows the liquid discharge unit of the third flow path member 70. The surface on the side in contact with the support portion 81 is shown. FIG. 6B shows a contact surface of the first flow path member 50 with the second flow path member 60. Correspondingly, FIG. 6C shows the contact surface of the second flow path member 60. The contact surface with the one flow path member 50 is shown. Similarly, FIG. 6D shows the contact surface of the second flow path member 60 with the third flow path member 70, and FIG. 6E shows the second flow path of the third flow path member 70. The contact surface with the member 60 is shown. A common flow channel groove formed in each of the flow channel members 60, 70 by joining the second flow channel member 60 and the third flow channel member 70 at the surfaces shown in (d) and (e) of FIG. 62 and 71 form eight common channels extending in the longitudinal direction of these channel members 60 and 70. As a result, a set of the common supply flow channel 211 and the common recovery flow channel 212 for each color of CMYK is formed in the flow channel constituent member 210 (see FIG. 7). The communication port 72 of the third flow path member 70 communicates with each hole of the joint rubber 100 and is in fluid communication with the liquid supply unit 220. A plurality of communication ports 61 are formed on the bottom surface of the common flow channel 62 of the second flow channel member 60 and communicate with one end of the individual flow channel 52 of the first flow channel member 50. A communication port 51 is formed at the other end of the individual flow channel groove 52 of the first flow channel member 50, and is in fluid communication with the plurality of discharge modules 200 via the communication port 51. The individual flow channel grooves 52 allow the flow channels to be concentrated on the center side of the first flow channel member 50 in the lateral direction. In the following description, reference numerals 211a to 211d are used instead of reference numeral 211 when the common supply channels 211 are shown separately for each color of the recording liquid, and reference numerals 211a to 211d are used when the common recovery path 212 is shown separately for each color. Reference numerals 212a to 212d are used instead of 212. Similarly, reference numerals 213a to 213d are used in place of the reference numeral 213 when the individual supply channels 213 are shown separately for each color of the recording liquid, and reference numerals 214 are used instead when the common recovery path 214 is shown for each color. Reference numerals 214a to 214d are used for.

It is preferable that the first to third flow path members 50, 60, 70 forming the flow path forming member 210 are made of a material having a low coefficient of linear expansion while having a corrosion resistance against a liquid such as a recording liquid. As the material, for example, a composite material (resin material) in which alumina, LCP (liquid crystal polymer), PPS (polyphenyl sulfide) or PSF (polysulfone) is used as a base material and an inorganic filler such as silica fine particles or fibers is added is preferable. Can be used. As a method of forming the flow path forming member 210, three flow path members 50, 60, 70 may be laminated and adhered to each other. If a resin composite resin material is selected as the material, a joining method by welding is used. May be used.

Next, the connection relationship of each flow path in the flow path forming member 210 will be described with reference to FIG. 7. In FIG. 7, the discharge module 200 of the first flow path member 50 is mounted on the flow path inside the flow path constituent member 210 formed by joining the first to third flow path members 50, 60, 70. FIG. 3 is a perspective view of a part of the surface on which the surface is enlarged. The area surrounded by the alternate long and short dash line in FIG. 7 corresponds to the arrangement position of the recording element substrate 10. The flow channel forming member 210 is provided with common supply flow channels 211a to 211d and common recovery flow channels 212a to 212d that extend in the longitudinal direction of the liquid ejection head 3 for each color. A plurality of individual supply channels 213a to 213d formed by the individual channel grooves 52 are connected to the common supply channels 211a to 211d of each color via the communication ports 61, respectively. A plurality of individual recovery channels 214 a to 214 d formed by the individual channel grooves 52 are connected to the common recovery channels 212 a to 212 d of each color via the communication ports 61. With such a flow path configuration, the recording liquid is collected from each common supply flow path 211 through the individual supply flow path 213 to the recording element substrate 10 provided corresponding to the central portion of the flow path forming member 210. can do. Further, the recording liquid can be collected from the recording element substrate 10 to each common recovery channel 212 via the individual recovery channel 214.

FIG. 8 shows a cross-sectional structure of the flow path forming member 210 and the discharge module 200 taken along the line EE of FIG. 7. As shown in the drawing, the individual recovery flow paths 214 a and 214 c are in communication with the discharge module 200 via the communication port 51. Although FIG. 8 illustrates only the individual recovery flow paths 214a and 214c, in another cross section, the individual supply flow path 213 and the discharge module 200 communicate with each other as shown in FIG. In order to supply the recording liquid from the first flow path member 50 to the recording element 15 (see FIG. 10) provided in the recording element substrate 10, the supporting member 30 and the recording element substrate 10 included in each ejection module 200. Is formed. Further, the support member 30 and the recording element substrate 10 are also formed with channels for collecting (refluxing) part or all of the liquid supplied to the recording element 15 into the first channel member 50. The common supply channel 211 of each color is connected to the high-pressure side pressure adjusting mechanism of the negative pressure control unit 230 of the corresponding color via the liquid supply unit 220. Similarly, the common recovery channel 212 is connected to the pressure adjusting mechanism on the low pressure side of the negative pressure control unit 230 of the corresponding color via the liquid supply unit 220. By these pressure adjusting mechanisms in the negative pressure control unit 230, a pressure difference (pressure difference) is generated between the common supply flow passage 211 and the common recovery flow passage 212. Therefore, in the liquid ejection head 3 in which the respective flow paths are connected as shown in FIGS. 7 and 8, the common supply flow path 211→the individual supply flow path 213→the recording element substrate 10→the individual recovery flow for each color. A flow is sequentially generated from the passage 214 to the common recovery passage 212.

(Explanation of discharge module)
Next, the discharge module 200 will be described. 9A is a perspective view of the discharge module 200, and FIG. 9B is an exploded view thereof. As a method of manufacturing the ejection module 200, first, the recording element substrate 10 and the flexible wiring substrate 40 are bonded to the support member 30 provided with the liquid communication port 31 in advance. After that, the terminals 16 on the recording element substrate 10 and the terminals 41 on the flexible wiring substrate 40 are electrically connected by wire bonding, and then the wire bonding portion (electrical connection portion) is covered with the sealing material 110 and sealed. Stop. The terminal 42 on the side opposite to the recording element substrate 10 of the flexible wiring board 40 is electrically connected to the connection terminal 93 (see FIG. 5) of the electric wiring board 90. Since the support member 30 is a support member that supports the recording element substrate 10 and is a flow path communication member that fluidly connects the recording element substrate 10 and the flow path component member 210, it has high flatness and sufficient flatness. What can be bonded to the recording element substrate with high reliability is preferable. As a material of the support member 30, for example, alumina or a resin material is preferable.

(Description of structure of recording element substrate)
Next, the configuration of the recording element substrate 10 will be described. 10A is a plan view of the surface of the recording element substrate 10 on the side where the ejection ports 13 are formed, and FIG. 10B is an enlarged view of the portion indicated by A in FIG. FIG. 10C is a plan view of the side corresponding to the back surface of FIG. As shown in FIG. 10A, the recording element substrate 10 has an ejection port forming member 12 in which a plurality of ejection ports 13 are formed in rows. The ejection port forming member 12 is formed with four ejection port arrays corresponding to the four colors of CMYK, which are the colors of the recording liquid. Note that, hereinafter, the direction in which the ejection port array in which the plurality of ejection ports 13 are arranged extends is referred to as the “ejection port array direction”. In the ejection port forming member 12, elongated recesses 25 (see FIG. 11) extending in the ejection port array direction are formed on the surface of the substrate 11 side described later in order to form a plurality of pressure chambers 23 described below. The discharge ports 13 are provided in the recess 25. As shown in FIG. 10B, a recording element 15 which is a heating element for bubbling the liquid by thermal energy is arranged at a position corresponding to each ejection port 13. Since the recording elements 15 are also arranged in rows, this row is called a "recording element row". The partition wall 22, which is a part of the ejection port forming member 12, defines a pressure chamber 23 having the recording element 15 therein. The recording element 15 is electrically connected to the terminal 16 shown in FIG. 10A by an electric wiring (not shown) provided on the recording element substrate 10. The recording element 15 generates heat based on a pulse signal input from the control circuit of the recording apparatus 1000 via the electric wiring board 90 (FIG. 5) and the flexible wiring board 40 (FIG. 9), and the liquid in the pressure chamber 23 is boiled. Then, the liquid is discharged from the discharge port 13 by the bubbling force caused by the boiling. As shown in FIG. 10B, a liquid supply path 18 extends on one side and a liquid recovery path 19 extends on the other side along each ejection port array. The liquid supply path 18 and the liquid recovery path 19 are flow paths provided in the recording element substrate 10 and extending in the ejection port array direction, and communicate with the ejection port 13 via the supply port 17a and the recovery port 17b, respectively. ..

As shown in FIGS. 10C and 11, a sheet-shaped lid member 20 is laminated on the back surface of the surface of the recording element substrate 10 on which the ejection ports 13 are formed, and the lid member 20 will be described later. A plurality of openings 21 communicating with the liquid supply path 18 and the liquid recovery path 19 are provided. In the example shown here, the lid member 20 is provided with three openings 21 for one liquid supply path 18 and two openings 21 for one liquid recovery path 19. As shown in FIG. 10B, each opening 21 of the lid member 20 communicates with the plurality of communication ports 51 shown in FIG. 6A. As shown in FIG. 11, the lid member 20 has a function as a lid that forms part of the walls of the liquid supply passage 18 and the liquid recovery passage 19 formed in the substrate 11 of the recording element substrate 10. The lid member 20 is preferably made of a material having sufficient corrosion resistance to a liquid such as a recording liquid, and from the viewpoint of preventing color mixing, the opening shape and the opening position of the opening 21 are highly accurate. Is required. Therefore, it is preferable to use a photosensitive resin material or a silicon plate as the material of the lid member 20, and to provide the opening 21 by a photolithography process. As described above, the lid member 20 converts the pitch of the flow path by the opening 21, and it is desirable that the lid member 20 has a small thickness in consideration of the pressure loss, and it is desirable that the lid member 20 be formed of a film-shaped member.

Next, the flow of liquid in the recording element substrate 10 will be described. FIG. 11 shows a cross section of the recording element substrate 10 and the lid member 20 taken along the line BB in FIG. In the recording element substrate 10, a substrate 11 formed of a silicon (Si) substrate and an ejection port forming member 12 formed of a photosensitive resin are laminated. Assuming that the side on which the ejection port forming member 12 is laminated is the first surface of the substrate 11, the recording element 15 is formed on the first surface side of the substrate 11 (see FIG. 10), and the first element of the substrate 11 is formed. The lid member 20 is joined to the second surface opposite to the surface. On the second surface side of the substrate 11, grooves that form the liquid supply passage 18 and the liquid recovery passage 19 that extend along the ejection port array are formed. The supply port 17a and the recovery port 17b, which communicate with the liquid supply channel 18 and the liquid recovery channel 19, respectively, are provided in the substrate 11 as through holes that communicate the first surface and the second surface of the substrate 11, respectively. ing. Although the individual supply flow paths 213 and the individual recovery flow paths 214 are formed in the first flow path member 50, the individual supply flow paths 213 connect the liquid supply path 18 and the common supply flow path 211 to one another The path 214 connects the liquid recovery path 19 and the common recovery path 212. Therefore, the liquid supply passage 18 and the liquid recovery passage 19 formed by the substrate 11 and the lid member 20 should be connected to the common supply passage 211 and the common recovery passage 212, respectively, in the passage forming member 210. Becomes Due to the above-described differential pressure between the common supply flow path 211 and the common recovery flow path 212, a differential pressure is also generated between the liquid supply path 18 and the liquid recovery path 19. At the ejection ports that are not ejecting while recording is performed by ejecting the liquid from the plurality of ejection ports 13 of the liquid ejection head 3, the liquid in the liquid supply path 18 is supplied with the liquid through the supply ports 17a due to this differential pressure. →pressure chamber 23→flows to the liquid recovery path 19 via the recovery port 17b. This flow is indicated by arrow C in FIG. By this flow, in the discharge port 13 and the pressure chamber 23 in which recording is stopped, the thickened recording liquid generated by the vaporization of the solvent from the discharge port 13 and bubbles/foreign substances are collected in the liquid recovery path 19. You can Further, it is possible to suppress the viscosity increase of the recording liquid in the ejection port 13 and the pressure chamber 23. The liquid such as the recording liquid recovered in the liquid recovery passageway 19 passes through the opening 21 of the lid member 20 and the liquid communication port 31 of the support member 30 (see FIG. 9B), and the communication port 51 in the flow path forming member 210. , The individual recovery channel 214, and the common recovery channel 212 in this order. The collected liquid is finally collected in the supply path of the recording apparatus 1000.

After all, the liquid such as the recording liquid supplied from the main body of the recording apparatus 1000 to the liquid ejection head 3 flows, is supplied and collected in the following order. The liquid first flows into the liquid ejection head 3 from the liquid connection portion 111 of the liquid supply unit 220. Then, the liquid is the joint rubber 100, the communication passage 72 and the common flow passage groove 71 provided in the third flow passage member 70, the common flow passage groove 62 and the communication passage 61 provided in the second flow passage member 60, The individual flow channel groove 52 and the communication port 51 provided in one flow channel member are supplied in this order. After that, the liquid is supplied to the pressure chamber 23 through the liquid communication port 31 provided in the support member 30, the opening 21 provided in the lid member 20, the liquid supply path 18 provided in the substrate 11, and the supply port 17a in this order. To be done. Of the liquid supplied to the pressure chamber 23, the liquid not discharged from the discharge port 13 includes a recovery port 17b and a liquid recovery path 19 provided in the substrate 11, an opening 21 provided in the lid member 20, and a support member 30. Flow through the liquid communication port 31 provided in the. Then, the liquid flows to the communication port 51 and the individual flow channel 52 provided in the first flow channel member, the communication port 61 and the common flow channel 62 provided in the second flow channel member, and the third flow channel member 70. It flows through the provided common channel groove 71, the communication port 72, and the joint rubber 100 in order. Then, the liquid flows from the liquid connection portion 111 provided in the liquid supply unit 220 to the outside of the liquid ejection head 3. When the first circulation mode shown in FIG. 2 is adopted, the liquid flowing in from the liquid connecting portion 111 is supplied to the joint rubber 100 after passing through the negative pressure control unit 230. On the other hand, in the case of adopting the second circulation mode shown in FIG. 3, the liquid recovered from the pressure chamber 23 passes through the joint rubber 100 and then flows from the liquid connecting portion 111 via the negative pressure control unit 230. It flows to the outside of the ejection head 3.

Note that not all the liquid that has flowed in from one end of the common supply channel 211 of the liquid ejection unit 300 is supplied to the pressure chamber 23 via the individual supply channel 213a. As shown in FIGS. 2 and 3, some liquid flows from the other end of the common supply channel 211 to the liquid supply unit 220 without flowing into the individual supply channel 213a. By providing the flow path without passing through the recording element substrate 10 as described above, even when the recording element substrate 10 having a fine flow path with a large flow resistance is provided, the backflow of the circulation flow of the liquid is suppressed. can do. In this way, in the liquid ejection head 3, it is possible to suppress the increase in the viscosity of the liquid in the pressure chamber and the vicinity of the ejection port, so that it is possible to suppress ejection deviation and ejection failure, and as a result, it is possible to perform high-quality recording.

(Explanation of positional relationship between printing element substrates)
As described above, the liquid ejection head 3 includes the plurality of ejection modules 200. FIG. 12 is a partially enlarged view of the adjacent portion of the recording element substrate 10 in two adjacent ejection modules 200. As shown in FIG. 10, here, a recording element substrate 10 having a substantially parallelogram shape is used. As shown in FIG. 12, the ejection port arrays 14a to 14d in which the ejection ports 13 are arranged on each recording element substrate 10 are arranged so as to be inclined at a constant angle with respect to the transport direction L of the recording medium. As a result, at least one ejection port of the ejection port arrays in the adjacent portions of the recording element substrates 10 overlaps in the transport direction L of the recording medium. In the case shown in FIG. 12, the two ejection ports 13 on the line D are in a relationship of overlapping each other. With such an arrangement, even if the position of the recording element substrate 10 deviates from the predetermined position to a certain extent, the black stripes and the white spots in the recorded image are conspicuous by the drive control of the ejection ports which overlap each other. It can be lost. Even when the plurality of recording element substrates 10 are arranged inline instead of in a staggered arrangement, the recording element substrate 10 is suppressed by the configuration shown in FIG. 12 while suppressing an increase in the length of the liquid ejection head 3 in the recording medium conveyance direction. It is possible to take measures against black streaks and white spots at the joints between them. Here, the outline shape of the recording element substrate 10 is a substantially parallelogram, but the present invention is not limited to this. For example, even when the recording element substrate 10 having a rectangular shape, a trapezoidal shape, or another shape is used, the configuration of the present invention is used. Can be preferably applied.

(Description of Liquid Ejection Device of Second Configuration Example)
The liquid ejection apparatus to which the present invention can be applied is not limited to the above-described first configuration example. Hereinafter, an inkjet recording apparatus 1000 (hereinafter, also referred to as a recording apparatus), which is a second configuration example of the liquid ejection apparatus according to the present invention, will be described. FIG. 13 shows a schematic configuration of a recording apparatus 1000 which is a liquid ejection apparatus of the second configuration example. In the following description, only the parts different from the first configuration example will be mainly described, and the description of the same parts as the first configuration example will be omitted.

The recording apparatus 1000 illustrated in FIG. 13 has a first configuration example in which four monochromatic liquid ejection heads 3 corresponding to the respective colors of CMYK are arranged in parallel to perform full-color recording on the recording medium 2. Is different from that of. In the first configuration example, the number of ejection port arrays that can be used per recording liquid of one color is one, whereas in the second configuration example, the number of ejection port arrays that can be used per color is plural ( 20 columns in the example shown in FIG. 20A described later). Therefore, by recording the print data by appropriately distributing the print data to a plurality of ejection port arrays, it is possible to perform very high-speed printing. Further, even if there is a discharge port that does not discharge, reliability is improved by performing the interpolation from the discharge port of another row at a position corresponding to the transport direction L of the recording medium with respect to the discharge port. Is improved. Therefore, the recording apparatus 1000 of the second configuration example is suitable for use in fields such as commercial printing. Similar to the first configuration example, the supply system of the recording apparatus 1000, the buffer tank 1003, and the main tank 1006 are fluidly connected to each liquid ejection head 3. Further, an electric control unit that transmits electric power and an ejection control signal to the liquid ejection head 3 is electrically connected to each liquid ejection head 3. In the second configuration example as well, similarly to the first configuration example, any of the first and second circulation modes shown in FIGS. 2 and 3 can be used.

(Description of liquid ejection head structure)
The structure of the liquid ejection head 3 in the second configuration example will be described with reference to FIG. 14A is a perspective view seen from the side of the surface of the liquid ejection head 3 on which the ejection ports are formed, and FIG. 14B is a perspective view seen from the opposite direction to FIG. 14A. The liquid ejection head 3 is provided with 16 recording element substrates 10 arranged in a straight line in the longitudinal direction thereof, and is an inkjet line type liquid ejection head capable of recording with a recording liquid of a single color. is there. The liquid ejection head 3 includes a liquid connection portion 111, a signal input terminal 91, and a power supply terminal 92, as in the first configuration example. However, since the liquid ejection head 3 has a larger number of ejection port arrays than that of the first configuration example, the signal input terminals 91 and the power supply terminals 92 are arranged on both sides of the liquid ejection head 3. This is to reduce the voltage drop and the signal transmission delay that occur in the wiring portion provided on the recording element substrate 10.

FIG. 15 shows each component or unit that constitutes the liquid ejection head 3 of the second configuration example, divided for each function. The roles of the units and members and the order of liquid circulation in the liquid ejection head 3 are basically the same as those in the first configuration example, but in the second configuration example, the rigidity of the liquid ejection head 3 is increased. The functions to secure the are different. In the first configuration example, the liquid ejection unit rigidity is mainly secured by the liquid ejection unit support portion 81, but in the liquid ejection head of the second configuration example, the second flow path member 60 included in the liquid ejection unit 300 is used. The rigidity of the liquid ejection head is ensured. The liquid ejecting unit support portion 81 in the second configuration example is connected to both ends of the second flow path member 60, and the liquid ejecting unit 300 is mechanically coupled to the carriage of the recording apparatus 1000 to generate the liquid. The ejection head 3 is positioned. The liquid supply unit 220 including the negative pressure control unit 230 and the electric wiring board 90 are coupled to the liquid ejection unit support 81. A filter (not shown) is built in each of the two liquid supply units 220. In the second configuration example, two types of pressure control are not performed for each negative pressure control unit 230. One of the two negative pressure control units 230 is set to control the pressure with a relatively high negative pressure as a high pressure side negative pressure control unit, and is relatively to the other as a low pressure side negative pressure control unit. It is set to control the pressure with a low negative pressure. As shown in FIG. 15, when the high-pressure side and low-pressure side negative pressure control units 230 are installed at both ends in the longitudinal direction of the liquid ejection head 3, a common supply flow extending in the longitudinal direction of the liquid ejection head 3 is provided. The liquid flows in the passage 211 and the common recovery passage 212 face each other. By doing so, heat exchange between the common supply passage 211 and the common recovery passage 212 is promoted, and the temperature difference in these common passages is reduced. Therefore, there is an advantage that a temperature difference is unlikely to occur in each of the recording element substrates 10 provided along the common supply flow path 211 and the common recovery flow path 212, and recording unevenness due to the temperature difference hardly occurs.

Next, details of the flow path forming member 210 of the liquid ejection unit 300 will be described. As shown in FIG. 15, the flow path forming member 210 is formed by stacking the first flow path member 50 and the second flow path member 60, and ejects liquid such as recording liquid supplied from the liquid supply unit 220 to each ejection module. Distribute to 200. Further, the flow path forming member 210 functions as a recovery flow path member for returning the liquid refluxed from the discharge module 200 to the liquid supply unit 220. The second flow path member 60 of the flow path forming member 210 is a member in which the common supply flow path 211 and the common recovery flow path 212 are formed, and also has a function mainly responsible for the rigidity of the liquid ejection head 3. .. Therefore, the material of the second flow path member 60 is preferably one having sufficient corrosion resistance to liquid such as recording liquid and high mechanical strength, and specifically, stainless steel, titanium (Ti), alumina, etc. are preferably used. be able to.

Next, the details of the first flow path member 50 and the second flow path member 60 will be described with reference to FIG. 16. 16A shows the surface of the first flow path member 50 on the side to which the discharge module 200 is attached, and FIG. 16B shows the back surface thereof, which is in contact with the second flow path member 60. The side on the right side is shown. Unlike the first configuration example, the first flow path member 50 in the second configuration example is an arrangement in which a plurality of members corresponding to each discharge module 200 are arranged adjacent to each other. By adopting such a divided structure, by arranging a plurality of such modules, it becomes possible to meet the length required for the liquid ejection head 3. This configuration can be particularly suitably applied to, for example, a liquid ejection head having a relatively long length corresponding to the JIS (Japanese Industrial Standard) B2 size and dimensions larger than that. As shown in FIG. 16A, the communication port 51 of the first flow path member 50 is in fluid communication with the discharge module 200, and as shown in FIG. 16B, individual communication of the first flow path member 50 is performed. The port 53 is in fluid communication with the communication port 61 of the second flow path member 60. FIG. 16C shows the surface of the second flow path member 60 that is in contact with the first flow path member 50, and FIG. 16D is the central portion in the thickness direction of the second flow path member 60. FIG. 16E shows a surface of the second flow path member 60 on the side in contact with the liquid supply unit 220. The functions of the flow path and the communication port of the second flow path member 60 are the same as those for the recording liquid for one color in the first configuration example. One of the common flow channel 71 of the second flow channel member 60 is the common supply flow channel 211 shown in FIG. 17, and the other is the common recovery flow channel 212, which are arranged along the longitudinal direction of the liquid ejection head 3. Liquid is supplied from one end side to the other end side. In this configuration example, unlike the first configuration example, the liquids flow in the common supply channel 211 and the common recovery channel 212 in opposite directions along the longitudinal direction of the liquid ejection head 3.

FIG. 17 shows the connection relationship of each flow path between the recording element substrate 10 and the flow path constituting member 210. As shown in FIG. 16, a pair of common supply flow channel 211 and common recovery flow channel 212 extending in the longitudinal direction of the liquid ejection head 3 are provided in the flow channel constituent member 210. The communication port 61 of the second flow channel member 60 is connected in alignment with the individual communication port 53 of each first flow channel member 50, and is connected from the communication port 72 of the second flow channel member 60 to the common supply flow channel. A liquid supply path communicating with the communication port 51 of the first flow path member 50 via 211 is formed. Similarly, a liquid supply path that communicates from the communication port 72 of the second flow channel member 60 to the communication port 51 of the first flow channel member 50 via the common recovery flow channel 212 is also formed.

FIG. 18 shows a cross section taken along the line FF of FIG. As shown in this figure, the common supply channel 211 is connected to the discharge module 200 via the communication port 61, the individual communication port 53, and the communication port 51. Although not shown in FIG. 18, it is apparent from FIG. 17 that the common recovery channel 212 is connected to the discharge module 200 through a similar path in another cross section. Similar to the first configuration example, each ejection module 200 and the printing element substrate 10 are formed with a flow path communicating with the pressure chamber 23 where each ejection port 13 is formed. A part or all of the supplied liquid can be recirculated through this pressure passage through the pressure chamber 23 corresponding to the discharge port 13 in which the discharge operation is stopped. Further, as in the first configuration example, the common supply passage 211 is connected to the high pressure side negative pressure control unit 230, and the common recovery passage 212 is connected to the low pressure side negative pressure control unit 230 via the liquid supply unit 220. It is connected. Therefore, due to the differential pressure generated by the negative pressure control unit 230, a flow that flows from the common supply flow passage 211 through the pressure chamber 23 of the recording element substrate 10 to the common recovery flow passage 212 is generated.

(Explanation of discharge module)
Next, the discharge module 200 in the second configuration example will be described. 19A is a perspective view of the discharge module 200, and FIG. 9B is an exploded view thereof. The difference from the first configuration example is that a plurality of terminals 16 are arranged on both sides (each long side of the recording element substrate 10) of the recording element substrate 10 along the direction of the plurality of ejection openings, and are electrically connected to the terminals 16. Two flexible wiring boards 40 are also arranged for one printing element substrate 10. This is because the number of ejection port rows provided on the recording element substrate 10 is, for example, 20 rows, which is significantly larger than the four rows of the first configuration example. That is, an object is to suppress the maximum distance from the terminal 16 to the recording element 15 provided corresponding to the ejection port array to be short so as to reduce the voltage drop and the signal transmission delay occurring in the wiring portion in the recording element substrate 10. I am trying. Further, the liquid communication port 31 of the support member 30 is opened so as to straddle all the ejection port arrays provided on the recording element substrate 10. The other points are the same as those in the first configuration example.

(Description of structure of recording element substrate)
Next, the configuration of the recording element substrate 10 in the second configuration example will be described. 20A is a plan view of the surface of the recording element substrate 10 on the side where the ejection ports 13 are formed, and FIG. 20B shows the portion where the liquid supply passage 18 and the liquid recovery passage 19 are formed. FIG. 20(c) is a plan view of the side corresponding to the back surface of FIG. 20(a). Here, FIG. 20B shows a state in which the lid member 20 provided on the back surface side of the recording element substrate 10 in FIG. 20C is removed. As shown in FIG. 20B, the liquid supply paths 18 and the liquid recovery paths 19 are alternately provided on the back surface side of the printing element substrate 10 along the ejection port array direction. Although the number of ejection port arrays is significantly larger than that of the first configuration example, the essential difference from the first configuration example is that the terminals 16 are arranged in the ejection port array direction of the recording element substrate 10 as described above. It is arranged on both sides along the line. A set of a liquid supply path 18 and a liquid recovery path 19 is provided for each ejection port array, an opening 21 that communicates with the liquid communication port 31 of the support member 30 is provided in the lid member 20, and the like. The basic configuration is similar to that of the first configuration example.

(Explanation of liquid concentration)
Next, in the configuration in which the liquid such as the recording liquid circulates in the pressure chamber 23 as described above, the evaporation of the water content or the solvent component from the ejection port 13 and the concentration of the liquid will be described in more detail with reference to FIG. To do. 21A is a plan view schematically showing the vicinity of the pressure chamber 23 in the recording element substrate 10 shown in FIGS. 10 and 11 described above, and FIG. 21B is an X- line of FIG. 21A. It is sectional drawing in a X-ray. The supply port 17a and the recovery port 17b are located outside the range shown by these figures, but in these figures, the flow path 27a connecting the supply port 17a and the pressure chamber 23, the pressure chamber 23, and the recovery port 17b. A flow path 27b that connects the two is schematically shown. Here, it is assumed that the liquid to be ejected from the ejection port 13 is a recording liquid used for inkjet recording, for example. The recording liquid is obtained by dissolving a dye which is a solute or a pigment which is a dispersoid in water or another solvent (or dispersion medium). The recording liquid existing in the flow paths 27a and 27b and the pressure chamber 23 is shown in gray scale, and in particular, the light and shade in the gray scale conceptually shows the dye or pigment concentration in the recording liquid. The darker the color, the higher the dye concentration or pigment concentration. An arrow 401 in the figure indicates the flow direction of the recording liquid in the flow paths 27a and 27b. This flow is caused by a pressure difference (differential pressure) between the liquid supply path 18 communicating with the supply port 17a and the liquid recovery path 19 communicating with the recovery port 17b.

The recording liquid forms a meniscus at the end of the opening surface of the ejection port 13 of the ejection port forming member 12, and is in contact with the atmosphere outside the liquid ejection head 3. When the liquid ejection head 3 is left in a state in which the surface on which the ejection port 13 is formed is not specially protected by covering the surface with the ejection port 13 or the like, as shown by an arrow 402 in FIG. Water and solvent components evaporate from it. As a result, with the circulation of the recording liquid, the recording liquid whose solute concentration or dispersoid concentration has increased flows in the circulation direction shown by the arrow 401 in the drawing, and the solute concentration or the dispersoid concentration is reduced on the downstream side of the pressure chamber 23. The increased recording liquid will be accumulated. When the liquid discharge head 3 is used for a long time, the recording liquid having an increased solute concentration or dispersoid concentration circulates in the recording device 1000, so that the solute concentration or the dispersoid concentration in the recording liquid increases in the entire recording device 1000. However, the recording quality may be deteriorated. When the concentration of the recording liquid in the entire recording device 1000 rises in this way, all the recording liquid in the recording device 1000 including each tank must be replaced in order to obtain good recording quality. There is.

FIG. 22 schematically shows, as a comparative example, a recording element substrate 10 provided with an ejection port and a recording element that are not actually involved in the ejection of the recording liquid as described in Japanese Patent Laid-Open Publication No. 2004-242242. 3 is an enlarged plan view of an end portion of the recording element substrate 10. FIG. It is assumed that a plurality of ejection openings 13 are arranged in a line to form an ejection opening array, and a recording element is provided corresponding to each ejection opening 13. The printing elements 15 are arranged in a row corresponding to the ejection port row to form a printing element row, and at least one printing element 15b that is not related to ejection is provided at both ends of the printing element row. Here, the recording element 15b that is not related to ejection is a dummy recording element that is not driven to eject the recording liquid. The ejection port forming member 12 is provided with ejection ports 13b corresponding to the recording elements 15b. In other words, at least one dummy printing element 15b is provided at the end of the printing element array, and the remaining printing elements in the printing element array are the printing elements 15 related to ejection. Since the recording element 15b does not participate in ejection, the ejection port 13b also does not participate in ejection. The discharge ports 13b that are not related to this discharge are located at the ends of the discharge port array. The recording element 15b is provided so that the recording element 15 actually involved in the ejection of the recording liquid has uniform characteristics over the entire area in the arrangement direction of the recording elements without being affected by the end effect in etching. There is. On the surface of the ejection port forming member 12 on the substrate 11 side, elongated recesses 25 extending in the ejection port array direction are formed in order to form a plurality of pressure chambers 23. The recesses 25 form the ejection ports 13b and recording. It extends to the position of the element 15b. In the liquid ejection head 3 having the recording element substrate 10 shown in FIG. 22, a meniscus of the recording liquid is also formed at the ejection port 13b, and the water or solvent component is evaporated from the ejection port 13b. In this way, by providing the ejection ports 13b, which are not related to ejection, at the column ends of the ejection port array, evaporation of water and solvent components is promoted by the amount of the ejection ports 13b, and the recording liquid in the liquid ejection head is ejected. Concentration is accelerated. As a result, the increase in the recording liquid concentration during long-term use is accelerated, and the deterioration of the recording quality occurs at an early stage.

(First embodiment)
FIG. 23 is a diagram for explaining the liquid ejection head according to the first embodiment of the present invention, and is an enlarged plan view schematically showing an end portion of the recording element substrate 10. The recording element substrate 10 described below can be used in the liquid ejection head 3 in any of the liquid ejection devices of the above-described first and second configuration examples. Here, for ease of explanation, only a portion related to one ejection port array of the printing element substrate 10 as shown in FIGS. 10 and 11, for example, is shown, but the printing element substrate 10 has a plurality of ejection ports. An outlet row can be provided. A printing element array is formed on the first surface of the substrate 11 corresponding to the ejection port array, and the second surface on the opposite side of the first surface of the substrate 11 has a structure shown in FIGS. A liquid supply path 18 and a liquid recovery path 19 are provided as in the case shown in FIG. Further, a supply port 17 a and a recovery port 17 b penetrating the substrate 11 are provided so that the liquid supply path 18 and the liquid recovery path 19 communicate with the pressure chamber 23.

In the liquid ejection head 3 of the present embodiment, the recording element substrate 10 is the same as that shown in FIG. 22, but a dummy recording element 15b which is not related to ejection is provided, but this recording element 15b is provided. The difference is that the corresponding ejection port 13b is not provided. In the illustrated example, the recess 25 provided on the surface of the ejection port forming member 12 on the substrate 11 side is formed so as to extend to a position corresponding to the formation position of the recording element 15b. Therefore, a space that is similar to the pressure chamber 23 but does not communicate with the ejection port 13 is formed in a region including the formation position of the recording element 15b. A pressure chamber-like space 23b is formed in this space. The pressure chamber-like space 23b also communicates with the supply port 17a and the recovery port 17b. In this configuration, the recording element 15 is formed corresponding to each of the ejection ports 13 forming the ejection port array to configure the recording element array, and at least one end of the recording element array is defined as the ejection port. It means that the recording element 15b which does not correspond is formed. The recording element 15 corresponding to the ejection port 13 is provided inside the pressure chamber 23 communicating with the ejection port 13 and is electrically connected to, for example, the above-described terminal 16. Then, the recording element 15 can apply energy for ejection to the liquid in the corresponding pressure chamber 23 according to the drive signal.

As described in the section of the background art, when a recording element is formed by etching the element material, there is a tendency that the etching progresses faster at the position of the end portion of the recording element array, that is, there is an etching end effect. The dimensions and thickness of the element tend to be small. Therefore, in the structure shown in FIG. 23, a dummy recording element 15b that does not correspond to the ejection port and therefore cannot participate in ejection is provided, and the effect of the faster etching progress is the formation of the recording element 15b. I try to stay within the range. In other words, the influence of the circulation of the etching liquid that may occur at both ends of the recording element array is prevented by the dummy recording element 15b from reaching the recording element 15 that is actually involved in the ejection, corresponding to the ejection port 13. There is. Therefore, various characteristics of the printing element are uniform over the entire area of the printing element 15 relating to ejection, and good printing can be performed.

Further, in the liquid ejection head 3 of this embodiment, the ejection port 13 is provided only for the recording element 15 so as to be involved in ejection, and no ejection port that is not involved in ejection is provided. For this reason, as compared with the one shown in FIG. 22, excess water and solvent components are not evaporated from the ejection ports regardless of ejection, the concentration of the recording liquid rises slowly, and the recording quality is maintained for a long time. It is possible to perform recording without deterioration. In the illustrated example, one dummy recording element 15b is provided at each end of the recording element array, but the number of dummy recording elements 15b is not limited to this, and each dummy recording element 15b is provided. There may be a plurality for each end. The dummy recording element 15b has the same configuration as the recording element 15 actually involved in ejection except for the influence of the end effect of etching, but since it is not involved in ejection, it is electrically connected to the terminal 16. It may or may not be provided with a wiring for.

(Second embodiment)
In the recording element substrate 10 according to the first embodiment shown in FIG. 23, the pressure chamber-like space 23b is formed for the recording element 15b that is not related to ejection, but the pressure is applied to the dummy recording element 15b that is not related to ejection. It is also possible not to form the chamber-like space 23b. FIG. 24 is a diagram illustrating the liquid ejection head according to the second embodiment of the present invention, and is an enlarged plan view schematically showing the end portion of the recording element substrate 10. In the second embodiment shown in FIG. 24, the elongated concave portion 25 formed on the surface of the ejection port forming member 12 on the substrate 11 side is not formed up to the position of the dummy recording element 15b. The pressure chamber-like space 23b is not provided at the position of the recording element 15b.

In the line type recording apparatus as shown in FIGS. 1 to 20, the recording element substrate 10 should have as much edge as possible so that good recording can be performed in all areas including the joints between the recording element substrates 10. The recording element 15, the pressure chamber 23, and the ejection port 13 related to ejection are provided up to the portion. Therefore, the dummy recording element 15b, which is not related to ejection, is generally provided on the end side of the substrate 11 with respect to the liquid supply passage 18 and the liquid recovery passage 19 formed on the second surface of the substrate 11. .. On the other hand, in the method of laminating the resin on the first surface of the substrate 11 which is currently the mainstream as the method of manufacturing the ejection port forming member 12, generally, the resin in the portion corresponding to the pressure chamber 23 and the recess 25 is developed. The pressure chamber 23 and the recess 25 are formed by removing with a liquid. At this time, the developing solution flows out from the discharge port 13, the supply port 17a, and the recovery port 17b. As shown in FIG. 23, when the pressure chamber-like space 23b is provided corresponding to the dummy recording element 15b, the developer flowing out for forming the pressure chamber-like space 23b has no ejection port. Therefore, all must be discharged from the supply port 17a and the recovery port 17b. Since the dummy recording element 15b is provided on the end side of the substrate 11 with respect to the liquid supply path 18 and the liquid recovery path 19, it is naturally formed at a position far from the supply port 17a and the recovery port 17b. .. Further, when a minute droplet is discharged from the discharge port 13 to perform high-definition recording, the height of the pressure chamber 23, that is, the height of the recess 25 is also extremely small, for example, 14 μm. For this reason, in the pressure chamber-shaped space 23b at the end of the recording element substrate 10, a stagnant portion is generated and the developer does not easily flow out, which may adversely affect manufacturing defects. Therefore, as shown in FIG. 24, the pressure chamber 23 or a space similar thereto is provided only for the recording element 15 relating to the ejection, in other words, only for the ejection port 13, so that the developer stays By eliminating the portion, it is possible to suppress adverse effects such as manufacturing defects.

(Method of manufacturing recording element substrate)
Next, a method for manufacturing the recording element substrate 10 in the liquid ejection head according to the present invention, particularly a preferable method for manufacturing the ejection port forming member 12, will be described with reference to FIG. Here, a method of manufacturing the recording element substrate 10 according to the second embodiment shown in FIG. 24 will be described. The method described here is the method of manufacturing the recording element substrate 10 according to the first embodiment shown in FIG. Can also be applied to. FIG. 25 is a diagram showing a manufacturing method by a cross section taken along line YY of FIG. 24, wherein (a-1) to (a-3) show steps of a method by general photolithography in order, and b-1) to (b-3) show steps by a suitable method in order.

As a method of manufacturing the recording element substrate 10 of the liquid ejection head, methods shown in (a-1) to (a-3) of FIG. 25 are known. First, the substrate 11 on which the recording element 15 and the dummy recording element 15b are already provided, and the supply port 17a and the recovery port 17b (neither of which are shown in FIG. 25) are prepared. The recording element 15 and the dummy recording element 15b are simultaneously formed on the surface of the substrate 11, that is, the first surface in the same manufacturing process. A protective film or the like may be formed on the surface of the substrate 11 including the surfaces of the recording element 15 and the dummy recording element 15b. As shown in (a-1), a mold member 452 having a shape corresponding to the pressure chamber 23 and the recess 25 is formed on the surface of the substrate 11 by using photolithography or the like. Next, as shown in (a-2), in order to form the discharge port forming member 12, the shape member 452 is covered with the resin layer 453 having fluidity so as to penetrate into the gap between the shape members 452. Then, as shown in (a-3), the ejection port 13 is formed in the resin layer 453 by photolithography or the like, and the resin layer 453 and the mold material 452 at the position of the ejection port 13 are removed by development. As a result, the ejection port forming member 12 is completed and the recording element substrate 10 is obtained. In this method, since the resin layer 453 having fluidity is used, as shown in (a-2), the thickness of the resin layer 453 tends to be thinner on the end portion side of the substrate 11 than on other portions. Is. Therefore, the shape of the ejection port 13 on the end side of the substrate 11 tends to be more inclined than that of the central portion of the substrate 11, which may cause deterioration of recording quality.

Next, a suitable method for manufacturing the recording element substrate 10 of the liquid ejection head 3 according to the present invention will be described with reference to (b-1) to (b-3) of FIG. First, a first resin layer is formed using a dry film or the like on the surface of the substrate 11 similar to that described with reference to FIG. 25(a-1), and (b-1 ), an exposed region 455 and a non-exposed region 456 are formed. The exposure region 455 is a region that is a part of the ejection port forming member 12, and particularly includes a region corresponding to the partition wall 22. The non-exposure region 456 is a region corresponding to the recess 25 provided in the ejection port forming member 12, and particularly includes a region corresponding to the pressure chamber 23. Next, as shown in (b-2), a second resin layer 457 is formed using a dry film or the like so as to cover the exposed region 455 and the non-exposed region 456. Then, the ejection port 13 is exposed by photolithography, and as shown in (b-3), the region of the ejection port 13 and the region of the recess 25 including the pressure chamber 23 are collectively developed and removed. As a result, the ejection port forming member 12 is completed and the recording element substrate 10 is obtained. According to this method, as shown in (b-2), it is possible to suppress the thickness of the ejection port forming member 12 from becoming thin at the position of the end portion of the substrate 11, and as a result, it is possible to suppress deterioration of the recording quality. it can.

In the liquid discharge heads of the respective embodiments described above, since the discharge ports are connected to correspond only to the recording elements related to discharge, it is possible to suppress evaporation of excess water and solvent components, and to prevent solutes and dispersoids in the liquid. The rate of increase in concentration is suppressed. As a result, by using the liquid ejection head of each embodiment, it is possible to perform printing for a long period of time without lowering the printing quality. In addition, since the recording elements that do not relate to ejection are provided at the end portions of the recording element array because they do not have corresponding ejection openings, the characteristics of the recording elements are It becomes uniform and good recording can be performed. In the above description, the liquid discharge head is of the line type, but the liquid discharge head according to the present invention is not limited to this, and the present invention is also applicable to, for example, a serial scan type liquid discharge head. The configuration of can be preferably applied.

10 Recording Element Substrate 11 Substrate 12 Discharge Port Forming Member 13 Discharge Ports 15 and 15b Recording Element 17a Supply Port 17b Recovery Port 23 Pressure Chamber

Claims (6)

A substrate on which a plurality of recording elements that generate energy for ejecting liquid are provided on a first surface;
An ejection port forming member that is provided on the first surface side and that has a plurality of ejection ports that eject the liquid, and that forms a pressure chamber that communicates with the substrate between the ejection ports and the substrate. ,
A supply port and a recovery port penetrating the substrate between the first surface and a second surface opposite to the first surface and communicating with the plurality of pressure chambers;
A recording element substrate having
The plurality of recording elements are arranged in a row on the first surface to form a recording element row,
At least one dummy printing element is provided at an end of the printing element array, and the remaining printing elements are printing elements relating to ejection,
A recording element used for a liquid ejection head in which a recording element related to the ejection is arranged inside the pressure chamber for each of the pressure chambers, and the plurality of ejection ports are provided corresponding to only the recording element related to the ejection. A method of manufacturing an element substrate, comprising:
Forming a first resin layer on the first surface of the substrate on which the recording element array is formed and exposing an area including a formation position of the pressure chamber;
A step of forming a second resin layer on the first resin layer after exposing the first resin layer, and exposing the area to be the ejection port;
Developing the pressure chamber and the discharge port by performing development after exposure to the second resin layer,
A manufacturing method comprising: Recording element of the dummy in the liquid discharge head, in the direction of the printing element array, than the formation position of the supply port and the recovery port is provided on the end side of the substrate, according to claim 1 Manufacturing method . The liquid discharge head includes means for flowing the liquid from the supply port to the recovery port through the pressure chamber, and the liquid inside the pressure chamber is circulated between the liquid outside the pressure chamber and the outside. the process according to claim 1 or 2. The liquid discharge head, on the second surface of the substrate, a liquid supply path communicating with the pressure chamber via the supply port, and a liquid recovery path communicating with the pressure chamber via the recovery port, And a flow of the liquid from the liquid supply path to the liquid recovery path through the supply port, the pressure chamber, and the recovery port according to a pressure difference between the liquid supply path and the liquid recovery path. The manufacturing method according to claim 3 , wherein: Wherein the plurality of said recording element substrate in the liquid discharge head, wherein the recording elements are arranged in the direction of the column, the production method according to any one of claims 1 to 4. A substrate on which a plurality of recording elements that generate energy for ejecting liquid are provided on a first surface;
An ejection port forming member that is provided on the first surface side and that has a plurality of ejection ports that eject the liquid, and that forms a pressure chamber that communicates with the substrate between the ejection ports and the substrate. ,
A supply port and a recovery port penetrating the substrate between the first surface and a second surface opposite to the first surface and communicating with the plurality of pressure chambers;
A recording element substrate having
The plurality of recording elements are arranged in a row on the first surface to form a recording element row,
At least one dummy printing element is provided at an end of the printing element array, and the remaining printing elements are printing elements relating to ejection,
Recording elements related to the ejection are arranged inside the pressure chambers for each of the pressure chambers, and the plurality of ejection ports are provided corresponding to only the recording elements related to the ejection,
Wherein in response to dummy recording element, characterized in that the pressure chamber-like space not communicating are constituted by said discharge port forming member between the substrate and the discharge port, the liquid discharge head.