JPH0781064A - Ink jet recording head - Google Patents

Abstract

PURPOSE:To provide an ink jet recording head enhanced in responce and capable of performing high speed recording. CONSTITUTION:A channel groove 3 and an ink reservior 4 are formed to a channel substrate 1 by anisotropic etching and a heater 7 is formed to a heater substrate 2 and, after an electrode and a protective film are formed on the heater substrate 2, an insulating layer 8 and a thick film resin layer 9 are formed on the heater substrate 2. First and second recessed parts 10,11 are formed to the insulating layer 8 and the thick film resin layer 9 by patterning. The first recessed part 10 has the extended part 15 extending from the part provided with the heater 7 toward the ink reservior 4. The first recessed part 10 receives the supply of ink from the extended part thereof after the air bubble produced on the heater 7 disappears. Therefore, the supply capacity of ink in the first recessed part 10 is enhanced and the refilling with ink is performed at a high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head for recording by ejecting ink droplets from nozzles by the pressure of bubbles generated by heat generated by a heater.

[0002]

2. Description of the Related Art The ink jet recording system is capable of high-speed recording and produces almost no noise during recording.
Since it can print directly on plain paper and does not require fixing processing, it is drawing attention because it can be downsized. As a method for producing an ink jet recording head, for example, JP-A-61-230954 and JP-A-1-230954 are available.
There is a manufacturing technique described in Japanese Patent No. 148560.

FIG. 8 is a structural view of an example of a conventional ink jet recording head, FIG. 8A is a sectional view taken perpendicularly to the axial direction of the channel groove, and FIG. 8B is FIG. A)
It is the top view cut | disconnected by BB of FIG. Further, FIG. 9 is a perspective view of a main part of a channel substrate in an example of a conventional inkjet recording head. In the figure, 1 is a channel substrate, 2 is a heater substrate, 3 is a channel groove, 4 is an ink reservoir, 5
Is a nozzle, 6 is an unetched portion, 7 is a heater, 8 is an insulating layer, 9 is a thick resin layer, 10 is a first concave portion, 11 is a second concave portion, 12 is a partition wall, 13 is an ink droplet, and 14 is It is recording paper.

In this ink jet recording head, a channel groove 3 which constitutes a nozzle for ejecting ink by anisotropic etching is formed on a Si wafer which is a channel substrate 1, and an ink reservoir which supplies ink to the channel portion from the outside. 4 is formed, and the opening of the channel groove 3 serves as the nozzle 5.

The anisotropic etching technique for Si wafers is generally based on the fact that the etching rate of {111} crystal faces is very slow compared to other crystal faces. When a silicon substrate having a {100} crystal face on the surface is used, a pattern with square or rectangular openings is
It is known that they can be formed with extremely high precision, and that the shape of connecting them deteriorates the accuracy of the connecting portion. Therefore, in the channel substrate 1, as shown in the perspective view of FIG. 6, the channel groove 3 formed by anisotropic etching and the ink reservoir 4 are formed in a separated pattern, and in the middle thereof. The unetched portion 6 remains.
Therefore, it is necessary to form a flow path that connects the channel groove 3 and the ink reservoir 4. The flow path connecting the channel groove 3 and the ink reservoir 4 forms one second recess 11 for each channel groove, thereby connecting the ink reservoir 4 and each channel groove 3.

A heater 7 is formed on the heater substrate 2,
An electrode for supplying a drive current, a protective film, and the like are formed on the heater 7, but details of these are omitted. Further, on the heater substrate 2, an insulating layer 8 and a thick film resin layer 9 are formed. Further, by patterning the insulating layer 8 and the thick film resin layer 9, the above-described second recess 11 and the first recess 10 provided on the heater 7 are formed.

The first concave portion 10, which is called a pit, is formed by patterning the insulating layer 8 and the thick resin layer 9, and suppresses the lateral growth of bubbles generated on the heater 7, It is intended to prevent deviation of the nozzle from the nozzle 5 and suction of air. In addition, the second recess 11
In order to protect wirings, drive circuits, and the like (not shown) disposed under the insulating layer 8 from the invasion of ink, the insulating layer 8 is left in the lower portion and is placed at a position corresponding to the unetched portion 6 of the channel substrate 1. The thick resin layer 9 is formed by patterning.

After the channel substrate 1 and the heater substrate 2 formed as described above are bonded, they are cut and separated into individual head chips to manufacture a recording head.

In such an ink jet recording head, since the opening area of the first recess 10 is small, the ink flows around the channel groove 3 and is filled in the first recess 10 after the ink is ejected. There is a problem that the resistance is high, it takes time until the ink is refilled and stable ink ejection is possible, and the recording speed cannot be improved.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and can be achieved without increasing the manufacturing cost.
It is an object of the present invention to provide an ink jet recording head having improved responsiveness and capable of high speed recording. In addition,
Another object is to provide an inkjet recording head that prevents ejection abnormalities due to clogging of dust and reduces the effects of crosstalk and the like.

[0011]

According to a first aspect of the present invention, in an ink jet recording head for recording by ejecting ink from a nozzle, an ink flow path connected to the nozzle and the ink flow path are connected. A heater provided on the substrate corresponding to the flow path, and a thick film resin layer deposited after the heater is provided on the substrate, and the thick film resin layer is formed on the heater. A concave portion extending in a direction opposite to the nozzle side is formed.

Further, in the invention described in claim 2,
In an inkjet recording head for recording by ejecting ink from nozzles, a first substrate having a plurality of channel portions connected to the nozzles and an ink reservoir portion, and a plurality of heaters corresponding to the channel portions are provided. A second substrate having a thick film resin layer formed on the substrate, wherein the thick film resin layer has a first recess formed on the heater and extending toward the ink reservoir; A second concave portion provided corresponding to the portion and connecting the channel portion and the ink reservoir portion, and a communication groove provided between the heater and the second concave portion to communicate the respective channel portions. The first recess is connected to the communication groove at a portion extending to the ink reservoir side.

[0013]

According to the present invention, by extending the recess on the heater in the direction opposite to the nozzle side, after the bubbles generated on the heater are contracted, the ink is transferred from the extended portion of the recess to the heater. Then, the ink is refilled. At this time, since the ink only moves in parallel, refilling is completed at a higher speed than in the conventional case where ink is refilled by sneaking around from the channel section, so the time required for the next ink ejection operation is shortened. It is possible to improve responsiveness and enable high speed recording.

Further, in the invention according to the second aspect, a communication groove for communicating each channel portion is provided, and the first recess on the heater is connected to the communication groove, so that the second recess is dusted or bubbled. It can function as a filter for removing dust and prevents dust from entering the channel portion by supplying ink from another channel portion through the communication groove when dust or bubbles are clogged in the second recess. , It is possible to prevent jetting abnormality due to clogging of dust. At this time, since the first recess is connected to the communication groove, the ink is refilled from the communication groove quickly, and high-speed response can be ensured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a constitutional view of a first embodiment of an ink jet recording head of the present invention. FIG. 1 (A) is a sectional view taken perpendicularly to the axial direction of a channel groove, and FIG. 1) is a sectional view taken along line BB in FIG. 1A, and FIG. 1C is a sectional view taken along line C-C in FIG. 1B. In the figure, FIG.
The same parts as those in FIG. 9 are denoted by the same reference numerals and the description thereof will be omitted. Reference numeral 15 is an extension portion.

The channel groove 3 and the ink reservoir 4 are formed in the channel substrate 1 by anisotropic etching. Also,
A heater 7 is formed on the heater substrate 2, an electrode for supplying a drive current to the heater 7, a protective film, and the like are formed, and an insulating layer 8 and a thick resin layer 9 are further formed. The thickness of the insulating layer 8 is 0.5 to 30 μm, preferably 3 to 10
μm, and can be set to 5 μm, for example. This thickness is sufficient to protect the wiring portion and the drive circuit located under the insulating layer 8 from the invasion of ink. The thickness of the thick film resin layer 9 is 5 to 50 μm, preferably 15 to 30 μm
m, which may be, for example, 22 μm. This thickness depends on the flatness of the thick film resin layer 9 and the ink droplet ejection state,
It is determined from the ink supply speed. The insulating layer 8 can be formed of the same material as the thick film resin layer 9 to form a multi-layered thick film resin layer, or the insulating layer 8 can be formed of a material different from that of the thick film resin layer 9, for example, SiO ₂ Inorganic materials such as PSG and other materials, and other materials can also be used. A first concave portion 10 and a second concave portion 11 are formed in the insulating layer 8 and the thick film resin layer 9 by patterning. Such an ink jet recording head can be manufactured, for example, by the method described in JP-A-1-148560.

As shown in FIG. 1B, the first concave portion 10 has an extending portion 15 extending from the portion where the heater 7 is arranged to the ink reservoir 4 side. In FIG. 1, the first concave portion 10 including the extending portion 15 has a rectangular shape, but the present invention is not limited to this. For example, the extending portion 15 may be tapered toward the ink reservoir 4 or may have a staircase. It can be formed into various shapes such as being formed into a shape. Further, the second recess 11 is provided independently corresponding to each channel groove 3.

When the heater 7 is driven by the drive circuit, the heater 7 generates heat and bubbles are generated on the heater 7.
The generated bubbles cause the ink in the channel groove 3 to be ejected from the nozzle 5 as an ink droplet 13. After that, the bubbles disappear and the ink is refilled. Ink is supplied from the ink reservoir 4 to the channel groove 3 through the second recess 11. At this time, in the first concave portion 10, the ink is also supplied from the extending portion of the first concave portion on the heater 7 in which bubbles are generated. Therefore, the refilling of the ink in the first recess 10 is performed faster than in the conventional case. This enables high-speed recording.

By the way, the ink used in the ink jet recording apparatus undergoes a filtration step in its manufacturing process. In addition, since the ink filling operation into the ink cartridge is also performed in an extremely clean environment, dust or particles of a size of about several tens of microns, which are clogged in the channel groove 3 of the recording head, are usually not contained in the ink. Not included. However, in the process of loading the ink cartridge into the recording apparatus, dust may enter the ink from the joint portion that connects the ink cartridge and the recording head and enter the ink flow path of the recording head. Further, dust and the like may remain in the ink reservoir 4 in the process of cutting and separating the head chip in the process of manufacturing the head, and in the process of assembling the separated head chip together with the printed circuit board, the heat sink, etc. as a recording head. . In this case, since the opening (inlet) of the ink reservoir 4 is sufficiently large, dust and particles having a size of about several tens of microns pass through, but the second recess 11 connecting the channel groove 3 and the ink reservoir 4 does not. Since the thick film resin layer 9 forming the concave portion cannot be made too thick, the channel cross-sectional area of the portion corresponding to the unetched portion 6 of the channel substrate 1 is small, which causes dust to stagnant and hinders ink supply to the channel. Sometimes.

As a head structure for preventing dust from entering the print head, a structure in which a filter is externally attached to the inlet of the ink reservoir is considered. But,
This structure adds a step of mounting the filter to the head chip, which increases the manufacturing cost. Further, it is not possible to remove dust left in the reservoir during the head manufacturing process.

A structure for dealing with such dust and the like can be added to the ink jet recording head of the present invention. Hereinafter, the ink jet recording head of the present invention to which a structure for dealing with dust and the like is added will be described.

FIG. 2 is a constitutional view of a second embodiment of the ink jet recording head of the present invention, which is shown in FIG.
Is a cross-sectional view taken along a line perpendicular to the axial direction of the channel groove.
2B is a cross-sectional view taken along the line BB of FIG.
FIG. 2C is a sectional view taken along line C-C in FIG.
In the figure, parts similar to those in FIG. 1 are assigned the same reference numerals and explanations thereof are omitted. Reference numeral 16 is a communication passage.

In this embodiment, the second recess 11 is independently provided corresponding to each channel groove 3, and the communication passage 16 for connecting the channel groove 3 is thick between the heater 7 and the second recess 11. It is formed on the film resin layer 9. Second recess 11
Has a small cross-sectional area, so dust that has entered through the opening (inlet) of the ink reservoir 4 and the ink reservoir 4
It is possible to prevent dust remaining on the channel 3 from entering the channel groove 3. Further, for example, when dust or air bubbles are clogged in the second recess 11 by the communication passage 16,
Ink is supplied from the peripheral channel groove 3 to the channel groove 3 corresponding to the second recess 11 filled with dust or the like via the communication passage 16, so that defective ink ejection can be prevented.

In this embodiment, the extension 15 of the first recess 10 connects the first recess and the communication passage 16. Therefore, even if the ink is supplied through the communication passage 16 after the bubbles generated on the heater 7 are extinguished, the ink can be bent only once from the communication passage 16 toward the first recess 10. Is supplied, the flow path resistance is small, and ink refilling can be performed at high speed. Of course, the communication passage 16 and the first recess 10 may not be connected, but in that case, the communication passage 1
When the ink is supplied via 6, the ink is supplied once to the channel groove 3 and then to the first concave portion 10, and the flow path becomes complicated to increase the flow path resistance. Refills may be slightly slower. However, even in this case, since the first concave portion 10 has the extending portion 15, it is possible to realize ink refilling at a higher speed than in the past.

As a modified example of the second embodiment, the connecting passage 16 is formed on the thick film resin layer 9 between the first recess 10 and the nozzle 5.
It may be configured to be provided in the. Also, the channel groove 3
The communication passage 16 may be provided on the side wall of the.

In the above-described second embodiment, the divided second recesses are provided in the same number as the channel grooves and at intervals corresponding to the channel grooves. It is not limited to those shown in the examples. For example, it is possible to have two second recesses for one channel groove.

FIG. 3 is a constitutional view of a third embodiment of the ink jet recording head of the present invention, FIG. 3 (A) is a sectional view taken perpendicularly to the axial direction of the channel groove, and FIG. 3 (B). Is
It is sectional drawing cut | disconnected by the BB line of FIG. 3 (A). In the figure, parts similar to those in FIG. 1 are assigned the same reference numerals and explanations thereof are omitted.

This embodiment shows another structure for dealing with dust and the like. As mentioned above, garbage is second
It is easy to get stuck in the concave part of. Therefore, in order to ensure the ink supply to the channel groove 3 when the dust is clogged, FIG.
As shown in FIGS. 3A and 3B, the second recess 11 is formed.
Are all connected. With this configuration, even if dust is stagnation at the place where the second recess 11 is present, ink can be supplied to the channel groove 3 from both sides thereof.

The ink jet recording head shown in the second and third embodiments and the conventional ink jet recording head were assembled together with a printed circuit board, a heat sink and the like so that they could actually operate on printing. . The assembled inkjet recording head is mounted on a printer, and images are repeatedly printed to evaluate image quality, particularly image defects such as missing dots and thin lines, and compare the inkjet recording head of the present invention with a conventional inkjet recording head. did.

FIG. 4 is an explanatory view of an example of a heater driving method. The driving method used for comparison is as shown in FIG.
The 144 heaters are divided into two from the center, and from the nozzle number 1 at the end and the nozzle number 73 at the center, four nozzles each make up one block, and block numbers 1 to 1 respectively.
It was divided into 18 blocks up to 8 and voltage pulses were applied to the 8 heaters within the same block number at the same timing. Further, the printing order to the blocks is such that 1,7, 13, 4, 10, ... This is to avoid crosstalk due to propagation of pressure pulses, which will be described later.

The evaluation method is as follows:
After continuously printing one sheet of print, maintenance operations such as wiping and priming are performed. Such a printing experiment is repeated 20 times, and after printing a total of 400 prints, the ink cartridge is replaced and the printing experiment is performed again. The cartridge was exchanged 10 times to finish, and image quality defects were evaluated for a total of 4000 prints.

FIG. 5 is an explanatory diagram of the evaluation result of the image quality defect in the printing experiment. As shown in FIG. 5, the second aspect of the present invention
In the case of using the ink jet recording head shown in the example of Example 1, there were some heads in which some dots corresponding to a certain number of nozzles were slightly smaller than those of other nozzles in the initial stage of printing (1 to 400 sheets). , It wasn't a flaw that was a problem. The number of nozzles whose dots became slightly smaller tended to increase as the number of printed sheets increased, but the degree of print defects did not increase. This is because dust left in the ink reservoir 4 during assembly
The ink is ejected to the channel groove 3 side and is clogged in the second concave portion 11 provided individually,
This is because the ink is supplied from the recess 11 to the first recess 10 via the communication passage 16, and from this, the ink is supplied to the channel groove 3 corresponding to the second recess 11 in which dust is stagnant. That is, in the case of a thin image or a line image in which ink is not ejected from the nozzle adjacent to the nozzle corresponding to the second concave portion 11 in which dust is stagnant, the ink is sufficiently supplied. . Also, in the case of a high-density image in which adjacent nozzles are also printed, the ink supply amount will be slightly smaller, but there will be some overlap due to the adjacent dots,
It is considered that even if the dot diameter became small, it did not cause a large printing defect. In addition, dust mixed by the replacement of the ink cartridge also stopped at the second recess, but as described above, ink is supplied to the corresponding channel, and the number of nozzles in which the dots become slightly smaller increases, but image defects occur. Did not become.

On the other hand, in the case of using the head shown in FIG. 5 in which the first concave portion and the second concave portion are independently provided as shown in FIG. There was a head with missing dots and noticeable dot thinning. This defect was not recovered by the maintenance operation. Furthermore, as the number of prints increased, the number of defects increased. This is the second piece of garbage
The reason is that it clogged the concave portion of the above and completely blocked the ink supply path to the channel groove.

In the third embodiment of the present invention shown in FIG. 3, although the number is slightly smaller than that of the conventional ink jet recording head, image defects are observed from the beginning of printing, and the number of defects increases as the number of prints increases. did. In addition, even a maintenance operation may not recover and a larger defect may appear. In this case, when the dust is clogged in the slit-shaped second concave portion 11, the ink is supplied from both sides, but since the cross-sectional area of the flow path is large, the dust is the second concave portion. This is because there is a case where the liquid may pass through the channel groove 3 and enter the channel groove 3 and stagnant in the channel groove 3 portion to hinder the ink supply. In addition, a major defect that appears after the maintenance operation is that if the suction pressure during priming is non-uniform, a plurality of dust particles that have stagnated in the slit-shaped second recess 11 correspond to a specific nozzle having a high suction pressure. It is considered that this is because the ink is supplied to the second concave portion 11 or the channel groove 3 which is concentrated to form a large lump, which hinders the ink supply.

In the third embodiment, as a structure for coping with such a case, for example, the second recessed portion 1 connected to each other is used.
It suffices to form the ink reservoir 4 side of No. 1 like an individual flow path to make the flow path cross-sectional area small. In this case, dust or the like is trapped in the portion of the second recess 11 on the ink reservoir 4 side, but ink can be supplied from the surroundings by the lower portion of the unetched portion 6 or the connecting portion on the channel groove 3 side. . Thereby, it is possible to suppress the image quality defect also in the third embodiment.

FIG. 6 is an explanatory view of another example of the heater driving method. In the ink jet recording head having the same structure as that of the second embodiment, as shown in FIG. 6, there are 144 heaters, each of which has eight nozzles from the end nozzle number 1 to one block, and block numbers 1 to 18 respectively. It was divided into blocks, and voltage pulses were sequentially applied to the eight heaters in the same block number from block 1 to block 18 at the same timing. When the heater is driven in this way, the linearity in the nozzle array direction can be improved as compared with the driving method of the first embodiment.

When a printing experiment was carried out by such a driving method, it was found that small dots were printed in a place where there was no print signal, or that the dot shape was distorted. This is considered to be the effect of so-called crosstalk in which, when a voltage pulse is applied to a certain block, the generated pressure propagates to another flow path through the commonly connected first recesses. That is, in the meniscus vibration at the nozzle after ejection, if a pressure pulse from another channel propagates at the time when the meniscus becomes convex, this pressure may eject a small ink droplet from the nozzle. Further, if the pressure pulse propagates while the meniscus is growing to eject ink droplets, normal ejection may not be performed.

In order to avoid such a phenomenon, blocks which are as far apart as possible are sequentially driven so that the pressure pulse is sufficiently attenuated, and the adjacent blocks are jetted after the meniscus vibration due to the propagating pressure is sufficiently suppressed. However, this driving method has a drawback that the linearity in the nozzle array direction is impaired. Next, a configuration in which the influence of crosstalk is improved without impairing the linearity will be described.

FIG. 7 is a plan view showing a fourth embodiment of the ink jet recording head of the present invention. In the figure, the same parts as those in FIG. In this embodiment, adjacent channel grooves 3 in the same block to which voltage pulses are applied at the same time are connected to each other by a communication path 16, and adjacent blocks are separated from each other by a partition wall 12. Also in this embodiment, the first recess 10
Are connected to the communication passage 16 by the extending portion 15. The second recess 11 is formed individually. Also in this structure, dust is trapped in the second recess 11 provided individually, and does not enter the channel portion. Further, since the ink is supplied from the adjacent second concave portion via the communication passage 16, the ejection abnormality does not occur. When a printing experiment was conducted on the ink jet recording head manufactured with such a structure, small dots and distorted dots that did not correspond to the printing signal were not seen. No image quality defect due to dust was observed.

Also in the above-described third embodiment, crosstalk occurs due to the second recess 11 formed in the slit shape. In order to avoid this, by forming the channel groove 3 side of the second recess 11 in the form of an individual flow path, crosstalk can be suppressed to some extent. In addition, as in the fourth embodiment, the second recess 11 is formed so as to connect the adjacent channel grooves 3 in the same block, and the second recess 11 is separated from the adjacent block. As a result, crosstalk can be further suppressed.

In each of the embodiments described above, the ink jet recording head in which the channel groove and the ink reservoir are formed in the channel substrate and joined to the heater substrate has been described, but the present invention is not limited to this, and for example, the heater substrate. Also, for an ink jet recording head of a type in which after forming the thick film resin layer 8 on another, another thick film resin layer is formed and patterned to form the side wall of the channel groove, and further the top plate is joined, By extending the pit above the heater in the direction opposite to the nozzle, the same configuration as the above-described embodiment can be achieved.

[0042]

As is apparent from the above description, according to the present invention, the recess on the heater is extended in the direction opposite to the nozzle, so that the ink can be refilled at a high speed and the response can be improved. It is possible to provide an ink jet recording head that improves performance and can perform high-speed recording.

Further, by connecting the extending portions of the first recesses on the heater corresponding to some channel grooves to the communicating grooves, individually divided first portions for supplying ink from the ink reservoir to the flow channels. Even if dust or the like is trapped in the second concave portion, the ink can be supplied to the channel groove and the first concave portion at high speed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of an inkjet recording head of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the inkjet recording head of the present invention.

FIG. 3 is a configuration diagram of a third embodiment of an inkjet recording head of the present invention.

FIG. 4 is an explanatory diagram of an example of a heater driving method.

FIG. 5 is an explanatory diagram of evaluation results of image quality defects in a printing experiment.

FIG. 6 is an explanatory diagram of another example of a heater driving method.

FIG. 7 is a plan view showing a fourth embodiment of the inkjet recording head of the present invention.

FIG. 8 is a configuration diagram of an example of a conventional inkjet recording head.

FIG. 9 is a perspective view of a main part of a channel substrate in an example of a conventional inkjet recording head.

[Explanation of symbols]

1 channel substrate, 2 heater substrate, 3 channel groove,
4 ink reservoir, 5 nozzles, 6 unetched portion, 7 heater, 8 insulating layer, 9 thick film resin layer, 10
1st recessed part, 11 2nd recessed part, 12 partition, 13 ink drop, 14 recording paper, 15 extension part, 16 communicating path.

Claims (2)

[Claims] 1. In an inkjet recording head for recording by ejecting ink from a nozzle, an ink flow path connected to the nozzle, a heater provided on a substrate corresponding to the ink flow path, and the substrate Has a thick film resin layer deposited after the heater is disposed, and the thick film resin layer has a recess formed on the heater and extending in a direction opposite to the nozzle side. An inkjet recording head characterized by the above. 2. An ink jet recording head for recording by ejecting ink from nozzles, the first substrate having a plurality of channel portions connected to the nozzles and an ink reservoir portion, and the channel portion corresponding to the first substrate. There is provided a second substrate having a thick film resin layer formed on a substrate having a plurality of heaters, and the thick film resin layer has a first recess formed on the heater and extending toward the ink reservoir. And a second recess provided corresponding to each of the channel parts for connecting the channel part and the ink reservoir part, and a communication groove provided between the heater and the second recess for communicating the channel parts. The inkjet recording head is characterized in that the first recess is connected to the communication groove at a portion extending to the ink reservoir side.