JP7094772B2 - Liquid discharge head and liquid discharge device - Google Patents

Description

The present invention relates to a liquid discharge head and a liquid discharge device.

Conventionally, as a liquid discharge method of a liquid discharge head, a thermal method is known in which bubbles are generated in a liquid by heat energy generated by a heat generating element and the liquid is discharged by using the bubbles. The thermal type liquid discharge head has a substrate provided with a heat generating element and a flow path forming member joined to the substrate and provided with a discharge port for discharging the liquid. A flow path communicating with the discharge port is formed between the substrate and the flow path forming member, and a supply path penetrating the substrate and communicating with the flow path is formed on the substrate. The heat generating element is provided at a position corresponding to the discharge port of the substrate.

In a thermal type liquid ejection head that ejects ink as a liquid, a protective film or an insulating film is generally provided at a contact point with the ink for the purpose of protection from the ink and insulation. However, these protective films and insulating films may be dissolved by the ink. Therefore, if the wiring or circuit protected by such a protective film or insulating film is exposed and comes into contact with the ink, and a leak current flows through the ink, the liquid ejection head may malfunction. Therefore, it is necessary to take measures to suppress the malfunction of the liquid ejection head against the dissolution of the protective film and the insulating film by the ink.
Patent Document 1 describes a configuration in which a plurality of wiring layers are formed in a ring shape so as to surround a supply path inside a substrate (interlayer insulating film). The plurality of wiring layers are laminated in the thickness direction of the substrate and are electrically connected to each other and to the substrate via interlayer vias. Therefore, even if a part or all of the plurality of wiring layers is exposed to the supply path due to the dissolution of the substrate (interlayer insulating film) and comes into contact with the ink, and a leak path is generated between the wiring layer and the ink, the current flowing into the wiring layer. Will escape to the substrate (ground potential). As a result, it is possible to suppress the leakage current from flowing to other wirings and circuits, and to suppress the influence that the liquid discharge head causes a malfunction.

US Pat. No. 7,594,713

However, in the above configuration, the plurality of wiring layers are wiring layers that are electrically independent from the wiring for driving the energy generating element such as a heater, and usually no potential is applied to the wiring layer. Therefore, when the insulating film is melted, the current flowing from the ink to the substrate through the wiring layer is small, so that it is difficult to detect it, and therefore, it is difficult to detect the melting by the ink. Therefore, dissolution may proceed from between the interlayer vias and the wiring layer itself may be dissolved, which may cause a malfunction of the liquid discharge head.
Therefore, an object of the present invention is to provide a liquid discharge head and a liquid discharge device that can detect the dissolution of a substrate by a liquid and thereby suppress a malfunction.

In order to achieve the above-mentioned object, the liquid discharge head of the present invention penetrates a substrate including an insulating film, an energy generating element provided on the substrate and generating energy used for discharging the liquid, and the substrate. A wiring layer formed inside the insulating film of the substrate and used to drive the energy generating element, and a wall forming the flow path. It has a wiring layer that is arranged at intervals from the above and is arranged so as to surround the flow path when the substrate is viewed in a plan view, and the wiring layer is connected to a leak detection mechanism that detects a leak current flowing from the wiring layer. , A liquid discharge head.
Further, the liquid discharge device of the present invention has the above-mentioned liquid discharge head and a leak detection mechanism that is electrically connected to the wiring layer and detects a leak current flowing from the wiring layer.
According to such a liquid discharge head and a liquid discharge device, when the insulating film is dissolved by the liquid through the flow path and the wiring layer is exposed to the flow path and comes into contact with the liquid, the wiring layer (high potential) to the liquid ( Leakage current will flow to (low potential). This leak current can be easily detected by connecting a leak detection mechanism to the wiring layer. Therefore, when the leak current is detected, the liquid discharge operation can be stopped or the liquid discharge head can be replaced, and it is possible to prevent the liquid discharge head from causing a malfunction. ..

As described above, according to the present invention, it is possible to detect the dissolution of the substrate by the liquid, thereby suppressing the malfunction of the liquid discharge head and the liquid discharge device.

It is a top view which shows the structural example of the liquid discharge head which concerns on 1st Embodiment. It is a block diagram which shows the circuit structure example of the liquid discharge apparatus which concerns on 1st Embodiment. It is a top view which shows the wiring layout of the substrate which concerns on 1st Embodiment. It is sectional drawing which shows the structural example of the substrate which concerns on 1st Embodiment. It is sectional drawing which shows the structural example of the substrate which concerns on 2nd Embodiment. It is sectional drawing which shows the structural example of the substrate which concerns on 3rd Embodiment. It is sectional drawing which shows the structural example of the substrate which concerns on 3rd Embodiment. It is a schematic block diagram which shows the inkjet recording apparatus. It is a perspective view which shows the inkjet recording head.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification, as the liquid ejection head of the present invention, a liquid ejection head that ejects ink and records an image on a recording medium will be described as an example, but it can also be applied to a liquid ejection head that ejects other liquids. Is. Further, a thermal method is adopted in which a heat generating element is used as a recording element (energy generating element) to generate bubbles and discharge a liquid, but a recording element substrate in which a piezo method and various other liquid discharging methods are adopted. The present invention can also be applied. The present invention can also be used as a recording element substrate of an industrial recording apparatus such as biochip fabrication, electronic circuit printing, and application of a resist for forming a circuit pattern of a semiconductor wafer.

(First Embodiment)
FIG. 1 is a plan view showing a configuration example of a liquid discharge head according to the first embodiment of the present invention. The liquid discharge head 10 has a substrate 100 including a base material made of silicon, and a flow path forming member (not shown) having a plurality of discharge ports for discharging liquid is joined to the substrate 100. There is. A plurality of flow paths communicating with a plurality of discharge ports are formed between the substrate 100 and the flow path forming member, and a plurality of supply paths penetrating the substrate 100 and communicating with the plurality of flow paths are formed in the substrate 100. Is formed. On the surface of the substrate 100, a supply port row 101 composed of openings (supply ports) of a plurality of supply paths is formed. Between the two supply port rows 101, a heater row 102 in which a plurality of heat generating elements (heaters) as energy generating elements for generating energy used for discharging the liquid are arranged is formed. A drive element unit 103 and a heater selection circuit unit 104 are provided adjacent to the two supply port rows 101 and the heater row 102. The drive element unit 103 and the heater selection circuit unit 104 are each composed of a plurality of drive elements and a plurality of heater selection circuits provided corresponding to the plurality of heaters. At the end of the substrate 100, a recording data supply circuit 105 and a pad row 106 for electrically connecting to the outside are provided. The heater selection circuit unit 104 outputs a drive signal based on the recorded data from the recorded data supply circuit 105, and the drive element unit 103 outputs the recorded data from the recorded data supply circuit 105 and the drive signal from the heater selection circuit unit 104. And drive the corresponding heater. As a result, ink is ejected from the corresponding ejection port. The outer shape of the substrate 100 is not limited to the parallelogram shown in the figure, but may be a rectangle or another shape.
The liquid discharge head 10 was supplied to the heater from the supply port by making one of the two supply port rows 101 provided on both sides of the heater row 102 a row of collection ports for collecting the liquid. An ink circulation configuration may be used in which ink is collected from a collection port.

FIG. 2 is a block diagram showing a circuit configuration example of a liquid discharge device including the liquid discharge head of the present embodiment.
The liquid discharge head 200 includes a plurality of heater units 203 each of which is a heater and a drive element for driving the heater, a plurality of heater selection circuits 206 corresponding to the plurality of heater units 203, and a recording data supply circuit 207. It is provided. The plurality of heater units 203 are connected to the heater power supply wiring 201 that supplies the power supply potential to the heater and the heater ground wiring 202 that supplies the reference potential to the heater. The plurality of heater selection circuits 206 are connected to a logic power supply wiring 204 that supplies a power supply potential to a logic circuit including the heater selection circuit 206, and a logic ground wiring 205 that supplies a reference potential to the logic circuit. The recorded data supply circuit 207 is connected to a plurality of heater units 203 and a plurality of heater selection circuits 206.
In the main body 208 of the liquid discharge device, the heater power supply wiring 201 is connected to the heater power supply 209 via the leak detection mechanism 210, and the logic power supply wiring 204 is connected to the logic power supply 211 via the leak detection mechanism 212. .. Further, in the main body 208, the heater ground wiring 202 is connected to the ground wiring 214 via the leak detection mechanism 215, and the ground wiring 214 is connected to the ground wiring 213 connected to the ground power supply. The logic ground wiring 205 is connected to the ground wiring 213. In the illustrated example, three types of power supplies are shown, but the number of power supplies is not limited to this, and the leak detection mechanism is also arranged for all power supplies, but a specific power supply is used. May be placed only in.

FIG. 3 is a plan view showing an example of the layout of the heater power supply wiring or the heater ground wiring formed on the substrate of the present embodiment.
The substrate 100 is provided with a plurality of heaters 301, a plurality of supply paths 302, and a conductive layer 303 (wiring layer) which is a heater power supply wiring or a heater ground wiring. As will be described later, the substrate 100 has a silicon base material and an insulating film formed on the silicon base material. The conductive layer 303 is a so-called solid layer provided inside the insulating film, and is arranged at a predetermined distance from the wall surface 304 forming each supply path 302 as shown in the drawing, so that the substrate 100 is viewed in a plan view. Then, it is arranged so as to surround the supply path 302. As a result, the wiring resistance is reduced by increasing the wiring area of the conductive layer 303 in response to the recent increase in the substrate area, the high density of the heater 301, and the increasing tendency of the heater drive current due to the increase in the potential of the heater power supply. It can be suppressed. As a result, it is possible to suppress the influence of the variation in the discharge energy and realize good image formation. A protective film may be formed on the wall surface 304 of the supply path 302.

Further, due to the above-mentioned arrangement of the conductive layer 303, when the protective film or the insulating film is melted by the ink through the supply path 302, the wall surface 304 of the supply path 302 recedes and the conductive layer 303 is exposed to the supply path 302, the heater power supply wiring Or the heater ground wiring comes into contact with the ink. For example, when the heater power supply wiring comes into contact with the ink, a leak path is generated from the heater power supply wiring to the silicon base material, other wiring, or the like through the ink, and a leak current flows. Further, when the protective film on the heater is connected to, for example, a ground potential or a certain potential, a leak path is also generated from the ink to this protective film.
On the other hand, the heater ground wiring is often at a potential higher than the ground potential of the silicon substrate because a large current for driving the heater flows into the heater ground wiring. Therefore, when the heater ground wiring comes into contact with the ink, a leak current may flow from the heater ground wiring to the silicon substrate (ground potential) through the ink.
In the present embodiment, even when such a leak current occurs, a power leak detection mechanism is provided corresponding to each power supply as described above, so that the current or voltage can be used by using this power leak detection mechanism. It is possible to detect the occurrence of leakage current based on the change in. As a result, the dissolution of the protective film or the insulating film by the ink can be detected as a power leak. Therefore, when a power leak is detected, the liquid discharge operation can be stopped or the liquid discharge head can be replaced, and as a result, it is possible to prevent the liquid discharge head from causing a malfunction. It will be possible. In particular, the heater power supply wiring is wiring that supplies the power supply potential to the heater, and a higher potential (for example, about 32V) than the heater ground wiring, the logic power supply wiring, and the logic ground wiring, which are other wiring layers, is applied. Therefore, since the leak current generated when the heater power supply wiring comes into contact with the ink is large, the leak can be detected with high sensitivity. Therefore, a configuration in which a power leak detection mechanism is provided for the heater power supply wiring is more preferable. When the ink is in contact with the silicon base material and connected to the ground potential, for example, even if a leak path from the heater power supply wiring occurs, the leak current flows to the silicon base material, which has an effect. It can be minimized.

In order to detect melting by ink through the supply path 302, for example, a configuration in which a linear wiring is arranged around the supply path 302 to detect a change in resistance value, disconnection, or leakage current can be considered. However, in such a configuration, since the ends of the wiring cannot be connected to each other in order to secure the current path, there will always be a place where the wiring is not arranged around the supply path 302, and ink is used at that place. If dissolution occurs, it cannot be detected. On the other hand, in the present embodiment, since the conductive layer 303 is arranged so as to surround the entire circumference of the supply path 302 when the substrate 100 is viewed in a plan view, it becomes possible to more reliably detect the dissolution by the ink. ..

4 (a) and 4 (b) are schematic cross-sectional views taken along the line AA of FIG. 3, and show a configuration example of the substrate of the present embodiment. FIG. 4A corresponds to the case where the heater power supply wiring is arranged around the supply path 302, and FIG. 4B corresponds to the case where the heater ground wiring is arranged.

As shown in FIGS. 4A and 4B, the substrate 100 has a silicon base material 401, an interlayer insulating film 402, and four wiring layers 403 to 406. The interlayer insulating film 402 is formed on the silicon base material 401, and the four wiring layers 403 to 406 are formed so as to be spaced apart from each other in the thickness direction of the substrate 100 with the interlayer insulating film 402 interposed therebetween. A protective film 407 is formed on the interlayer insulating film 402.
The first wiring layer 403 is a wiring layer including at least one of a logic signal wiring, a logic power supply wiring, and a logic ground wiring for transmitting a logic signal to a logic circuit such as a heater selection circuit and a recorded data supply circuit. The second wiring layer 404 is a wiring layer including at least one of the logic signal wiring, the logic power supply wiring, and the logic ground wiring, like the first wiring layer 403. The first wiring layer 403 and the second wiring layer 404 may be layers having the same function, and each includes, for example, a logic signal wiring, a logic power supply wiring, and a logic ground wiring. You can go out. Alternatively, the first wiring layer 403 and the second wiring layer 404 may be layers having different functions, for example, the first wiring layer 403 includes logic signal wiring, and the second wiring layer 404 It may include logic power supply wiring and logic ground wiring. The third wiring layer 405 is a solid wiring which is a heater power supply wiring, and the fourth wiring layer 406 is a solid wiring which is a heater ground wiring. Here, the solid wiring is wiring provided so as to be electrically connected to a plurality of heater rows 102 in common, and since a wide wiring area is secured over the surface of the substrate 100, the wiring resistance thereof. It is a configuration that can suppress.
In the configuration examples shown in FIGS. 4A and 4B, the first wiring layer 403 and the first wiring layer 403 and the first wiring layer 403 are used to detect the leakage current by using the third wiring layer 405 or the fourth wiring layer 406. The wiring layer 404 of 2 may not be provided so as to surround the supply path 302. Further, the first wiring layer 403 and the second wiring layer 404 are arranged by routing a plurality of wirings having different functions such as logic signal wiring, logic power supply wiring, and logic ground wiring. Therefore, the first wiring layer 403 and the second wiring layer 404 are usually not solid wiring, and their wiring resistance is higher than that of the third wiring layer 405 and the fourth wiring layer 406.

In the configuration example shown in FIG. 4A, of the four wiring layers 403 to 406, the third wiring layer 405, which is the heater power supply wiring, is arranged closest to the wall surface 304 of the supply path 302. Therefore, the dissolution of the interlayer insulating film 402 by the ink through the supply path 302 can be detected as a leak of the heater power supply. In this configuration example, since the heater power supply is a high potential power supply (for example, about 32V), it becomes easy to detect the current change due to the leakage current, and it becomes possible to detect the occurrence of the power supply leakage with higher sensitivity. That is, from the viewpoint of the detection sensitivity of the occurrence of a power supply leak, the third wiring layer 405, which is the heater power supply wiring, is provided closer to the wall surface 304 of the supply path 302 than the other wiring layers. Is preferable.
In the configuration example shown in FIG. 4B, of the four wiring layers 403 to 406, the fourth wiring layer 406, which is the heater ground wiring, is arranged closest to the wall surface 304 of the supply path 302. Therefore, when the potential (reference potential) of the heater ground wiring is higher than the ground potential, the dissolution of the interlayer insulating film 402 by the ink through the supply path 302 can be detected as a leak of the ground power supply. In this configuration example, since the leak current flows from the heater ground wiring, the influence of the leak current can be minimized.

Of the four wiring layers 403 to 406, which wiring layer includes what kind of wiring is not limited to the above example, and is arbitrary. For example, the four wiring layers 403 to 403 to Any of the 406s may constitute the heater power supply wiring. Further, the number of wiring layers is not limited to four, and may be five or more, and even in that case, which wiring layer includes what kind of wiring is arbitrary.

(Second embodiment)
5 (a) and 5 (b) are views corresponding to schematic cross-sectional views taken along the line AA of FIG. 3, showing a configuration example of the substrate according to the second embodiment of the present invention.
The wiring arranged around the supply path 302 for detecting the dissolution of the interlayer insulating film 402 by the ink is not limited to the heater power supply wiring and the heater ground wiring, and may be a logic power supply wiring. That is, the dissolution of the interlayer insulating film 402 by the ink through the supply path 302 may be detected as a leak of the logic power supply. In this embodiment, of the four wiring layers 403 to 406, the first wiring layer 403 including the logic power supply wiring or the second wiring layer 404 is arranged closest to the wall surface 304 of the supply path 302. Therefore, it is different from the first embodiment. Other configurations are the same as those of the first embodiment, and only the differences from the first embodiment will be described below.

In the configuration example shown in FIG. 5A, the first wiring layer 403 is arranged closest to the wall surface 304 of the supply path 302. As described above, the first wiring layer 403 is a wiring layer including at least one of the logic signal wiring, the logic power supply wiring, and the logic ground wiring, but here, at least the logic power supply wiring is included. Further, the wiring layer arranged closest to the wall surface 304 of the supply path 302 in the first wiring layer 403 is the logic power supply wiring. Therefore, when the interlayer insulating film 402 is dissolved by the ink through the supply path 302 and the ink comes into contact with the first wiring layer 403, the above-mentioned dissolution by the ink through the supply path 302 is performed by the same principle as in the case of the heater power supply. Can be detected as a leak in the logic power supply. At this time, since the potential of the logic power supply is lower than that of the heater power supply (for example, about 3.3 V), the leakage current from the logic power supply is relatively small, and therefore the influence of the leak current can be minimized. can. Further, the leak detection of the logic power supply is advantageous in that monitoring during image formation is easier than in the case of a heater power supply in which a current flows during image formation.
Further, in the configuration example shown in FIG. 5B, the second wiring layer 404 is arranged closest to the wall surface 304 of the supply path 302, but similarly to the configuration example shown in FIG. 5A, The second wiring layer 404 includes at least the logic power supply wiring. Further, the wiring layer arranged closest to the wall surface 304 of the supply path 302 in the second wiring layer 404 is the logic power supply wiring. Therefore, similar to the configuration example shown in FIG. 5A, the dissolution of the interlayer insulating film 402 by the ink through the supply path 302 can be detected as a leak of the logic power supply.

(Third embodiment)
6 (a), 6 (b), 7 (a), and 7 (b) are the AA lines of FIG. 3, showing a configuration example of the substrate according to the third embodiment of the present invention. It is a figure corresponding to the schematic cross-sectional view along.
This embodiment is different from the first embodiment in that two of the four wiring layers 403 to 406 are arranged closer to the wall surface 304 of the supply path 302 than the other wiring layers. It's different. Other configurations are the same as those of the first and second embodiments, and only the differences from the first and second embodiments will be described below.

In the configuration example shown in FIG. 6A, the third wiring layer 405, which is the heater power supply wiring, and the fourth wiring layer 406, which is the heater ground wiring, are arranged close to the wall surface 304 of the supply path 302. The third wiring layer 405 and the fourth wiring layer 406 are arranged so as to surround the supply path 302 when the substrate 100 is viewed in a plan view. As a result, as the melting of the interlayer insulating film 402 by the ink through the supply path 302 progresses, one or both of the third wiring layer 405 and the fourth wiring layer 406 first come into contact with the ink. Therefore, the dissolution of the interlayer insulating film 402 by the ink can be detected by one or both of the leak of the heater power supply and the leak of the ground power supply, and the detection accuracy of the dissolution by the ink can be further improved. Further, when both the third wiring layer 405 and the fourth wiring layer 406 come into contact with the ink, the leakage current is from the third wiring layer 405, which is the high potential heater power supply wiring, to the fourth wiring, which is the heater ground wiring. A current flows through the wiring layer 406 and from there to the silicon substrate 401. As described above, in the configuration example of FIG. 6A, the third wiring layer having a large potential difference as compared with the configuration example of FIG. 4A in which only the heater power supply wiring is close to the wall surface 304 of the supply path 302. Leakage current can flow from 405 to the fourth wiring layer 406. Therefore, it is possible to detect the leak current with higher sensitivity. Further, since the leak current flows from the fourth wiring layer 406 to the silicon base material 401, it is possible to suppress heat generation due to the leak current and the influence on other circuits. Here, as described above, the fourth wiring layer 406, which is the heater ground wiring, is configured as solid wiring, and is wired more than the first wiring layer 403 and the second wiring layer 404, which are wirings connected to the logic circuit. The resistance is low. Therefore, from the viewpoint of suppressing heat generation due to the leak current and the influence on other circuits, the third wiring layer 405 which is the heater power supply wiring and the fourth wiring layer 406 which is the heater ground wiring are connected to the supply path 302. A configuration provided close to the wall surface 304 is preferable. In this configuration, both the third wiring layer 405 and the fourth wiring layer 406 are close to the wall surface 304 of the supply path 302 and have a large area, so that the wiring resistance can be suppressed low. Therefore, it is possible to further suppress the influence on the image formation due to the variation in the discharge energy.
In the configuration example shown in FIG. 6A, the first wiring layer 403 and the second wiring layer 404 may not be provided so as to surround the supply path 302.

In the configuration example shown in FIG. 6B, at least the first wiring layer 403 including the logic power supply wiring and the second wiring layer 404 including at least the logic power supply wiring are arranged close to the wall surface 304 of the supply path 302. There is. Therefore, in this case as well, if either the first wiring layer 403 or the second wiring layer 404 comes into contact with the ink, the dissolution of the interlayer insulating film 402 by the ink through the supply path 302 is detected as a leak of the logic power supply. can do. Therefore, the accuracy of detecting the dissolution by the ink can be further improved. In the configuration example shown in FIG. 6B, one of the first wiring layer 403 and the second wiring layer 404 may include at least the logic power supply wiring, and the other may include at least the logic ground wiring. In that case as well, when both the first wiring layer 403 and the second wiring layer 404 come into contact with the ink, a leakage current flows through the ink between the first wiring layer 403 and the second wiring layer 404. , It becomes possible to detect the dissolution of the interlayer insulating film 402 by the ink.

In the configuration example shown in FIG. 7A, the third wiring layer 405 and the first wiring layer 403 are arranged close to the wall surface 304 of the supply path 302, but the first wiring layer 403 is at least logic. Includes ground wiring. Further, in the configuration example shown in FIG. 7B, the third wiring layer 405 and the second wiring layer 404 are arranged close to the wall surface 304 of the supply path 302, which is shown in FIG. 7A. Similar to the configuration example, the second wiring layer 404 includes at least the logic ground wiring. Therefore, in the configuration example shown in FIGS. 7 (a) and 7 (b), when both of the two wiring layers come into contact with the ink, the leakage current flows from the heater power supply wiring to the logic ground wiring through the ink, which has an effect. Can be suppressed.
In the configuration examples shown in FIGS. 7 (a) and 7 (b), the fourth wiring layer 406 (heater ground wiring) is used in the supply path 302 instead of the third wiring layer 405 (heater power supply wiring). It may be arranged close to the wall surface 304. In this case as well, if both of the two wiring layers come into contact with the ink, a leak path to the logic ground wiring through the ink can be generated, and the influence of the leak current can be suppressed.
In a configuration in which the two wiring layers are arranged closer to the wall surface 304 of the supply path 302 than the other wiring layers as in the present embodiment, one of the two wiring layers is a heater power supply wiring or This is wiring that supplies power potential, such as logic power wiring. Further, the other wiring layer of the two wiring layers is a wiring for supplying a reference potential such as a heater ground wiring and a logic ground wiring, and is connected to the silicon base material 401. Since one wiring layer has a higher potential than the other wiring layer and a leakage current flows from the ground wiring to the silicon base material 401, the influence of the leakage current can be suppressed.

In the above-described embodiment, in order to detect the dissolution of the protective film and the insulating film by the ink, the wiring (power supply wiring, ground wiring, logic power supply wiring) used for driving the heat generating element (heater) is used. It was explained by giving an example. By detecting the leak current using such wiring, it is possible to detect the leak current without providing a dedicated wiring or pad for detecting the leak current. In order to detect the leak with high sensitivity, it is preferable to detect the leak current by using a wiring to which a potential of 3.0 V or higher is applied, such as a heater power supply wiring and a logic power supply wiring. Further, in order to detect the leak with higher sensitivity, it is more preferable to detect the leak current by using a wiring to which a potential of 20 V or more is applied, such as a heater power supply wiring.
Although the configuration in which the conductive layer connected to the leak detection mechanism surrounds the supply path 302 when the substrate 100 is viewed in a plan view has been described, a recovery path for collecting ink is provided in addition to the supply path 302. If so, it may be provided so as to surround the recovery path. That is, the conductive layer may be provided so as to surround the flow path penetrating the substrate 100 such as the supply path 302 and the recovery path.

(Inkjet recording device)
As a liquid ejection device to which this embodiment can be applied, an inkjet recording apparatus 1000 (hereinafter, also referred to as a “recording apparatus”) that ejects ink for recording will be described with reference to FIG. 8 showing a schematic configuration thereof. The recording device 1000 includes a transport unit 1 for transporting the recorded medium 2 and a line-type liquid discharge head unit 3 arranged substantially orthogonal to the transport direction of the recorded medium 2, and a plurality of recorded media 2 are provided. It is a line type recording device that continuously records in one pass while continuously or intermittently transporting the media. The recording medium 2 is not limited to cut paper, and may be continuous roll paper. The liquid discharge head unit 3 is capable of full-color printing with four color inks of cyan (C) / magenta (M) / yellow (Y) / black (K). Further, the liquid discharge head unit 3 is electrically connected to a control unit of a recording device 1000 for transmitting electric power and a discharge control signal to the liquid discharge head unit 3.

(Liquid discharge head unit)
FIG. 9 is a perspective view of the liquid discharge head unit 3 according to the present embodiment. In the liquid ejection head unit 3, one recording element substrate (liquid ejection head) 10 can eject inks of four colors of C / M / Y / K, respectively, on a straight line of the recording element substrate (liquid ejection head) 10. It is a line-type liquid discharge head unit that is individually arranged (arranged inline).
As shown in FIG. 9, the liquid discharge head unit 3 includes a recording element substrate (liquid discharge head) 10, a flexible wiring board 40, and an electrical wiring board 90. Further, the electric wiring board 90 includes a signal input terminal 91 and a power supply terminal 92. These signal input terminals 91 and power supply terminals 92 are electrically connected to the control unit of the recording device 1000, and the discharge drive signal and the electric power required for discharge are transmitted through these terminals to the recording element substrate (liquid discharge head). ) 10 is supplied.

Although the present embodiment is a so-called line-type head unit having a length corresponding to the width of the recorded medium 2, a so-called serial type liquid discharge that records while scanning the recorded medium 2 is performed. The present invention can also be applied to a head unit. Examples of the serial type liquid ejection head unit include a configuration in which a recording element substrate for black ink and a recording element substrate for color ink are mounted.

100 Substrate 200 Liquid discharge head 302 Supply path (flow path)
303 Conductive layer (wiring layer)

Claims (19)

A substrate containing an insulating film and
An energy generating element provided on the substrate and generating energy used for discharging a liquid, and an energy generating element.
A flow path formed through the substrate and communicating with a discharge port for discharging a liquid,
A wiring layer formed inside the insulating film of the substrate and used to drive the energy generating element, which is arranged at a distance from a wall forming the flow path and is viewed in a plan view. It has a wiring layer arranged so as to surround the flow path, and has.
A liquid discharge head in which the wiring layer is connected to a leak detection mechanism that detects a leak current flowing from the wiring layer . The liquid discharge head according to claim 1 , wherein the wiring layer is a power supply wiring that supplies a power supply potential to the energy generating element. The liquid discharge head according to claim 1 , wherein the wiring layer is a power supply wiring that supplies a power supply potential to a logic circuit for driving the energy generating element. Another wiring layer formed inside the insulating film so as to be separated from the wiring layer in the thickness direction of the substrate and used to drive the energy generating element, and is spaced from the wall forming the flow path. Further has other wiring layers arranged in place,
The liquid discharge head according to claim 1 , wherein the wiring layer is arranged closer to a wall forming the flow path than the other wiring layers. The liquid discharge head according to claim 4 , wherein the wiring layer is a power supply wiring that supplies a power supply potential to the energy generating element. The liquid discharge head according to claim 1 , further comprising the two wiring layers formed inside the insulating film so as to be separated from each other in the thickness direction of the substrate. The liquid discharge head according to claim 6 , wherein one of the two wiring layers has a higher potential than the other of the two wiring layers. Another wiring layer formed inside the insulating film so as to be separated from the two wiring layers in the thickness direction of the substrate and used to drive the energy generating element, and is a wall forming the flow path. Has other wiring layers spaced apart from
The liquid discharge head according to claim 6 or 7 , wherein the two wiring layers are arranged closer to the wall forming the flow path than the other wiring layers. One of the two wiring layers constitutes a power supply wiring that supplies a power supply potential to the energy generating element, and the other of the two wiring layers is a ground wiring that supplies a reference potential to the energy generating element. The liquid discharge head according to claim 8 . The other wiring layer includes a logic signal wiring that transmits a signal to a logic circuit for driving the energy generating element, a power supply wiring that supplies a power supply potential to the logic circuit, and a ground that supplies a reference potential to the logic circuit. The liquid discharge head according to claim 9 , which comprises at least one of the wirings. One of the two wiring layers constitutes a power supply wiring that supplies a power supply potential to the energy generating element, and the other of the two wiring layers is a reference potential in a logic circuit for driving the energy generating element. The liquid discharge head according to claim 8 , which constitutes the ground wiring for supplying the energy. One of the two wiring layers constitutes a power supply wiring that supplies a power supply potential to a logic circuit for driving the energy generating element, and the other of the two wiring layers drives the energy generating element. The liquid discharge head according to claim 8 , wherein the ground wiring for supplying a reference potential to the logic circuit for the purpose is configured. The liquid discharge head according to any one of claims 1 to 12, wherein a potential of 3.0 V or more is applied to the wiring layer. The liquid discharge head according to any one of claims 1 to 13, wherein the liquid supplied to the flow path is connected to the ground potential. A substrate containing an insulating film and
An energy generating element provided on the substrate and generating energy used for discharging a liquid, and an energy generating element.
A flow path formed through the substrate and communicating with a discharge port for discharging a liquid,
A wiring layer formed inside the insulating film of the substrate and used to drive the energy generating element, which is arranged at a distance from a wall forming the flow path and is viewed in a plan view. A wiring layer arranged around the flow path and
With a liquid discharge head,
A leak detection mechanism that is electrically connected to the wiring layer and detects a leak current flowing from the wiring layer.
Liquid discharge device with. The liquid discharge device according to claim 15 , wherein the wiring layer is a power supply wiring that supplies a power supply potential to the energy generating element. The liquid discharge device according to claim 15 , further comprising the two wiring layers formed inside the insulating film so as to be separated from each other in the thickness direction of the substrate. Another wiring layer formed inside the insulating film so as to be separated from the two wiring layers in the thickness direction of the substrate and used to drive the energy generating element, and is a wall forming the flow path. Has other wiring layers spaced apart from
The liquid discharge device according to claim 17 , wherein the two wiring layers are arranged closer to the wall forming the flow path than the other wiring layers. One of the two wiring layers constitutes a power supply wiring that supplies a power supply potential to the energy generating element, and the other of the two wiring layers is a ground wiring that supplies a reference potential to the energy generating element. The liquid discharge device according to claim 18 .

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