JP5317671B2 - Substrate for liquid discharge head, liquid discharge head, and liquid discharge apparatus - Google Patents

Description

  The present invention relates to a liquid discharge head substrate, a liquid discharge head, and a liquid discharge apparatus.

  Conventionally, as described in Patent Document 1, a liquid discharge head substrate has a layer structure as described below. A heat storage layer for improving thermal efficiency, a heating resistor layer, a wiring layer such as VH for electrical connection to the resistance layer, a heating resistor, and a protective film for protecting the electrode layer from the ink are sequentially formed.

  This liquid discharge head substrate has various measures to reduce the life of the substrate due to the labor saving of electric energy input on the one hand and the mechanical damage due to the foaming of ink and the destruction of the heat generating part due to heat pulses on the other hand. Has been made. In particular, many contrivances have been made for the protective film that protects the heat generating resistor having the heat generating portion located between the pair of wiring patterns from ink.

  From the viewpoint of heat efficiency, it is advantageous that the protective film has a high thermal conductivity or is thin. On the other hand, the protective film serves to protect the wiring connected to the heating element from the ink. From the viewpoint of the defect of the film, the thicker film is more advantageous, and the optimum thickness from the viewpoint of energy efficiency and reliability. Is set to However, the protective film is affected by both cavitation damage due to foaming of ink, that is, mechanical damage, and damage caused by a chemical reaction with the ink component at a high temperature because the surface after foaming becomes high temperature.

  For this reason, it is actually difficult to achieve both an insulating film for protecting the wiring and a film that is stable against mechanical and chemical damage. For this reason, the protective film structure of the liquid discharge substrate forms a highly stable film against mechanical and chemical damage due to ink foaming on the upper layer, and an insulating film to protect the wiring on the lower layer It is common to do. Specifically, a Ta film, which is an extremely high mechanical and chemical stability film, is formed on the upper layer, and a SiN film or SiO film that can be easily formed with an existing semiconductor manufacturing apparatus is formed on the lower layer. Is common.

  As a method for detecting such an abnormality of the protective film, Patent Document 2 discloses an example in which a part of the substrate is exposed and electrically shorted with ink.

Further, as a method of forming a supply port of a liquid discharge head, as one method of micromachining, anisotropic etching of an Si substrate having a <100> plane orientation with an alkaline solution is widely performed. This utilizes the difference in dissolution rate with respect to the alkaline solution depending on the plane orientation. Specifically, the etching proceeds in such a manner that the <111> plane having a very low dissolution rate remains.
JP-A-6-55737 JP-A-9-057973

  As described above, the liquid discharge substrate is configured by the SiN film, the SiO film, or the like so that the heating resistor and the wiring on the substrate electrically connected thereto are not in direct contact with the ink. This is because a stable film can be easily formed on a Si substrate by a semiconductor manufacturing apparatus.

  However, even with the above-described protective film, in some inks, depending on the type of liquid used, the protective film itself may be eroded depending on the use environment conditions (temperature, PH), and the protective film performance may be degraded. is there.

  In such a case, if the defect spreads to the interlayer insulating film of the wiring layer, ink is likely to enter the individual electrode wiring and an electrical short circuit is likely to occur. Then, an abnormality may occur in the heating resistor on the substrate and the wiring on the substrate electrically connected thereto, and the liquid discharge head may not operate normally.

  In some cases, an electrical short circuit affects the electrical connection portion between the main body and the head, which may affect the control board of the liquid ejection apparatus main body.

  Even when an electrical short circuit does not occur, the interlayer insulating film laminated between the protective film, the heating resistor, and the wiring on the substrate electrically connected thereto may be eroded. In this case, since the heat capacity of the entire substrate is reduced, there is a high possibility that a normal function is not exhibited as a liquid discharge head used in a thermal type liquid discharge apparatus using a heating resistor.

  As a countermeasure for the above problem, a method is conceivable in which the ink and the protective film are not brought into contact with each other as much as possible by covering the protective film with which the ink comes into contact with a resin film having high ink erosion resistance. However, in the manufacturing method and configuration of a general liquid discharge head substrate, the end of the protective film is exposed at the end of the supply port.

  That is, even if the contact area between the ink and the protective film can be minimized by the resin film having high ink erosion resistance on the protective film, the erosion of the protective film proceeds from the supply port end. Therefore, even if the protective film can be covered with the highly erodible resin film surface as much as possible, it is difficult to eliminate the erosion of the protective film that proceeds from the supply port end.

  As a result, even if the protective film erodes from the end of the supply port, the presence or absence of protective film erosion should be done so that the effect does not affect the desired performance of the head and the function of the liquid ejection device body. It is necessary to have a means for detecting this.

  In addition, in the method disclosed in Patent Document 2, it is possible to detect an abnormality of the protective film in the manufacturing process, but after the actual shipment, the ink is filled and the protective film performance is deteriorated after a certain period of use. Cannot be detected.

A substrate for a liquid discharge head according to the present invention includes a plurality of heating resistors that generate energy used for discharging a liquid on the surface of the substrate, and wirings electrically connected to the heating resistors, have a, a protective film having an insulating coating at least the wiring, the supply port for supplying the liquid to the surface of the substrate, are formed along the arrangement direction of the plurality of heating resistors liquid ejection Te substrate smell head, the wiring sensing defects in the protective film is used to detect that has arisen, corresponding to between the supply port side end portion and the supply port of the wiring And is provided continuously between the plurality of heating resistors and the supply port along the arrangement direction when viewed from a direction perpendicular to the surface of the substrate. And

  As described above, according to the present invention, the presence or absence of the protective film can be detected with a simple configuration when the abnormality of the protective film occurs during the use period of the liquid ejection head. Further, by outputting the abnormality detection information to the liquid ejection device (printer) main body side, it becomes possible to notify the user of an appropriate time for head replacement.

  The present invention is not limited to the following examples as long as the object of the present invention can be achieved.

(Description of liquid discharge head substrate and liquid discharge head)
FIG. 9 is a diagram illustrating a liquid discharge head and a cartridge to which this embodiment can be applied. Hereinafter, each component will be described with reference to these drawings. However, the present invention is not limited to this.

  The liquid discharge head 21 (hereinafter also simply referred to as a recording head) of the present embodiment is a component that constitutes the cartridge 18. The cartridge 18 includes a recording head 21 and an ink tank 17 that is detachably attached to the recording head 21. The recording head 21 discharges ink (or reaction liquid) supplied from the ink tank 7 from the discharge port through the flow path. For discharging the liquid, thermal energy for foaming the liquid is used.

  The recording head 21 and the cartridge 18 are fixedly supported by positioning means and electrical contacts of a carriage (not shown) placed on the liquid ejection device, and are detachable from the carriage. The ink tank 17a is for black ink, the ink tank 17b is for cyan ink, the ink tank 17c is for magenta ink, and the ink tank 17d is for yellow ink. As described above, since each of the ink tanks 17 (17a, 17b, 17c, 17d) is detachable and each ink tank is replaceable, the running cost of printing in the liquid ejecting apparatus is reduced.

  However, the recording head 21 of the present invention is not limited to this form, and may be a form in which ink is supplied by a tube from an ink tank (not shown) attached to the liquid ejection apparatus main body.

  Next, FIG. 10 is a schematic diagram illustrating a substrate portion mounted on a liquid discharge head to which the present embodiment can be applied, as viewed from the ink discharge direction. This is a schematic front view of a color head for realizing high-density recording used in the present embodiment, showing the arrangement of the ejection port groups of the recording head 21 used in the present embodiment. In this example, the ejection port array in which ejection ports of 600 dpi (dots / inch) per row are arranged is shifted by about 21 μm in the sub-scanning direction (paper feed direction) with respect to each other by 2 rows per color. It is provided for the main scanning direction of the head. A resolution of 1200 dpi is realized. Further, in the illustrated example, such ejection port arrays are juxtaposed so that the color order is the same in both the forward direction and the backward direction in the main scanning direction corresponding to three colors. Further, although the head configuration has an integrated structure that performs recording at 1200 dpi with a total of six ejection port rows for three colors, the head configuration is not limited to this.

  Here, among the cross-sections indicated by the one-dot broken line a-a ′ in the drawing, the region surrounded by the broken line corresponds to the cross-sectional views shown in FIGS.

(Description of liquid ejection device)
FIG. 11 shows an example of a schematic view of a liquid ejection apparatus applied to the present invention.

  In the figure, a carriage 5014 that engages with a spiral groove 5004 of a lead screw 5005 that rotates via driving force transmission gears 5011 and 5009 in conjunction with forward and reverse rotation of a drive motor 5013 has a pin (not shown). And is reciprocated in the directions of arrows a and b. In the carriage 5014, the recording head 21 is mounted together with the ink tank. The recording head 21 is of a type that is fixedly supported by the positioning means and electrical contacts of the carriage 5014 mounted on the liquid ejection apparatus main body IJRA and is detachable from the carriage 5014.

(Information processing method from protective film loss detection circuit)
FIG. 12 is a conceptual diagram showing how the liquid ejection apparatus main body processes information on the presence or absence of a protective film defect from the detection means of the present invention.

  The wiring that is the protective film defect detection means 3 is connected to a protective film defect detection wiring circuit provided in the substrate, and the signal of this circuit is connected to an electrode part different from the wiring that drives the heating resistor 7. And can communicate with a connection terminal with the main body. Then, a voltage of about 1 to 3 V is periodically applied to the wiring that is the protective film defect detection means 3 during non-printing of the liquid ejection apparatus main body. The current value flowing through the wiring that is the protective film loss detection means 3 with respect to this input voltage can be output through the protective film loss detection wiring circuit.

  At this time, when the defects of the protective films (the lower protective film 9 and the upper protective film 6) proceed from the portion exposed at the end of the supply port 11 and the ink touches the protective film defect detection means 3, current leakage occurs. Will occur. Then, it is possible to detect abnormalities of the head on the liquid ejection device main body side based on changes in the current value output from the protective film loss detection wiring circuit, and to control the user to stop using or forcibly disable printing. It becomes.

(Substrate manufacturing method)
A basic substrate manufacturing process according to this embodiment will be described. An Si substrate or an Si substrate in which an IC for driving is already formed is used. First, the heat storage layer 2 formed by thermal oxidation or the like is formed on the substrate 1. Further, after the interlayer insulating layer 4 was formed by the CVD method or the like, the lower wiring 5 made of Al, Cu, Al—Si, Al—Cu or the like was formed thereon by the sputtering method. Next, a wiring pattern was formed using a photolithography method, and etching was performed using a reactive ion etching method or the like to complete the lower wiring 5. A lower protective film 6 made of SiO 2 or the like is formed thereon so as to cover at least the lower wiring 5 by sputtering or plasma CVD. Next, a through hole pattern is formed in the lower protective film 6 by a photolithography method or the like, and the insulating film is etched by a dry etching method or the like to form a through hole portion and a wire bonding pad hole portion. Next, the heating resistor 7 made of TaN, TaSiN or the like and the individual electrode wiring layer 8 made of Al, Cu, Al—Cu, Al—Si or the like are formed by reactive sputtering. Next, a wiring pattern is formed using a photolithographic method, and etching is continuously performed with Al and TaN by a reactive ion etching method or the like. Again, Al is removed by wet etching in order to expose the heat-generating portion again by photolithography. This part becomes a heating resistor. Next, an upper protective film 9 is formed of SiN as a protective film by plasma CVD. Next, a Ta film was formed as a cavitation resistant film 10 by a sputtering method.

  As described above, the example in which the individual electrode wiring layer is provided on the heating resistor has been described. However, the individual electrode wiring layer may be formed below the heating resistor.

(Detailed explanation regarding protective film and protective film loss detection means)
As shown in FIG. 1, the protective film includes an upper protective film 9 made of a Si compound such as SiN and a lower protective film 6 made of a Si compound such as SiO. The upper protective film 9 mainly serves as an interlayer insulating film, the lower protective film 6 mainly serves as a heat storage layer, and the upper protective film 9 has a thickness of 0.2 to 0.8 μm. 6 is in the range of 0.6-2 μm.

  Here, in this embodiment, the protective film defect detecting means 3 is formed before the lower protective film 6 is formed. Any one of Al, Au, Cu, and Si that is not used as the wiring lower wiring 5 for driving the heating resistor 7 as the protective film defect detection means 3 in the region between the supply port 11 and the lower wiring 5 in the planar direction. Alternatively, a pattern made of an alloy thereof or the like is formed.

  The wiring that is the protective film defect detection means 3 is connected to a protective film defect detection wiring circuit provided in the substrate, and the signal of this circuit is connected to an electrode part different from the wiring that drives the heating resistor 7. Is done. And it is the structure connected with the terminal which can output an electrical output value to the main body mounted through this protective film defect | deletion detection wiring circuit with respect to input voltage.

  As a result, even if the lower protective film 9 and the upper protective film 6 are lost from the portion in contact with the ink in the cross section of the supply port 11, current leakage occurs when the ink touches the protective film loss detecting means 3. Occur. Then, it is possible to detect abnormalities of the head on the liquid ejection device main body side based on changes in the current value output from the protective film loss detection wiring circuit, and to control the user to stop using or forcibly disable printing. It becomes.

(First embodiment)
FIG. 1 is a schematic cross-sectional view for clearly illustrating the substrate film configuration of the liquid discharge head substrate according to the first embodiment of the present invention. FIG. 2 is a schematic view seen from the upper surface of the substrate so that the positional configuration of the heating resistor 7 and the protective film loss detecting means 3 in this embodiment can be understood. The wiring pattern of the protective film loss detecting means 3 is a pattern arranged in a straight line in the parallel direction in a row of the heating resistors 7 arranged in parallel in the longitudinal direction of the supply port.

  As shown in FIG. 1, 6500 熱 of a heat storage layer 2 made of a thermal oxide film was formed on a Si substrate 1 having a thickness of 625 μm. On top of that, an interlayer insulating film 4 made of SiO 2 or the like is formed by a CVD method or the like.

  On this, the lower wiring 5 connected to the heat generating resistor by Al was formed by sputtering or the like. Next, a wiring pattern was formed using a photolithography method, and etching was performed using a reactive ion etching method or the like to complete the lower wiring 5.

  At this time, a wiring pattern for the protective film defect detecting means 3 that is electrically independent from the lower wiring 5 is formed as the protective film defect detecting means 3 at the same time as the lower wiring 5 is formed. At this time, the protective film defect detecting means is located in the layer in the protective film corresponding to the gap between the supply port end of the wiring (lower wiring or upper wiring) and the supply port when viewed from the upper surface of the substrate. To be provided.

  On top of this, 15000 mm of a lower protective film 6 made of SiO 2 or the like is formed by plasma CVD or the like. Next, a through hole pattern is formed in the lower protective film 6 by a photolithography method or the like, and the insulating film is etched by a dry etching method or the like to form a through hole portion and a wire bonding pad hole portion. Next, 500 を of the heating resistor 7 made of TaSiN and the individual electrode wiring layer 8 made of Al are formed by reactive sputtering or the like. Next, a wiring pattern is formed using a photolithography method or the like, and etching is continuously performed with Al and TaN by a reactive ion etching method or the like. Again, Al is removed by wet etching in order to expose the heat-generating portion again by photolithography or the like. This part becomes a heating resistor. Next, an upper protective film 9 is formed as a protective film with a thickness of 3000 nm by SiN by plasma CVD. Next, 2300 mm of Ta film was formed as a cavitation resistant film 10 by sputtering.

  On the substrate 1 completed as described above, ink is supplied from the supply port and a chamber formed on each heating resistor and a nozzle member (not shown) for guiding the ink to each ink discharge port are formed. And an adhesion improving layer 12 for improving the adhesion of the nozzle member.

  In order to secure the adhesion between the nozzle member and the substrate 1 for the ink, the adhesion improving layer 12 is preferably made of a material having low solubility in ink.

  In the present embodiment, as shown in FIG. 2, the wiring pattern of the protective film loss detecting means 3 is a pattern arranged in a straight line in a parallel direction in a row of a plurality of heating resistors 7 arranged in parallel in the longitudinal direction of the supply port. It has become. As a result, it is possible to detect a defect in the protective film between all the heating resistors 7 and the supply ports 11.

  Printing was performed in a printing environment where the substrate temperature was about 60 ° C. by mounting the ink in the liquid ejecting apparatus equipped with the recording head shown in the present embodiment. Furthermore, it was left at room temperature for 5 years. Then, since a defect of the protective film occurs and the ink touches the protective film defect detection means 3, it becomes possible to detect a change in the current value output from the protective film defect detection wiring circuit on the liquid ejection device side, and in an abnormal state Reliability can be maintained without using a liquid ejection device.

(Comparative example)
FIG. 7 shows a case where a conventional substrate and an adhesion improving layer are formed. FIG. 13 is a schematic diagram in the case where the upper protective film 9 and the lower protective film 6 are etched with respect to the case where the conventional substrate and the adhesion improving layer are formed. Here, the shaded portion in FIG. 13 shows the state after the upper protective film 9 and the lower protective film 6 are etched.

  In this case, if the upper protective film 9 and the lower protective film 6 to be protected are lost, and if the defects further spread to the interlayer insulating film 4, the ink enters the individual electrode wiring layer 8 and an electrical short circuit occurs. May occur and the liquid discharge head may not operate normally. Further, at this time, there is a possibility that the liquid discharge liquid discharge apparatus main body may be affected by the short circuit affecting the electrical connection portion between the main body and the head.

  In addition, the liquid discharge head used in the thermal type liquid discharge liquid discharge apparatus using the heating resistor has an original function by reducing the heat capacity of the entire substrate without breaking the head and the liquid discharge apparatus main body. There is a high possibility that it will not be demonstrated.

  In FIG. 8, by providing the adhesion improving layer 12 on the upper surface portion where the ink contacts the protective film, the contact area between the ink and the upper protective film 9 and the lower protective film 6 is reduced as much as possible, and the loss of the ink to the substrate 1 is minimized. A limited configuration is shown, and this configuration is the basic form of the present invention.

  However, even in the configuration shown in FIG. 8, it is difficult to prevent the upper protective film 9 and the lower protective film 6 in the cross section of the supply port 11 from touching ink in the normal supply port and head forming process. is there. It is possible that the upper protective film 9 and the lower protective film 6 exposed in the cross section of the supply port portion 11 are etched over time, and the defect finally spreads to the interlayer insulating film 4.

(Second Embodiment)
FIG. 3 is a schematic cross-sectional view for clearly illustrating the substrate film configuration of the liquid discharge head substrate according to the second embodiment of the present invention.

  In the first embodiment, the position in the substrate cross-sectional direction where the protective film defect detecting means 3 is provided is in the lower protective film 6 on the heat storage layer (thermal oxide film) 2. On the other hand, in the second embodiment, it is provided in the upper protective film 9 on the lower protective film 6.

  As compared with the first embodiment, it is possible to form a wiring pattern for the protective film defect detecting means 3 after forming the lower protective film 6. Accordingly, in the first embodiment, when only the upper protective film 6 is lost and the lower protective film 9 is not lost, it is possible to detect the loss of only the upper protective film 6.

(Third embodiment)
FIG. 4 is a schematic cross-sectional view for clearly illustrating the substrate film configuration of the liquid discharge head substrate according to the third embodiment of the present invention.

  In the first embodiment, the position in the substrate cross-sectional direction where the protective film defect detecting means 3 is provided is in the lower protective film 6 on the heat storage layer (thermal oxide film) 2. On the other hand, in the second embodiment, it is provided over both the lower protective film 6 and the upper protective film 9 to be laminated.

  This can be realized by adding a manufacturing process to the first embodiment. For example, a gap for providing a protective film defect detecting means may be patterned in the upper protective film and the lower protective film, and then the protective film defect detecting means may be created. Thereby, the surface area which can detect the defect | deletion of the upper protective film 9 and the lower protective film 6 becomes larger than 1st and 2nd embodiment, and there exists a merit which can improve reliability.

(Fourth embodiment)
FIG. 5 is a schematic view of the substrate for a liquid discharge head according to the fourth embodiment of the present invention as seen from above the substrate for clearly illustrating the substrate film configuration.

  In the first embodiment, the wiring pattern of the protective film loss detecting means 3 is a pattern arranged in a straight line in the parallel direction in a row of the heating resistors 7 arranged in parallel in the longitudinal direction of the supply port. . On the other hand, in the fourth embodiment, the wiring pattern of the protective film loss detecting means 3 is independent of each heating resistor 7 and each lower wiring 5 connected thereto. In this case, the detection means is arranged so that the wiring of the protective film defect detection means 3 surrounds all the heating resistors 7 and the wiring connected thereto. As a result, there is an advantage that highly reliable protection film abnormality detection and fine control based on detection data of the protection film abnormality site are possible.

(Fifth embodiment)
FIG. 6 is a schematic view seen from above the substrate for clearly illustrating the substrate film configuration of the liquid discharge head substrate according to the fifth embodiment of the present invention.

  In the fourth embodiment, the wiring pattern of the protective film defect detecting means 3 is the wiring pattern of the protective film defect detecting means 3 independent of each heating resistor and each lower wiring connected thereto. On the other hand, in the fifth embodiment, a wiring pattern of the protective film loss detecting means 3 is provided independently only for some of the heating resistors and each lower wiring connected thereto. For example, the protective film defect detection means may be provided every other heating resistor or every several heating resistors.

  In this case, the merit of enabling fine control based on the detection data of the abnormal portion of the protective film is achieved while the area ratio of the wiring occupied by the protective film defect detecting means 3 with respect to the entire substrate is smaller than in the fourth embodiment. is there.

It is the schematic cross section shown so that the board | substrate cross-sectional structure in 1st Embodiment might be understood. It is the schematic diagram seen from the board | substrate upper surface so that the position structure of the heating resistor and protective film defect | deletion detection means in 1st Embodiment may be understood. It is the schematic cross section shown so that the board | substrate cross-sectional structure in 2nd Embodiment might be understood. It is the schematic cross section shown so that the board | substrate cross-sectional structure in 3rd Embodiment might be understood. It is the schematic diagram seen from the board | substrate upper surface so that the position structure of the heating resistor in 4th Embodiment and a protective film defect | deletion detection means can be understood. It is the schematic diagram seen from the board | substrate upper surface so that the position structure of the heating resistor and protective film defect | deletion detection means in 5th Embodiment can be understood. It is the schematic cross section shown so that the position of the conventional board | substrate cross-sectional structure and the contact | adherence improvement layer might be understood. It is the schematic cross section shown so that the position of a board | substrate cross-sectional structure and the contact | adherence improvement layer might be understood. It is a schematic diagram explaining the general shape of a head. It is the schematic diagram seen from the board | substrate front explaining the board | substrate part of a head. It is a schematic diagram explaining a liquid discharge apparatus. It is a block diagram for performing control of the liquid discharge apparatus which can apply an embodiment. It is a schematic diagram for demonstrating the case where the subject of this invention arises in the schematic cross section of the conventional board | substrate cross-sectional structure and an adhesion improvement layer.

Explanation of symbols

1 Substrate (Si)
2 Thermal storage layer (thermal oxide film)
3 Protective film loss detection means 4 Interlayer insulating film 5 Lower wiring 6 Lower protective film (SiO)
7 Heating resistor 8 Individual electrode wiring 9 Upper protective film (SiN)
10 Anti-cavitation film (Ta)
11 Supply Port 12 Adhesion Improvement Layer 21 Recording Head

Claims (10)

Provided on the surface of the substrate are a plurality of heating resistors that generate energy used to discharge the liquid, wirings electrically connected to the heating resistors, and insulation that covers at least the wirings and a protective film, have a supply port for supplying the liquid to said surface of said substrate, Te plurality of heating resistors liquid discharge head substrate smell formed along the arrangement direction of,
A detection wiring used for detecting that a defect has occurred in the protective film is in contact with the protective film corresponding to a gap between the supply port side end of the wiring and the supply port, and the substrate A substrate for a liquid discharge head, which is continuously provided between the plurality of heating resistors and the supply port along the arrangement direction as viewed from a direction perpendicular to the surface . 2. The liquid discharge head substrate according to claim 1, wherein the detection wiring is provided at a position not overlapping with the plurality of heating resistors when viewed from the vertical direction. The detection wiring is a substrate for a liquid discharge head according to claim 1 or 2, characterized in that they are electrically independent from said heating resistor. The detection wiring, Al, Au, Cu, any of Si, or a substrate for a liquid discharge head according to any one of claims 1 to 3, wherein the alloys thereof. Substrate for a liquid discharge head according to any one of claims 1 to 4 wherein the sensing line may be disposed along the longitudinal direction of the supply port. The protective layer, a substrate for a liquid discharge head according to any one of claims 1 to 5, characterized in that formed by laminating a layer made of SiO or Rana Ru layer and SiN. The liquid discharge head substrate according to claim 6 , wherein the detection wiring is provided in at least one of the layer made of SiO and the layer made of SiN. The liquid discharge head substrate according to claim 7, wherein the detection wiring is provided across the layer made of SiO and the layer made of SiN. A substrate for a liquid discharge head according to any one of claims 1 to 8, a flow path capable supply of liquid from the supply port, the liquid discharge head having a discharge port for discharging the liquid. A head according to claim 9, through the wiring circuit connected to the sensing wire, the liquid discharge apparatus having a means for obtaining information of the detection wire.

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