JP2015199312A - Element substrate for liquid discharge head and liquid discharge head using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an element substrate for a head in which multiple energy generating parts share one discharge port, and each energy generating part achieves desired discharge performance.SOLUTION: The element substrate includes: first and second energy generating parts 23, 24 for generating energy for discharging liquid; first and second electric wiring layers 3, 4 electrically connected to the first and second energy generating parts respectively, for supplying electric power to the first and second energy generating parts; a discharge port forming member 10 provided with a discharge port 11 to be used by the first and second energy generating parts in common; and a substrate 1 having the first and second energy generating parts, the first and second electric wiring layers and the discharge port forming member. When viewed from a direction perpendicular to a surface of the substrate, a second area 26 surrounded by an outer peripheral edge of the second energy generating part 23 contains a first area 25 surrounded by an outer peripheral edge of the first energy generating part, and a center of gravity 23a of the second energy generating part is inside the first area 25.

Description

  The present invention relates to a liquid discharge head element substrate and a liquid discharge head using the same.

  An element substrate for a liquid discharge head mounted in an inkjet recording apparatus or the like has a plurality of discharge ports for discharging liquid and a plurality of energy generation elements for generating thermal energy for discharging liquid from the discharge port. ing. The energy generating element includes a heating resistor layer and an electric wiring layer for supplying electric power thereto. In order to ensure insulation between the liquid and the energy generating element, the heating resistor layer and the electric wiring layer are covered with an insulating layer made of an insulating material. The energy generating element generates thermal energy by the supplied electric power, and the liquid is rapidly heated by this thermal energy. The liquid will boil and form a foam. The liquid is discharged from the discharge port to the recording medium by the pressure accompanying the formation of the foam, and recording is performed.

  2. Description of the Related Art Conventionally, a technique for adjusting the droplet size of a liquid ejected from an ejection port is known for recording with excellent gradation. Patent Document 1 discloses a liquid discharge head element substrate by an edge shooter method. A plurality of energy generating units (heating elements) are arranged in parallel in one flow path, and one discharge port is provided at the tip of the flow path. Each energy generating unit heats the liquid with the supplied electric power and discharges the liquid from a common discharge port. Gradation recording is performed by controlling the timing of supplying power to each energy generator.

Japanese Examined Patent Publication No. 62-48585

  In the configuration described in Patent Document 1, since a plurality of energy generation units are arranged in parallel, the positional relationship between the foam generation position and the discharge port is different for each energy generation unit. Since the droplet size and the discharge timing are affected by the positional relationship between the foam generation position and the discharge port, it may be difficult to obtain a desired discharge performance.

  An object of the present invention is to provide an element substrate for a liquid discharge head in which a plurality of energy generation units share one discharge port, and each energy generation unit can easily obtain a desired discharge performance.

  The element substrate for a liquid discharge head according to the present invention is electrically connected to the first and second energy generation units that generate energy for discharging liquid, and the first and second energy generation units, respectively. First and second electric wiring layers for supplying electric power for generating energy to the first and second energy generating units, and an ejection port for ejecting liquid, the ejection port generating first and second energy A discharge port forming member provided in common on the surface, a substrate on which the first and second energy generating units, the first and second electric wiring layers, and the discharge port forming member are provided on the surface. doing. When viewed from the direction perpendicular to the surface of the substrate, the second region surrounded by the outer periphery of the second energy generation unit includes the first region surrounded by the outer periphery of the first energy generation unit, The center of gravity of the second energy generating unit is inside the first region.

  The first and second regions generally correspond to regions where foam is formed. When viewed from the direction perpendicular to the surface of the substrate, the second region includes the first region, and the center of gravity of the second energy generation unit is inside the first region. The center of gravity of the formed foam and the center of gravity of the foam formed by the second energy generating unit are close to each other. Therefore, no matter which energy generating part generates the foam, the positional relationship between the foam and the discharge port does not change greatly, and the discharge performance is stabilized. For this reason, it becomes easy for each energy generation part to obtain desired discharge performance.

  According to the present invention, it is possible to provide an element substrate for a liquid discharge head in which a plurality of energy generation units share one discharge port, and each energy generation unit can easily obtain a desired discharge performance.

It is a perspective view of the element substrate for liquid ejection heads of the present invention. It is a figure which shows the element substrate for liquid discharge heads of the 1st Embodiment of this invention. It is a figure which shows foaming and discharge of the droplet in the element substrate shown in FIG. It is a figure which shows the element substrate for liquid discharge heads of the 2nd Embodiment of this invention. FIG. 5 is a diagram showing foaming and droplet discharge in the element substrate shown in FIG. 4. FIG. 5 is a cross-sectional view showing a manufacturing process of the element substrate for a liquid discharge head shown in FIG. FIG. 5 is a cross-sectional view showing a manufacturing process of the element substrate for a liquid discharge head shown in FIG.

  The element substrate for a liquid discharge head of the present invention is used for a liquid discharge head of a printer or the like that discharges a liquid such as ink onto a recording medium and records an image. Hereinafter, some embodiments of the liquid discharge head will be described by taking an inkjet head as an example.

  FIG. 1 is a perspective view of a liquid discharge head element substrate (hereinafter referred to as an element substrate 100) common to various embodiments of the present invention. The element substrate 100 includes a substrate made of silicon (hereinafter referred to as a silicon substrate 1) and a discharge port forming member 10 provided on the surface thereof. The top plate 10a of the discharge port forming member 10 includes a plurality of discharge ports 11 that discharge liquid. A foaming chamber 12 for foaming the liquid is formed inside the discharge port forming member 10. An energy generating element 14 is formed on the silicon substrate 1 inside the foaming chamber 12. In the silicon substrate 1, a supply port 13 that penetrates the silicon substrate 1 and communicates with the foaming chamber 12 and supplies liquid to the foaming chamber 12 is formed. Hereinafter, each embodiment will be described in more detail.

(First embodiment)
FIG. 2A shows a cross-sectional view of the element substrate 100 taken along line AA in FIGS. 1 and 2B. A first insulating layer 5 is formed on the silicon substrate 1, and a first electric wiring layer 3 is formed on the first insulating layer 5. The first electric wiring layer 3 is divided into a first portion 3 a and a second portion 3 b by a heating resistor layer 2 described later. When the first electric wiring layer 3 is formed, the first insulating layer 5 The center part is exposed. A second insulating layer 6 is formed on the first electric wiring layer 3. Similarly, the second insulating layer 6 is divided into a first portion 6 a and a second portion 6 b by the heating resistor layer 2, and the central portion of the first insulating layer 5 is formed when the second insulating layer 6 is formed. Is exposed.

  On the first insulating layer 5 and the second insulating layer 6, the heating resistor layer 2 that generates heat when power is supplied is formed. The heating resistor layer 2 constitutes a part of the energy generating element 14. The heating resistor layer 2 has a flat portion 2a and a recess 2b connected to the flat portion 2a and closer to the substrate 1 than the flat portion 2a. The first electric wiring layer 3 is formed in the recess 2b of the heating resistor layer 2. It is connected. The first electrical wiring layer 3 and the bottom layer 2c of the recess 2b of the heating resistor layer 2 are formed on the same laminated surface S1. A second electrical wiring layer 4 is formed on the heating resistor layer 2. The second electrical wiring layer 4 is connected to the upper surface of the flat portion 2 a of the heating resistor layer 2. Therefore, the first electric wiring layer 3 and the second electric wiring layer 4 extend on different laminated surfaces S1 and S2. The second electric wiring layer 4 is divided into a first portion 4a and a second portion 4b, and when the second electric wiring layer 4 is formed, the concave portion 2b of the heating resistor layer 2 and a part of the flat portion 2a. Is exposed.

  A protective film 7 is formed on the second electrical wiring layer 4 and the heating resistor layer 2. On the protective film 7, a cavitation-resistant film 8 is formed over a wider range than the foaming section where liquid foaming occurs due to the heating resistor layer 2. A discharge port forming member 10 having a discharge port 11 is formed above the protective film 7 and the anti-cavitation film 8. A space between the protective film 7 and the anti-cavitation film 8 and the top plate 10 a of the discharge port forming member 10 is a foaming chamber 12 in which liquid is foamed by the heat generated by the heating resistor layer 2.

  As described above, the first electric wiring layer 3 and the second electric wiring layer 4 are connected to the heating resistor layer 2. The first electric wiring layer 3 and the second electric wiring layer 4 are independent from each other, and can supply power to the heating resistor layer 2 individually. When power is supplied from the first electric wiring layer 3, the section of the heating resistor layer 2 sandwiched between the ends of the two portions 3a and 3b of the first electric wiring layer 3, in this embodiment, the recess 2b. The section between the two ends functions as a resistor. In this specification, this section is referred to as a first section 21. In other words, the two portions 3 a and 3 b of the first electrical wiring layer 3 are connected to both ends 21 a and 21 b of the first section 21 of the heating resistor layer 2, respectively. When power is supplied from the second electrical wiring layer 4, the section of the heating resistor layer 2 sandwiched between the ends of the two portions 4a and 4b of the second electrical wiring layer 4 functions as a resistor. In this specification, this section is referred to as a second section 22. In other words, the two portions 4 a and 4 b of the second electrical wiring layer 4 are connected to both ends 22 a and 22 b of the second section 22 of the heating resistor layer 2, respectively. Both ends 21a and 21b (connection portions to the first electric wiring layer 3) of the first section 21 of the heating resistor layer 2 are connected to both ends 22a and 22b (second electric wiring layer 4 and the second electric wiring layer 4). ) On a different laminated surface.

  2B is a plan view of the element substrate 100 as viewed from the line BB in FIG. 2A, and FIG. 2C is an exploded perspective view of the element substrate 100. FIG. 2B and 2C, the protective film 7 and the anti-cavitation film 8 are not shown. The energy generating element 14 includes a first energy generating unit 23 corresponding to the first section 21 and a second energy generating section 24 corresponding to the second section 22. The first and second energy generators 23 and 24 each generate energy for discharging a liquid. The first and second electric wiring layers 3 and 4 are electrically connected to the first and second energy generation units 23 and 24, respectively, and cause the first and second energy generation units 23 and 24 to discharge liquid. Supply power to generate energy for. Thus, in this embodiment, the 1st and 2nd energy generation parts 23 and 24 are implement | achieved by making the heat_generation | fever area of the one heat generating resistor layer 2 differ. The discharge port 11 and the discharge port forming member 10 in which the discharge port 11 is formed are provided in common to the first and second energy generation units 23 and 24.

  The first energy generation unit 23 is smaller than the second energy generation unit 24. That is, the first energy generation unit 23 is a part of the second energy generation unit 24 in the width direction W of the heating resistor layer 2 and the extending direction L orthogonal to the width direction W, and the surface of the substrate 1 It is included in the second energy generator 24 as viewed from the vertical direction D.

  When viewed from a direction D perpendicular to the surface of the substrate 1, the center of gravity 23 a of the first energy generation unit 23 and the center of gravity 24 a of the second energy generation unit 24 coincide. The “direction D perpendicular to the substrate 1” means a direction perpendicular to the surface of the substrate 1, that is, the surface 1 a facing the discharge port forming member 10 of the substrate 1. The center of gravity is synonymous with the centroids of the first and second energy generators 23 and 24 when viewed from the direction D perpendicular to the surface 1a of the substrate 1. In other words, the center of gravity is the centroid of the figure on the surface obtained by projecting the first and second energy generators 23 and 24 onto the surface parallel to the substrate 1 in the direction D perpendicular to the surface 1a of the substrate 1. It is. In the present embodiment, since the first and second energy generators 23 and 24 are both rectangular, the centroids 23a and 24a both coincide with the center of the rectangle. In the present embodiment, the centroids 23 a and 24 a of the first and second energy generators 23 and 24 are on the central axis 11 a of the discharge port 11.

  The centroids 23a and 24a of the first and second energy generators 23 and 24 preferably coincide with each other, but may not coincide completely. When viewed from the direction D perpendicular to the surface 1 a of the substrate 1, a region surrounded by the outer peripheral edge of the first energy generating unit 23 is defined as a first region 25, and is surrounded by the outer peripheral edge of the second energy generating unit 24. This area is referred to as a second area 26. In the present embodiment, the first and second regions 25, 26 coincide with the first and second energy generation units 23, 24, respectively, and the second region 26 includes the first region 25. The center of gravity 24a of the second energy generating unit 24 only needs to be inside the first region 25 when viewed from the direction D perpendicular to the surface 1a of the substrate 1.

  The first and second regions 25 and 26 generally correspond to the foam generation regions generated in the first and second energy generation units 23 and 24, respectively (see FIG. 3). Therefore, in the present embodiment, the foam is generated mainly around the inside of the first region 25 regardless of which of the first and second energy generators 23 and 24 generates heat. That is, the positional relationship between the foam generation position and the discharge port 11 does not vary greatly depending on which of the first and second energy generation units 23 and 24 generates heat. The pattern of foaming and discharging only changes depending on the amount of heat generated by the first and second energy generating units 23 and 24. Therefore, the discharge timing, the discharge direction, and the like do not change greatly depending on which of the first and second energy generation units 23 and 24 generates heat. This effect is particularly noticeable when the centroids 23a, 24a of the first and second energy generating parts 23, 24 coincide.

  As shown in FIG. 2 (d), the first energy generation unit 23 coincides with the second energy generation unit 24 in the width direction W of the heating resistor layer 2, and the extending direction L of the heating resistor layer 2. May be part of the second energy generator 24.

  FIG. 3 conceptually shows foaming and liquid discharge in the present embodiment. FIG. 3A shows foaming and liquid discharge when power is supplied to the first electrical wiring layer 3, and FIG. 3B shows foaming and liquid discharge when power is supplied to the second electrical wiring layer 4. . As shown in FIG. 3A, when power is supplied to the first electrical wiring layer 3 connected to the recess 2b of the heating resistor layer 2, the first energy generating unit 23 generates heat, and the first energy is generated. A first foam 31 is generated in the vicinity of the generating portion 23. The first foam 31 applies pressure to the liquid in the vicinity of the discharge port 11, and discharges the first droplet 41 from the discharge port 11 by the pressure. As shown in FIG. 3B, when power is supplied to the second electrical wiring layer 4 connected to the flat portion 2a of the heating resistor layer 2, the second energy generating unit 24 generates heat, and the second A second foam 32 is generated in the vicinity of the energy generating unit 24. The second foam 32 applies pressure to the liquid in the vicinity of the discharge port 11, and causes the second droplet 42 to be discharged from the discharge port 11 by the pressure. When the second energy generator 24 generates heat, it is sufficient to supply power to the second section 22, and it is not necessary to supply power to the first section 21 at the same time. Therefore, when the first energy generating unit 23 is caused to generate heat, power is supplied only to the first electric wiring layer 3, and when the second energy generating unit 24 is caused to generate heat, only the second electric wiring layer 4 is supplied with electric power. It is desirable to supply

  Since the second energy generation unit 24 is wider than the first energy generation unit 23 and generates a large amount of heat, the second foam 32 is larger than the first foam 31 and the second droplet 42 is It is larger than the first droplet 41. That is, by supplying electric power to the first section 21 or the second section 22 of the heating resistor layer 2, foams of different sizes and different droplet sizes or droplet amounts can be obtained. Moreover, since the centroids 23a and 24a of the first energy generation unit 23 and the second energy generation unit 24 coincide with each other, the foam generation position and the discharge port 11 can be used regardless of which energy generation unit 23 or 24 is used. Are in the same positional relationship. For this reason, it is possible to suppress the influence on the discharge performance due to the difference in the generation position of the foam with respect to the discharge port 11, and it is possible to stably perform the variable control of the droplet discharge amount.

  Moreover, in this embodiment, since the 1st and 2nd energy generation parts 23 and 24 share the one heat generating resistor layer 2, the compact element substrate 100 is realizable. In addition, since the first energy generation unit 23 and the second energy generation unit 24 are located at different distances from the substrate 1, the first electric wiring layer 3 and the second electric wiring layer 4 are stacked differently. It can arrange | position to surface S1, S2. As a result, the first and second electric wiring layers 3 and 4 can be three-dimensionally arranged, and a more compact element substrate 100 can be realized. According to the present embodiment, in order to perform variable control of the ink discharge amount, it is not necessary to individually provide foaming chambers each having energy generating elements of different sizes.

  The second energy generation unit 24 communicates the second foam 32 generated by the second energy generation unit 24 to the outside of the discharge port 11 when the second droplet 42 is discharged from the discharge port 11. be able to. The first energy generation unit 23 does not allow the first foam 31 generated by the first energy generation unit 23 to communicate with the outside of the discharge port 11 when the first droplet 41 is discharged from the discharge port 11. Can be.

(Second Embodiment)
FIG. 4 shows a conceptual diagram of an element substrate 100 according to the second embodiment. 4A is a cross-sectional view of the element substrate 100 taken along line AA in FIGS. 1 and 4B, and FIG. 4B is a plan view of the element substrate 100 similar to FIG. 2B. FIG. 4C is an exploded perspective view of the element substrate 100. In FIGS. 4B and 4C, the protective film 7 and the anti-cavitation film 8 are not shown. The second embodiment is the same as the first embodiment except for the points described below.

  The energy generating element 14 includes first and second heating resistor layers 27 and 28 that generate heat by electric power. In the present embodiment, the first and second energy generators 23 and 24 are configured not as one heating resistor layer 2 but as a part of the first and second heating resistor layers 27 and 28, respectively. The first electric wiring layer 3 is divided into a first portion 3a and a second portion 3b, and the second electric wiring layer 4 is divided into a first portion 4a and a second portion 4b. The two portions 3a and 3b of the first electric wiring layer 3 are connected to both ends 23a and 23b of the first energy generation unit 23, respectively, and the two portions 4a and 4b of the second electric wiring layer 4 are The energy generator 24 is connected to both ends 24a and 24b, respectively.

  The second energy generation unit 24 is formed as a circular path having a start point 24a and an end point 24b that surround the first energy generation unit 23 and are separated from each other when viewed from the direction D perpendicular to the surface 1a of the substrate 1. ing. Specifically, the second energy generation unit 24 has a rectangular planar shape with a central portion serving as an opening 24c, and a part of one side is missing. The current can flow along the second energy generation unit 24 with one end portion sandwiching the deficient portion 24d as a start point 24a and the other end portion as an end point 24b. The two portions 4a and 4b of the second electric wiring layer 4 are connected to the start point 24a and the end point 24b. Unlike the first electric wiring layer 3, the two portions 4 a and 4 b of the second electric wiring layer 4 extend in parallel on the same side with respect to the second energy generation unit 24 with an interval 4 c therebetween. In the present embodiment, the first energy generating unit 23 is located in the opening 24 c of the second energy generating unit 24 when viewed from the direction D perpendicular to the surface 1 a of the substrate 1. However, the first energy generation unit 23 may overlap with the second energy generation unit 24 when viewed from the direction D perpendicular to the surface 1 a of the substrate 1. The second region 26 surrounded by the outer peripheral edge of the second energy generating unit 24 only needs to include the first region 25 surrounded by the outer peripheral edge of the first energy generating unit 23.

  Also in this embodiment, the center of gravity 23a of the first energy generating unit 23 and the center of gravity 24a of the second energy generating unit 24 are coincident with each other when viewed from the direction D perpendicular to the surface 1a of the substrate 1, but are completely coincident. It does not have to be. The center of gravity 24 a of the second energy generation unit 24 may be inside the first region 25 when viewed from the direction D perpendicular to the surface 1 a of the substrate 1.

  FIG. 5 conceptually shows foaming and liquid discharge in the present embodiment. FIG. 5A shows foaming and liquid discharge when power is supplied to the first electrical wiring layer 3, and FIG. 5B shows foaming and liquid discharge when power is supplied to the second electrical wiring layer 4. . As shown in FIG. 5A, when electric power is supplied to the first electrical wiring layer 3 connected to the first heating resistor layer 27, the first energy generator 23 generates heat, and the first energy is generated. A first foam 31 is generated in the vicinity of the generating portion 23. The first foam 31 applies pressure to the liquid in the vicinity of the discharge port 11, and discharges the first droplet 41 from the discharge port 11 by the pressure. When electric power is supplied to the second electrical wiring layer 4 connected to the second heating resistor layer 28 as shown in FIG. 5B, the second energy generating unit 24 generates heat, and the second energy generation A second foam 32 is generated in the vicinity of the portion 24. The second foam 32 applies pressure to the liquid in the vicinity of the discharge port 11, and causes the second droplet 42 to be discharged from the discharge port 11 by the pressure.

  Since the second energy generation unit 24 is wider than the first energy generation unit 23 and generates a large amount of heat, the second foam 32 is larger than the first foam 31 and the second droplet 42 is It is larger than the first droplet 41. Therefore, also in this embodiment, by supplying power to the first heating resistor layer 27 or the second heating resistor layer 28, different sizes of foams and different droplet sizes or droplet volumes can be obtained. It is done. Furthermore, when electric power is supplied simultaneously to the first heating resistor layer 27 and the second heating resistor layer 28, the total amount of heat generated by each is added to the droplets. Therefore, a larger foam obtained by combining the first foam 31 and the second foam 32 and a larger liquid droplet obtained by combining the first liquid droplet 41 and the second liquid droplet 42 are obtained. In the present embodiment, three types of droplet sizes can be obtained by selecting energization patterns for the first and second heating resistor layers 27 and 28. This enables finer gradation control and makes it easier to communicate the foam to the outside of the discharge port 11 when droplets are discharged from the discharge port 11.

  Also in this embodiment, since the center of gravity 23a, 24a of the 1st energy generation part 23 and the 2nd energy generation part 24 corresponds, the generation | occurrence | production position of a foam is used regardless of which energy generation part 23,24 is used. And the positional relationship between the discharge ports 11 are the same. For this reason, it is possible to suppress the influence on the discharge performance due to the difference in the generation position of the foam with respect to the discharge port 11. In addition, since the first and second electric wiring layers 3 and 4 can be arranged on different laminated surfaces, a compact element substrate 100 can be realized.

(First embodiment)
Details of the liquid discharge head element substrate according to the first embodiment of the present invention will be described in detail by way of examples. FIG. 6 is a cross-sectional view showing a manufacturing process of the liquid discharge head element substrate according to the first embodiment of the present invention.

First, as shown in FIG. 6A, the first insulating layer 5 is formed on the silicon substrate 1. Specifically, the first insulating layer 5 having a thickness of about 800 nm is formed by a CVD method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the first insulating layer 5 is etched by a reactive ion etching method using CF ₄ . Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The first insulating layer 5 can be formed using, for example, SiO, but is not limited as long as it is an insulating material. The first insulating layer 5 may be formed using SiN, for example.

Subsequently, as shown in FIG. 6B, the first electric wiring layer 3 is formed on the first insulating layer 5. Specifically, the first electric wiring layer 3 having a film thickness of about 500 nm is formed by a sputtering method. Thereafter, the first electric wiring layer 3 is selectively removed by Al wet etching using a mixed solution of acetic acid and phosphoric acid. Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The first electric wiring layer 3 can be formed using Al, but is not limited as long as the electric resistivity is 9 × 10 ⁻⁸ Ωm or less. The first electrical wiring layer 3 may be formed using, for example, gold, silver, copper or the like.

Subsequently, as shown in FIG. 6C, the second insulating layer 6 is formed on the first electric wiring layer 3 and selectively removed. Specifically, the second insulating layer 6 having a thickness of about 800 nm is formed by a CVD method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the second insulating layer 6 is etched by a reactive ion etching method using CF ₄ . Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The second insulating layer 6 can be formed using SiO, but is not limited as long as it is an insulating material. The second insulating layer 6 may be formed using SiN or the like, for example.

Subsequently, as shown in FIG. 6D, the first electric wiring layer 3 is selectively removed, and a part of the first insulating layer 5 is exposed. Specifically, the first electrical wiring layer 3 is selectively removed by Al wet etching using a mixed solution of acetic acid and phosphoric acid. Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping.

Subsequently, as illustrated in FIG. 6E, the heating resistor layer 2 including the flat portion 2 a and the concave portion 2 b is formed on the first insulating layer 5 and the second insulating layer 6. Specifically, the heating resistor layer 2 having a thickness of about 40 nm is formed by a sputtering method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the heating resistor layer 2 is etched by a reactive ion etching method using CF ₄ . Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The heating resistor layer 2 can be formed using TaSiN, for example.

Subsequently, as shown in FIG. 6F, the second electric wiring layer 4 is formed on the heating resistor layer 2. Specifically, the second electric wiring layer 4 having a thickness of about 500 nm is formed by a sputtering method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the second electric wiring layer 4 is etched by a reactive ion etching method in which BCI ₃ and CI ₂ gas are mixed. Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The second electrical wiring layer 4 can be formed using Al, but is not limited as long as the electrical resistivity is a material of 9 × 10 ⁻⁸ Ωm or less. The second electric wiring layer 4 may be formed using, for example, gold, silver, copper or the like.

Subsequently, as shown in FIG. 6G, a protective film 7 is formed on the heating resistor layer 2 and the second electric wiring layer 4. Specifically, the protective film 7 is formed by a CVD method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the protective film 7 is etched by a reactive ion etching method using CF ₄ . Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The protective film 7 can be formed using SiN, but is not limited as long as the material can protect the second electric wiring layer 4 and the heating resistor layer 2 from erosion by ink. The protective film 7 may be formed using, for example, SiO.

Subsequently, as shown in FIG. 6H, an anti-cavitation film 8 is formed on the protective film 7. Specifically, the anti-cavitation film 8 is formed by a sputtering method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the anti-cavitation film 8 is etched by a reactive ion etching method using CF ₄ . Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The anti-cavitation film 8 can be formed using Ta, for example.

  Subsequently, as shown in FIG. 6I, a mold material 9 is formed on the silicon substrate 1 on which the anti-cavitation film 8 is formed. Specifically, a moldable material 9 having a film thickness of about 15 μm is formed by applying a soluble positive photosensitive resin material by spin coating, and selectively exposing and developing. As the soluble positive photosensitive resin material, for example, ODUR (manufactured by Tokyo Ohka Kogyo Co., Ltd.) can be used.

  Subsequently, as illustrated in FIG. 6J, the discharge port forming member 10 including the discharge ports 11 is formed on the mold material 9 and the protective film 7. Specifically, a negative photosensitive resin material is applied by spin coating, the photosensitive resin material is selectively exposed and developed, and cured in an oven furnace at 140 ° C./60 min. Thereby, the discharge port forming member 10 having a film thickness of about 25 μm is formed. For example, an epoxy resin can be used as the negative photosensitive resin material. An example of the epoxy resin is EHPE-3150 (manufactured by Daicel Chemical Industries).

  Subsequently, as shown in FIG. 6 (k), the mold material 9 is removed to form the foaming chamber 12, and the discharge port forming member 10 is completed. Specifically, the mold material 9 is immersed in methyl lactate whose temperature is maintained at 40 ° C., and 200 KHz / 200 W ultrasonic waves are applied to the mold material 9. Thereby, the mold material 9 is eluted from the supply port 13 (see FIG. 1) and the discharge port 11 and removed. Through the above steps, the liquid discharge head element substrate 100 according to the first embodiment is completed.

(Second embodiment)
Details of the element substrate for a liquid discharge head according to the second embodiment of the present invention will be described in detail by way of examples. FIG. 7 is a cross-sectional view showing a process for manufacturing a liquid discharge head element substrate according to the second embodiment of the present invention.

  First, as shown in FIG. 7A, the first insulating layer 5 is formed on the silicon substrate 1. A first insulating layer 5 having a thickness of about 800 nm is formed by a CVD method. Although the 1st insulating layer 5 can be formed using SiO, it will not be limited if it is the material which has insulation. The first insulating layer 5 may be formed using SiN, for example.

Subsequently, as shown in FIG. 7B, a first heating resistor layer 27 is formed on the first insulating layer 5. Specifically, the first heating resistor layer 27 having a film thickness of about 40 nm is formed by a sputtering method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the first heating resistor layer 27 is etched into a predetermined shape by a reactive ion etching method in which BCI ₃ and CI ₂ gases are mixed. Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The first heating resistor layer 27 can be formed using TaSiN, for example.

Subsequently, as shown in FIG. 7C, the first electric wiring layer 3 is formed on the first heating resistor layer 27 and selectively removed. Specifically, the first electric wiring layer 3 is formed by a sputtering method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the first electric wiring layer 3 is selectively removed by Al wet etching using a mixed solution of acetic acid and phosphoric acid. Thereafter, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The first electrical wiring layer 3 can be formed using Al, but is not limited as long as the electrical resistivity is a material of 9 × 10 ⁻⁸ Ωm or less. The first electrical wiring layer 3 may be formed using, for example, gold, silver, copper or the like.

  Subsequently, as shown in FIG. 7D, the second insulating layer 6 is formed on the first electric wiring layer 3 and the first heating resistor layer 27. Specifically, the second insulating layer 6 having a thickness of about 800 nm is formed by a CVD method. The second insulating layer 6 can be formed using SiO, but is not limited as long as it is an insulating material. The second insulating layer 6 may be formed using SiN or the like, for example.

Subsequently, as shown in FIG. 7E, a second heating resistor layer 28 is formed on the second insulating layer 6 and selectively removed. Specifically, the second heating resistor layer 28 having a film thickness of about 40 nm is formed by sputtering. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the second heating resistor layer 28 is etched by a reactive ion etching method in which BCI ₃ and CI ₂ gases are mixed. Thereafter, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The second heating resistor layer 28 can be formed of the same material as the first heating resistor layer 27.

Subsequently, as shown in FIG. 7F, the second electric wiring layer 4 is formed on the second heating resistor layer 28. Specifically, the second electric wiring layer 4 having a thickness of about 500 nm is formed by a sputtering method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the second electric wiring layer 4 is selectively removed by Al wet etching using a mixed solution of acetic acid and phosphoric acid. Thereafter, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The second electrical wiring layer 4 can be formed using Al, but is not limited as long as the electrical resistivity is a material of 9 × 10 ⁻⁸ Ωm or less. The second electric wiring layer 4 may be formed using, for example, gold, silver, copper or the like.

Subsequently, as shown in FIG. 7G, the protective film 7 is formed on the second heating resistor layer 28 and the second electric wiring layer 4. Specifically, the protective film 7 having a thickness of about 300 nm is formed by a CVD method. Thereafter, a resist is selectively formed by photolithography so as to serve as an etching mask. Next, the protective film 7 is etched by a reactive ion etching method using CF ₄ . Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The protective film 7 can be formed using SiN, but is not limited as long as it is a material that can protect the second electric wiring layer 4 and the second heating resistor layer 28 from erosion by ink. The protective film 7 may be formed using, for example, SiO, SiC or the like.

Subsequently, as shown in FIG. 7H, an anti-cavitation film 8 is formed on the protective film 7. Specifically, the anti-cavitation film 8 is formed by a sputtering method. Thereafter, a resist is selectively formed by photolithography to create an etching mask. Next, the anti-cavitation film 8 is etched by a reactive ion etching method using CF ₄ . Subsequently, the resist and etching residue are removed by plasma ashing using O ₂ and wet stripping. The anti-cavitation film 8 can be formed using Ta, for example.

  Subsequently, the steps shown in FIGS. 7 (i), (j), and (k) are performed in the same steps as described in FIGS. 6 (i), (j), and (k) of the first embodiment. Through the above steps, the liquid discharge head element substrate 100 according to the second embodiment is completed.

DESCRIPTION OF SYMBOLS 1 Board | substrate 3, 4 1st and 2nd electric wiring layer 23, 24 1st and 2nd energy generation part 25, 26 1st and 2nd area | region 100 Element board | substrate for liquid discharge heads

Claims (14)

The first and second energy generation units that generate energy for discharging the liquid and the first and second energy generation units are electrically connected to the first and second energy generation units, respectively. The first and second electric wiring layers for supplying electric power for generating the energy, and the discharge port for discharging the liquid are provided in common to the first and second energy generation units. A discharge port forming member, a substrate on which the first and second energy generating portions, the first and second electrical wiring layers, and the discharge port forming member are provided,
When viewed from the direction perpendicular to the surface of the substrate, the second region surrounded by the outer peripheral edge of the second energy generating unit is the first region surrounded by the outer peripheral edge of the first energy generating unit. An element substrate for a liquid discharge head, which is contained and has a center of gravity of the second energy generation unit inside the first region.   2. The element substrate for a liquid discharge head according to claim 1, wherein a center of gravity of the second energy generation unit coincides with a center of gravity of the first energy generation unit when viewed from a direction perpendicular to the surface of the substrate.   Heat is generated by the electric power, and the first and second sections have heating resistor layers corresponding to the first and second energy generation units, respectively, and the first electric wiring layer is formed of the first section. 3. The liquid discharge head according to claim 1, wherein the liquid discharge head has two portions respectively connected to both ends, and the second electric wiring layer has two portions respectively connected to both ends of the second section. Element substrate.   The first electric wiring layer and the second electric wiring layer extend on different stacked surfaces, and both ends of the first section are on different stacked surfaces from the both ends of the second section. Item 4. The liquid discharge head element substrate according to Item 3.   The heating resistor layer has a flat portion and a concave portion connected to the flat portion and closer to the substrate than the flat portion, and the second electric wiring layer is connected to the flat portion, The liquid discharge head element substrate according to claim 4, wherein the electrical wiring layer is connected to the recess.   6. The liquid ejection according to claim 3, wherein the first energy generation unit is a part of the second energy generation unit in a width direction and a extending direction of the heating resistor layer. Element substrate for head.   The first energy generation unit coincides with the second energy generation unit in the width direction of the heating resistor layer, and is a part of the second energy generation unit in the extending direction of the heating resistor layer. The liquid discharge head element substrate according to claim 3, wherein the liquid discharge head element substrate is provided.   Heat is generated by the electric power, and each includes first and second heating resistor layers including the first and second energy generation units, and the first electrical wiring layer is formed of the first energy generation unit. 3. The liquid according to claim 1, further comprising two portions respectively connected to both ends, wherein the second electric wiring layer has two portions respectively connected to both ends of the second energy generation unit. Element substrate for discharge head.   9. The second energy generation unit is formed as a circuit path having a start point and an end point that surround the first energy generation unit and are separated from each other when viewed from a direction perpendicular to the surface of the substrate. The element substrate for liquid discharge heads described in 1.   10. The element substrate for a liquid discharge head according to claim 1, wherein the second energy generation unit is used to discharge a larger droplet than the first energy generation unit. 11.   The second energy generation unit causes the foam generated in the second energy generation unit to communicate with the outside of the discharge port when droplets are discharged from the discharge port, and the first energy generation unit 11. The element substrate for a liquid discharge head according to claim 10, wherein when a droplet is discharged from the discharge port, the foam generated in the first energy generation unit is not communicated with the outside of the discharge port. The first and second energy generation units that generate energy for discharging the liquid and the first and second energy generation units are electrically connected to the first and second energy generation units, respectively. The first and second electric wiring layers for supplying electric power for generating the energy, and the discharge port for discharging the liquid are provided in common to the first and second energy generation units. A discharge port forming member, and a substrate on which the first and second energy generating units, the first and second electric wiring layers, and the discharge port forming member are provided,
The first energy generation unit and the second energy generation unit are located at different distances from the substrate and are surrounded by an outer peripheral edge of the second energy generation unit when viewed from a direction perpendicular to the surface of the substrate. The second region is a liquid discharge head element substrate including a first region surrounded by an outer peripheral edge of the first energy generation unit.   The liquid discharge head element substrate according to claim 12, wherein a center of gravity of the second energy generation unit is in the first region when viewed from a direction perpendicular to the surface of the substrate.   A liquid discharge head comprising the liquid discharge head element substrate according to claim 1.