JP6168909B2 - Manufacturing method of substrate for liquid discharge head - Google Patents

Description

  The present invention relates to a method for manufacturing a substrate for a liquid discharge head.

  As disclosed in Patent Document 1, in a liquid discharge head substrate, a liquid supply port for supplying a liquid to be discharged is formed through the silicon substrate. According to the above document, the liquid supply port is formed by wet etching the silicon substrate after the etching resistant mask is formed on the back side of the substrate.

  Here, in the process before the process of forming the liquid supply port, if scratches occur on the etching start surface due to the transport mechanism of the apparatus, the etching proceeds irregularly starting from the scratches, and the liquid supply port becomes an abnormal shape. Sometimes formed.

  Therefore, Patent Document 2 proposes that the etching start surface including scratches is polished in advance to remove the scratches and form a clean surface.

Japanese Patent Laid-Open No. 10-181032 Japanese Patent Laid-Open No. 10-44438

  However, as shown in FIG. 2B, when the silicon substrate is polished by a machine or the like, a damaged layer 22 including crystal structure distortion may be formed on the polished surface. If a damaged layer is present on the etching start surface, as shown in FIG. 2D, when the liquid supply port is formed by etching, the etching proceeds irregularly in the damaged layer. As a result, the liquid supply port is formed in an unintended shape, which causes a decrease in yield.

  Accordingly, an object of the present invention is to provide a method for manufacturing a substrate for a liquid discharge head, which can form a liquid supply port with a high yield.

The present invention
A method for manufacturing a substrate for a liquid discharge head having a liquid supply port,
(1) preparing a substrate having an energy generating element that generates energy for discharging liquid on the first surface;
(2) performing a wet etching process on the substrate to form a non-penetrating opening in the first surface;
(3) The liquid supply port is formed by opening the non-penetrating opening in the second surface by thinning the substrate from the second surface that is the surface opposite to the first surface. And a process of
A method for manufacturing a substrate for a liquid discharge head, comprising:

  According to the configuration of the present invention, it is possible to provide a method for manufacturing a substrate for a liquid discharge head capable of forming a liquid supply port with a high yield.

It is a typical perspective view which shows the structural example of the board | substrate for liquid discharge heads obtained by this embodiment. It is process sectional drawing for demonstrating the subject which invention intends to solve. It is process sectional drawing for demonstrating the manufacturing method of this embodiment. It is process sectional drawing for demonstrating the manufacturing method of this embodiment. It is process sectional drawing for demonstrating the manufacturing method of this embodiment. 11 is a process cross-sectional view for explaining a process in the comparative example 1. FIG.

  The substrate for a liquid discharge head obtained by the present invention can be mounted on an apparatus such as a printer, a copying machine, a facsimile having a communication system, a word processor having a printer unit, or an industrial recording apparatus combined with various processing apparatuses. is there. By using this liquid discharge head device, recording can be performed on various recording media such as paper, thread, fiber, leather, metal, plastic, glass, wood, and ceramic. In the present invention, “recording” means not only giving an image having a meaning such as a character or a figure to a recording medium but also giving an image having no meaning such as a pattern. Further, the term “liquid” is to be interpreted widely, and is applied to a recording medium to form an image, a pattern, a pattern, or the like, process the recording medium, or process ink or recording medium. It shall refer to the liquid provided. Here, as the treatment of the ink or the recording medium, for example, the fixing property is improved by coagulation or insolubilization of the coloring material in the ink applied to the recording medium, the recording quality or coloring property is improved, and the image durability is improved. Say that.

  In the following description, as an application example of the present invention, an inkjet recording head substrate will be described as a main example as a liquid discharge head substrate, but the scope of the present invention is not limited thereto. Absent. In addition to the inkjet recording head substrate, the liquid ejection head substrate can be applied to a manufacturing method of a liquid ejection head substrate for biochip manufacturing and electronic circuit printing. Other examples of the liquid discharge head substrate include a color filter manufacturing application.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic perspective view illustrating a configuration example of a liquid discharge head substrate according to the present embodiment.

  As shown in FIG. 1, the substrate for a liquid discharge head of this embodiment has a substrate 1 on which energy generating elements 5 are formed in two rows at a predetermined pitch. The energy generating element is formed on the substrate and may be formed so as to be in contact with the substrate. Further, the liquid flow path 18 may be formed to be in an airborne state, that is, may be suspended in the air with respect to the substrate 1. The substrate 1 is, for example, a silicon substrate. On the first surface of the substrate 1 (the upper surface in FIG. 1), a flow path forming member 15 is disposed. The flow path forming member 15 forms a discharge port 16 and a liquid flow path 18 communicating with the discharge port. The discharge port 16 is opened above the energy generating element 5. Moreover, the flow path forming member can be formed of a resin, for example. Further, a liquid supply port 17 for supplying a liquid such as ink to the liquid flow path 18 is formed in the substrate 1. The liquid supply port 17 is open to the first surface of the substrate 1 and the second surface (the lower surface in FIG. 1) which is the surface opposite to the first surface. Further, the liquid supply port 17 is formed along the column direction of the discharge ports so as to open between two columns of the energy generating elements 5 by anisotropic etching. In this liquid discharge head substrate, the liquid flow path is filled with the liquid via the liquid supply port 17, and the liquid is discharged from the discharge port 16 by applying the pressure generated by the energy generating element 5 to the filled liquid. The Recording is performed by the discharged liquid adhering to the recording medium.

  In the present embodiment, the liquid supply port 17 is formed as follows, for example. First, an introduction hole for introducing an etching solution is formed on the first surface of the substrate, and then a wet etching process is performed on the substrate to form a non-penetrating opening on the first surface. Thereafter, the substrate is thinned by polishing or the like from the second surface side, which is the surface opposite to the first surface, thereby penetrating the non-penetrating opening into the second surface to form a liquid supply port.

  After the wet etching process, the flow path forming member 15 that forms the discharge port 16 and the liquid flow path 18 may be formed. The wet etching treatment is preferably performed from the first surface side, but the etching may proceed from the second surface.

  According to the configuration of the present invention, even if a damaged layer exists on the back surface of the substrate, the liquid supply port can be formed without exposing the damaged layer to the etching solution. Therefore, the liquid discharge head substrate substrate can be manufactured with a high yield.

  The wet etching process is preferably crystal anisotropic etching. In addition, since the liquid supply port is surrounded by the (111) plane, that is, the liquid supply port is configured by the (111) plane, the etching time can be easily controlled, and silicon or the like with respect to the alkaline liquid can be used. Elution of substrate components can be reduced.

  Further, in this embodiment, when a non-penetrating groove (for example, a dicing groove) is formed on the first surface before the step of thinning the substrate and the substrate is thinned to pass through the non-penetrating opening. In addition, the substrate can be divided by penetrating a non-penetrating groove through the second surface. Thereby, chipping at the time of division can be reduced.

  Embodiments of the present invention will be described below.

(Embodiment)
FIG. 3 is a sectional process diagram for explaining the present embodiment.

  First, as shown in FIG. 3A, a substrate 101 having an energy generating element 103 formed on a first surface is prepared. A sacrificial layer 102 is formed on the first surface of the substrate 101 and between the two rows of the energy generating elements 103. A protective layer 104 is formed on the energy generating element 103 and the substrate 101. A seed layer 105 is formed on the protective layer 104.

  The sacrificial layer is formed for the purpose of controlling the opening size on the first surface of the substrate during wet etching.

  Next, as shown in FIG. 3B, a non-penetrating introduction hole 106 for introducing an etching solution used for a wet etching process in a later step is formed in the substrate 101.

  The introduction hole can be provided so as to penetrate the sacrificial layer. The shape of the introduction hole is not particularly limited, but may be a groove shape, for example. The introduction hole can be formed using a laser, for example.

  Next, as shown in FIG. 3C, the substrate is wet-etched to form a non-penetrating opening 107 in the substrate. The wet etching treatment is preferably performed from the first surface side, but the etching may proceed from the second surface. That is, wet etching may be performed after protecting the second surface, or wet etching may be performed without protecting the second surface, and in addition to etching from the first surface, Etching may be advanced.

  The wet etching process is, for example, crystal anisotropic etching. Moreover, as an etchant used for the wet etching process, for example, TMAH (tetramethylammonium hydroxide), KOH (potassium hydroxide), NaOH (sodium hydroxide), or the like can be used.

  The sacrificial layer 102 is removed by wet etching.

  Next, as shown in FIG. 3D, a part of the seed layer 105 is removed in accordance with the opening dimension of the non-penetrating opening.

  For example, the seed layer 105 can be removed by dry etching after forming a mask on the seed layer using a photolithography technique.

  Next, as shown in FIG. 3E, a flow path forming member 108 that forms a discharge port for discharging liquid and a liquid flow channel communicating with the discharge port is formed on the first surface.

  The material of the flow path forming member is not particularly limited, and examples thereof include a resin, a metal, or an inorganic material. Examples of the resin include a photosensitive resin such as an epoxy resin. An example of the metal is a nickel plate. Examples of the inorganic material include SiN and SiC.

  Next, as shown in FIG. 3 (f), the substrate 101 is thinned from the second surface, which is the surface opposite to the first surface, and the non-penetrating opening 107 is opened at the second surface, so that the liquid Form a supply port.

  Examples of the method of thinning the substrate from the second surface include chemical mechanical polishing (CMP), back grinding, dry polishing, poly grinding and the like.

  When polishing the substrate, the opening size of the second surface of the liquid supply port can be controlled by adjusting the polishing amount.

  Next, as shown in FIG. 3G, the substrate is cut into chips to complete a liquid discharge head substrate.

  The step (e) of forming the flow path forming member may be formed at any timing as long as it is after the step of forming the non-penetrating opening and before the step of dividing the substrate. In the embodiment, the above steps may be included at least once, and the same steps may be used twice. This embodiment is preferable to simplify the process.

[Example]
Hereinafter, although it demonstrates more concretely using an Example, this invention is not limited by the following Example.

Example 1
Example 1 will be described with reference to FIG.

  As shown in FIG. 3A, a plurality of energy generating elements 103 are arranged on the first surface (the lower surface in Table 3) of the silicon substrate 101. A sacrificial layer 102 is formed between the two rows of energy generating elements 103 on the first surface of the silicon substrate. A protective layer 104 is formed on the energy generating element 103 and the silicon substrate 101. A seed layer 105 is formed on the protective layer 104. TaSiN was used as the energy generating element 103, SiO was used as the protective layer, gold was used as the seed layer, and aluminum was used as the sacrificial layer.

  Next, as shown in FIG. 3B, the introduction hole 106 was formed from the first surface side of the silicon substrate. The introduction hole 106 was formed so as to penetrate the sacrificial layer 102 from above the seed layer 105 and stay in the silicon substrate. The introduction holes were formed in a row along the row direction of the energy generating elements. The introduction hole was formed using a laser.

  Here, by forming the introduction hole, the degree of freedom in designing the opening size and depth of the liquid supply port on the first surface of the silicon substrate can be expanded. For example, by changing the processing depth of the groove-shaped introduction hole, the depth of the liquid supply port can be changed without changing the opening width of the liquid supply port.

  Next, as shown in FIG. 3C, the silicon substrate was wet-etched from the first surface side to form a non-penetrating opening 107 on the first surface of the substrate.

  The depth of the introduction hole is not required to penetrate the silicon substrate. However, when the etching resistant layer is not provided on the second surface of the silicon substrate, the etching also proceeds from the second surface. In this case, it is important to determine the depth of the introduction hole in consideration of etching from the second surface. That is, the sum of the depth of the introduction hole and the etching amount from the second surface of the silicon substrate is set to be smaller than the substrate thickness.

  In this embodiment, since the silicon substrate 101 is a (100) substrate, the substrate thickness is 725 μm, the etching solution is TMAH (22 wt%), and the etching temperature is 80 ° C., the etching rate on the (100) plane is 0.5 μm / min. It becomes. The etching amount from the second surface is the product of the etching time and the (100) surface rate. In this example, as shown in FIG. 3C, the crystal anisotropic etching was performed until the shape surrounded by the (111) plane was obtained. Etching at this time extends the groove-shaped introduction hole to the left and right (110) plane direction to the intersection where the top of the introduction hole and the (111) plane form an angle of 54.7 ° from the first surface opening, respectively. Progressed. The lateral width of the non-penetrating opening 107 is 333 μm when the width of the sacrificial layer is 100 μm and the depth of the groove-like introduction hole is 400 μm by geometric calculation, and the (110) plane rate is 1.00 μm / min. As a result, the etching time was 167 min. Therefore, the etching amount from the second surface is 84 μm, and the total of the groove-shaped introduction holes 400 μm is the substrate thickness of 725 μm or less, which satisfies the condition.

  Next, as shown in FIG. 3D, the seed layer in the portion located in the opening of the non-penetrating opening 107 was removed.

  Next, as shown in FIG. 3E, a flow path forming member was formed on the first surface of the substrate.

  In this embodiment, the flow path forming member is formed before the step of thinning the substrate, but after the step of forming the non-penetrating opening and before the step of dividing the substrate into chips. If so, the flow path forming member may be formed at any timing.

  Next, as shown in FIG. 3F, the flow path forming member was protected, and a dicing tape was provided on the first surface side of the silicon substrate for dicing.

  Then, the silicon substrate was thinned from the second surface of the silicon substrate by polishing, thereby opening the non-penetrating opening on the second surface and forming a liquid supply port.

  The amount of polishing is not particularly limited, but for example, if the thickness of the silicon substrate is made equal to or less than the processing depth of the introduction hole, the non-penetrating opening is opened on the second surface. It may be further thinned, and the opening size on the second surface of the liquid supply port can be adjusted by the amount of polishing. In this example, in order to set the final substrate thickness to 200 μm, the polishing amount was set to 441 μm in consideration of the etching amount of 84 μm from the second surface.

  Finally, the substrate was divided for each chip to manufacture a liquid discharge head substrate.

  According to this embodiment, a liquid supply port can be formed without exposing a damaged layer generated by polishing a silicon substrate to an etching solution, and a method for manufacturing a substrate for a liquid discharge head with a high yield can be provided.

(Example 2)
Example 2 will be described with reference to FIGS. 4 (e-2) to (h-2).

  In Example 2, steps (a) to (d) in Example 1 are the same step, and the steps are different after step (e) in Example 1. Therefore, FIG. 4 shows (e-2) to (h-2) corresponding to step (e) and subsequent steps in the first embodiment.

  First, the substrate 101 in which the non-penetrating opening 107 was formed was prepared by steps (a) to (d) of Example 1.

  Next, as shown in FIG. 4E-2, dicing grooves not penetrating from the first surface of the silicon substrate were formed at positions where the substrate was to be divided.

  At this time, the depth of the non-penetrating dicing groove may be equal to or greater than the final substrate thickness after thinning. The depth of the non-penetrating dicing groove is preferably not less than the final substrate thickness after thinning and not more than the depth of the non-penetrating opening. In this example, since the substrate thickness after thinning was set to 200 μm, the non-penetrating dicing grooves were set to a depth of 250 μm.

  Next, as shown in FIG. 4F-2, a flow path forming member was formed on the first surface of the silicon substrate.

  The timing for forming the flow path forming member is not particularly limited, but in the present embodiment, it is preferably after the step of forming the non-penetrating opening and before the step of thinning the substrate. .

  Next, as shown in FIG. 4 (g-2), the silicon substrate is thinned by polishing from the second surface of the silicon substrate to penetrate the non-penetrating dicing grooves to be divided into chips, and the non-penetrating Was opened on the second surface.

  In this example, the polishing amount was 441 μm in order to make the substrate thickness after thinning 200 μm as in Example 1.

  According to this embodiment, the substrate can be divided by penetrating the non-penetrating dicing grooves in the substrate thinning step. Thereby, chipping can be reduced, and a method for manufacturing a substrate for a liquid discharge head with a high yield can be provided.

(Example 3)
Example 3 will be described with reference to FIGS. 5 (a-3) to (c-3).

  In Example 3, steps (e) to (g) in Example 1 are the same steps, and the steps are different from those in Step (d) of Example 1. Further, the present example is also a modification before the step (e-2) of the second example. Therefore, FIG. 5 shows (a-3) to (c-3) corresponding to the step (d) before Example 1 and the step (e-2) before Example 2.

  As shown in FIG. 5A-3, a plurality of energy generating elements 103 are arranged on the first surface of the silicon substrate 101. A protective layer 104 is formed on the energy generating element 103 and the silicon substrate 101. A seed layer 105 is formed on the protective layer 104. An opening 120 is disposed on the first surface of the silicon substrate 101 and between the two rows of energy generating elements 103. TaSiN was used as the energy generating element, SiO was used as the protective layer, and gold was used as the seed layer.

  Next, as shown in FIG. 5 (b-3), introduction holes were formed in the first surface exposed to the opening 120.

  Since the silicon substrate is exposed at the opening 120, it is not always necessary to provide the introduction hole. However, when the non-penetrating opening 107 is formed deeply, the opening must be widened. In this embodiment, the opening width of the opening can be reduced by providing the introduction hole.

  Next, as shown in FIG. 5C-3, a non-penetrating opening 107 was formed by wet etching from the first surface of the silicon substrate.

  Thereafter, a substrate for a liquid discharge head was manufactured through steps (e) to (g) of Example 1 or steps (e-2) to (h-2) of Example 2.

  According to this embodiment, it is possible to reduce the step of removing unnecessary portions of the protective layer and the seed layer after the non-penetrating opening is formed.

(Comparative Example 1)
The comparative example 1 is demonstrated using FIG.
As shown in FIG. 2A, a silicon substrate was prepared. A layer 21 containing scratches is formed on the second surface side of the silicon substrate.
Next, as shown in FIG. 2B, the silicon substrate was thinned by polishing from the second surface of the silicon substrate. Damaged portions 22 are formed on the second surface side of the silicon substrate.
Next, as shown in FIG. 2C, an etching mask 23 was formed on the second surface side of the silicon substrate.
Next, as shown in FIG.2 (d), it etched using TMAH (22 wt%) and the etching temperature of 80 degreeC.
As a result, the etching progressed irregularly at the damaged portion, and the opening width of the liquid supply port on the second surface could not be formed with high accuracy.
(Comparative Example 2)
In Comparative Example 2, in Example 1, the silicon substrate is first polished from the second surface, and then the penetrating liquid supply port is formed using wet etching. Comparative Example 2 will be described with reference to FIG.

  As shown in FIG. 6A, a silicon substrate similar to that in Example 1 was prepared. Thereafter, as shown in FIG. 6B, the silicon substrate was thinned by polishing from the second surface of the silicon substrate. At this time, a damaged layer 22 was formed on the second surface of the silicon substrate by polishing. The polishing method follows that in Example 1. Next, as shown in FIG. 6C, a non-penetrating etchant introduction groove is formed from the first surface side of the silicon substrate, and a through-liquid supply port is formed in the silicon substrate using wet etching as shown in FIG. Formed. At this time, the anomaly formation part which advanced from the damaged layer 22 generated in the polishing step and the penetrating liquid supply port were connected, and the opening width of the liquid supply port on the second surface could not be formed with high accuracy.

DESCRIPTION OF SYMBOLS 1 Substrate 5 Energy generating element 15 Flow path forming member 16 Ejection port 17 Liquid supply port 18 Liquid flow path 21 Scratched layer 22 Damaged portion 23 Etching mask 24 Abnormal formation part 101 Substrate 102 Sacrificial layer 103 Energy generating element 104 Protective layer 105 Seed layer 106 Introduction hole 107 Unpenetrated opening 108 Flow path forming member 109 Dicing groove 110 Unpenetrated dicing groove 120 Opening

Claims (9)

A method for manufacturing a substrate for a liquid discharge head having a liquid supply port,
(1) preparing a substrate having an energy generating element that generates energy for discharging liquid on the first surface;
(2) performing a wet etching process on the substrate to form a non-penetrating opening in the first surface;
(3) The liquid supply port is formed by opening the non-penetrating opening in the second surface by thinning the substrate from the second surface that is the surface opposite to the first surface. And a process of
A method for manufacturing a substrate for a liquid discharge head, comprising:   The method of manufacturing a substrate for a liquid discharge head according to claim 1, wherein the step (3) is a step of thinning the substrate by polishing.   The method for manufacturing a substrate for a liquid discharge head according to claim 2, wherein an opening size of the liquid supply port on the second surface is controlled by adjusting an amount of the polishing.   4. The method for manufacturing a substrate for a liquid discharge head according to claim 1, wherein the wet etching process is crystal anisotropic etching.   The method for manufacturing a substrate for a liquid ejection head according to claim 1, wherein the non-penetrating opening is configured by a (111) plane.   6. The method according to claim 1, further comprising a step of forming, before the step (2), an unpenetrated introduction hole for introducing an etching solution used for the wet etching process on the first surface of the substrate. The manufacturing method of the liquid discharge head board | substrate of description.   The sacrificial layer which controls the opening dimension of the non-through hole is provided on the first surface of the substrate, and the introduction hole is provided through the sacrificial layer. The manufacturing method of the liquid discharge head board | substrate of description. Prior to the step (3), a non-penetrating groove is formed in the first surface of the substrate,
8. The liquid ejection head according to claim 1, wherein in the step (3), the substrate is divided by thinning the substrate and causing the non-penetrating groove to penetrate the second surface. 9. Manufacturing method for industrial use. After the step (2), the method includes a step of forming a discharge port for discharging the liquid and a flow channel forming member for forming a liquid flow channel communicating with the discharge port on the first surface of the substrate. A method for manufacturing a substrate for a liquid discharge head according to claim 1.

Images