Liquid ejecting head

Abstract

The liquid ejecting head having a plurality of ejecting ports includes: a first substrate having an energy generating element in one surface and a first supply port passing through the first substrate from the one surface to the other surface; and a second substrate bonded to the first substrate with an adhesive in the lamination direction and including a second supply port communicating with the first supply port and passing through the second substrate from the bonding surface to the other surface. Each first supply port includes: a first portion including a first opening formed in the first bonding surface; and a third portion including a third opening formed on a side including the energy generating element, the third opening having an opening area smaller than an opening area of the first opening. The side surface and the upper side intersect at an obtuse angle in the first portion. Each second supply port includes a second opening in the bonding surface. The width W1 of the first opening and the width W2 of the second opening satisfy W1gt in at least one of an arrangement direction of the ejection ports and a direction orthogonal to the arrangement direction; w2.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head using a substrate assembly in which a plurality of substrates are bonded together. Background Art

[0002] Many micro-electromechanical systems (MEMS) devices are manufactured by bonding substrates together. An example thereof is a liquid ejection head that ejects liquid.

[0003] An example of a liquid ejection head is an inkjet print head. The inkjet print head includes an energy generating element to provide energy for ejecting ink. An ejection port forming member is formed on the surface of a substrate, and an ejection port for ejecting ink is opened in the ejection port forming member. A through hole is formed in the substrate, and ink is supplied from the back side of the substrate to the front side through the through hole. The through hole serves as an ink channel through which ink flows.

[0004] As a method for manufacturing an inkjet print head, an adhesive bonding technique is generally used, in which substrates are bonded together using an adhesive such as a resin. During bonding, the adhesive is squeezed and moved into the channel as excess adhesive. This excess adhesive may clog the ink channel. Clogging the ink channel is problematic because it causes ejection failure by preventing the ink from flowing through.

[0005] Japanese Patent Laid-Open No. 2004-249668 (hereinafter referred to as Patent Document 1) proposes that when silicon substrates having ink channels processed therein are bonded to each other, slits provided in bonding surfaces of partition walls each located between liquid channels absorb excess adhesive, thereby reducing the amount of excess adhesive. Summary of the invention

[0006] In the case of providing the slits as in Patent Document 1, there is a risk that the partition wall may be damaged during the manufacturing process because the strength of the partition wall is reduced. In addition, the need to reserve a space in the partition wall for providing the slits makes it difficult to reduce the width of the partition wall, which also makes it difficult to improve performance by arranging pressure chambers at a higher density and to reduce costs by reducing the chip size.

[0007] One example of the present disclosure is a liquid ejection head in which a plurality of ejection ports are arranged, the liquid ejection head comprising: a first substrate having an energy generating element in one surface and a first supply port that passes through the first substrate from the one surface to a first bonding surface as another surface; and a second substrate, the second substrate being bonded to the first bonding surface of the first substrate along a stacking direction at the second bonding surface using an adhesive interposed between the second bonding surface and the first bonding surface, and the second substrate having a second supply port communicating with the first supply port, the second supply port passing through the second substrate from the second bonding surface to another surface of the second substrate. Each of the first supply ports has a first portion and a third portion, the first portion including a first opening formed in the first bonding surface, the third portion including a third opening formed on a side including the energy generating element in the first substrate, the opening area of ​​the third opening being smaller than the opening area of ​​the first opening. In the first portion, a side surface and an upper side as a portion connected to the third portion intersect and form an obtuse angle. Each of the second supply ports has a second opening in the second bonding surface. In at least one of an arrangement direction of the ejection ports and a direction orthogonal to the arrangement direction, a width W1 of the first opening and a width W2 of the second opening satisfy W1>W2.

[0008] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A-1 to Figure 1E is a cross-sectional view showing a method for manufacturing the liquid ejection head in the first embodiment of the present disclosure;

[0010] Figure 2A and Figure 2B are plan views each showing a positional relationship between openings at a bonding portion;

[0011] FIG. 3A to FIG. 3C is a cross-sectional view showing a first embodiment and a comparative example;

[0012] Figure 4A and Figure 4B are cross-sectional views each showing a positional relationship of a moving adhesive;

[0013] FIG. 5A to FIG. 5C are plan views each showing a positional relationship between openings at a bonding portion;

[0014] FIG. 6A to FIG. 6C are cross-sectional views each showing an adhesive when bonded;

[0015] 7A to 7F are plan views each showing an example of the shape of the second opening;

[0016] Figure 8A-1 to Figure 8E is a sectional view showing a method for manufacturing a liquid ejection head in a second embodiment of the present disclosure;

[0017] Figure 9A-1 to Figure 9B-2 is a cross-sectional view showing a modified example of the method for manufacturing the first substrate in the second embodiment of the present disclosure;

[0018] Fig. 10A and Fig. 10B is a cross-sectional view showing a processing example of the first supply port in the second embodiment of the present disclosure;

[0019] Fig. 10C and Fig. 10D is a bird's-eye view of area C in the second embodiment of the present disclosure;

[0020] FIG. 11A to FIG. 11C is a cross-sectional view showing an example of a method for manufacturing the first supply port and the third supply port in the second embodiment of the present disclosure;

[0021] Fig.12 is a bird's-eye view of an example of a liquid ejection head manufactured in a second embodiment of the present disclosure;

[0022] Fig.13A is a plan view of an example of a liquid ejection head in the present disclosure; and

[0023] Fig. 13B is a plan view of a second substrate bonded to the liquid ejection head in the present disclosure. DETAILED DESCRIPTION

[0024] Hereinafter, examples of embodiments of the present disclosure will be described by using the accompanying drawings. It should be noted that the following description is not intended to limit the scope of the present disclosure. Although the present embodiment uses a thermal system that ejects ink by generating bubbles using a heater element as an example, the present disclosure can also be applied to a liquid ejection head that uses a piezoelectric system and other various liquid ejection systems.

[0025] In the present disclosure, the X-axis, Y-axis, and Z-axis are appropriately used as directional axes for explaining the structure of the liquid ejection head, etc. The X-axis and the Y-axis are orthogonal to each other in the horizontal plane and constitute a liquid ejection plane. The longitudinal axis of the liquid ejection head extends along the Y-axis direction (Y direction), and the print medium moves along the X-axis direction (X direction). The Z-axis is a vertical axis orthogonal to the X-axis and the Y-axis, and the Z-axis direction (Z direction) is the direction in which the first substrate 131 and the second substrate 132 are stacked, as described later.

[0026] (First embodiment)

[0027] Figure 1A-1 to Figure 1E A sectional view showing a method for manufacturing the liquid ejection head according to the present embodiment. Figure 1A-1 and Figure 1A-2 A method for processing a first substrate 131 is shown. A first substrate 131 is prepared in which a circuit and an energy generating element (eg, a heater) 107 ( Figure 1A-1 ). The second surface 142 of the first substrate 131 located opposite to the first surface 141 serves as a bonding surface to be bonded to the second substrate 132, as described later.

[0028] For the first substrate 131, silicon is preferably used. This is because semiconductor elements (such as transistors constituting a circuit) must be formed in the first substrate 131. The second surface 142 (back side) of the first substrate 131 is processed to thin the first substrate 131 to a desired thickness. If not necessary, the substrate thinning process can be omitted. Next, the second surface 142 of the first substrate 131 is smoothed. Smoothing is performed by polishing (for example, grinding, dry polishing, or chemical mechanical polishing (CMP)).

[0029] Next, if Figure 1A-2 As shown, a first supply port 112 is processed in the first substrate 131. In the present embodiment, the first supply port 112 is opened as a through hole that passes through the first substrate 131 to reach the second surface 142. The opening of each first supply port 112 in the second surface 142 is defined as a first opening 151. The perimeter of the above-mentioned opening is defined as the perimeter of the first opening 151. The shape of the first supply port 112 is, for example, a groove shape extending in the longitudinal direction. Examples of processing methods include chemical dry etching, chemical wet etching, laser, sandblasting, etc.

[0030] Figure 1B-1 and Figure 1B-2 A method for processing the second substrate 132 is shown. Figure 1B-1 ). For the second substrate 132, silicon or resin material can be used, but a silicon substrate is preferred, which has higher strength than a resin material and is stable in a liquid. The surface of the second substrate 132 to be used as a bonding surface is referred to as a third surface 143, and the opposite surface is referred to as a fourth surface 144.

[0031] In the second substrate 132, a second supply port 113 ( Figure 1B-2 The processing method is the same as the method used to process the first supply port 112. The second supply port 113 includes a large number of through holes that pass through the second substrate 132 from the third surface 143 to the fourth surface 144 and are smaller than the first supply port 112.

[0032] The opening of each second supply port 113 formed in the third surface 143 is defined as a second opening 152. The perimeter of the above-mentioned opening is defined as the perimeter of the second opening 152.

[0033] Figure 1C to Figure 1E FIG. 2 shows an assembly operation for a liquid ejection head including a first substrate 131 and a second substrate 132. An adhesive 121 ( Figure 1C ). For the adhesive 121, a material having high adhesion to the substrate is recommended. From the viewpoint of coating quality, a material containing few bubbles or the like therein is preferred, or a material having low viscosity is preferred, with which the adhesive 121 can be easily and thinly coated. As the material, there are epoxy resin, acrylic resin, silicone resin, benzocyclobutene resin, polyamide resin, polyimide resin, and polyurethane resin.

[0034] The first substrate 131 coated with the adhesive 121 is aligned with the second substrate 132 by an alignment device, and the second substrate 132 is placed below the first substrate 131 in the direction of gravity. Next, the stacked substrates thus aligned are clamped and preliminarily fixed by a clamping mechanism or the like. The preliminarily fixed stacked substrates are transferred to a bonding device. In the bonding device, the stacked substrates are heated to a predetermined temperature and then bonded together by being pressed at a predetermined pressure for a predetermined time. These bonding parameters are appropriately set according to the adhesive material. In addition, it is preferred to perform bonding in a vacuum to prevent bubbles from entering the bonding portion.

[0035] In the case where the adhesive 121 is a thermosetting type, the substrates may be heated in the bonding apparatus until the adhesive is cured. Alternatively, the substrate assembly may be removed after bonding and then heated in a separate oven or the like to cure the adhesive.

[0036] After the adhesive is completely cured, the first supply port 112 and the second supply port 113 are connected to each other to form a channel 115 ( Figure 1D In this embodiment, the plurality of second supply ports 113 are connected to one first supply port 112. The perimeter of the first opening 151 is longer than the perimeter of the second opening 152.

[0037] Figure 2A A plan view is shown in which a preferred positional relationship between the first opening 151 and the second opening 152 is drawn. Figure 2A The diagram shows the first surface 141 viewed from the side. Figure 1D The first opening 151 and the second opening 152 of the substrate assembly case.

[0038] In this embodiment, a plurality of second openings 152 are arranged in the longitudinal direction (Y direction) of each first opening 151. The perimeter of the second opening 152 is shorter than the perimeter of the first opening 151. The length of the first opening 151 in the short side direction (X direction) is W 1X The length of the second opening 152 in the short side direction (X direction) is represented by W 2X Similarly, the length of the first opening 151 in the longitudinal direction (Y direction) is represented by W 1Y The length of the second opening 152 in the longitudinal direction (Y direction) is represented by W 2Y express.

[0039] exist Figure 2A In, W 1X >W 2X It holds true in the short side direction and also satisfies W in the longitudinal direction 1Y >W 2Y This embodiment is preferred because the width W1 of the first opening 151 and the width W2 of the second opening 152 satisfy the relationship W1>W2 not only in the X direction and the Y direction but also in any direction around 360°. As described later, in the case of this structure, Figure 1D As shown, the adhesive travels upward (in the Z direction) toward the first supply port 112 .

[0040] Next, an ejection port forming member is formed on the first surface 141 side of the substrate assembly. A dry film resist in which a film base material is coated with a photocurable resin is bonded to the first surface 141 of the substrate assembly. Thereafter, the wall 118 of the ejection port forming member is patterned by exposure and development. Subsequently, a top plate 119 of the ejection port forming member is formed on the wall 118 in a similar manner. For example, a dry film resist is bonded to the wall 118, and then the dry film resist is exposed and developed so that the top plate 119 having the ejection port 101 is formed, thereby completing the liquid ejection head ( Figure 1E ).

[0041] In the present embodiment, the first substrate 131 is a substrate including the energy generating element 107, the ejection port forming members 118 and 119 having the ejection port 101, and the driver IC in the first surface 141. Therefore, the first supply port 112 has a function for supplying liquid to the energy generating element 107. The liquid heated by the energy generating element 107 is ejected from the ejection port 101. The first substrate 131 can be used as a liquid ejection head substrate.

[0042] exist Figure 2AIn the embodiment shown in , the first supply port 112 has a large groove shape and extends in the longitudinal direction (direction Y). In order to increase the speed of supplying liquid to the plurality of ejection ports and the heater element provided in the first surface 141, the volume of the first supply port 112 is preferably large.

[0043] The second substrate 132 includes the second supply port 113, and has a function of collecting the liquid passage of each first supply port 112 in a planar direction and connecting the first supply port 112 to a fourth supply port formed in a base member located below the fourth surface 144 of the second substrate 132. The width of the fourth supply port and the adjacent supply port spacing are wider than those of the first supply port 112 and the adjacent supply port spacing.

[0044] like Figure 2A As shown, the plurality of second supply ports 113 are connected to the interior of the first opening 151 of each first supply port 112. Each second supply port 113 is a through hole having a volume smaller than that of the first supply port 112, and the circumference of the second opening 152 is also shorter than that of the first opening 151. The cross section of the second opening 152 in the substrate assembly is as shown in FIG. Figure 1E The second substrate 132 serves as a member for changing the interval between the liquid supply ports of the first substrate 131 (liquid ejection head substrate).

[0045] Figure 2B FIG. 1 shows a substrate assembly in a modified example of the present embodiment, wherein the width W1 of the first opening 151 and the width W2 of the second opening 152 have a relationship W1<W2 in one direction. Figure 2A Similarly, the plurality of small through holes of the second supply port 113 communicate with each of the first supply ports 112 in the shape of a large groove.

[0046] However, in this modification, there is a direction in which the perimeter of the first opening is shorter than the perimeter of the second opening. 1y >W 2y In the vertical direction (Y direction), W 1X <W 2X This is true in the short-side direction (X direction). Therefore, as described later, the adhesive pushed out from the bonding portion in the short-side direction may have an adverse effect in some cases.

[0047] The second supply port 113 collects liquid from the first supply port 112 in the shape of a large groove and connects the first supply port 112 to the Figure 1E Each of the plurality of second supply ports 113 may be selectively connected to any one of the plurality of fourth supply ports.

[0048] For example, each second supply port 113 can be connected to a supply port upstream or downstream of the ejection port in the liquid circulation, or can be connected to a supply port for the same color when different kinds of ink are used. Since the second supply port 113 is small, the second supply port 113 can be connected to the desired pair of the first supply port and the fourth supply port separately from the other supply ports. Therefore, there is a problem that the second opening 152 tends to have a shorter perimeter and is blocked by the adhesive.

[0049] Therefore, making it difficult for the adhesive 121 to move to the second supply port 113 is effective in preventing clogging. On the other hand, excess adhesive is generated around the bonding portion due to movement with the bonding. In this embodiment, the movement of the excess adhesive can be controlled according to the positional relationship between the opening of the first supply port 112 and the opening of the second supply port 113, so that the excess adhesive can be difficult to move to the second supply port 113.

[0050] FIG. 3A to FIG. 3C The relationship between a conceivable position of the opening and a conceivable movement of the adhesive 121 is each shown. FIG. 3A to FIG. 3C Different situations depending on the size relationship between the width W1 of the first opening 151 and the width W2 of the second opening 152 are shown.

[0051] Figure 3A A case of W1 > W2 is shown, in which the adhesive 121 is pushed out from between the bonding surfaces and travels upward toward the first supply port 112 (+Z direction). Figure 3B A case where W1 = W2 is shown, in which the adhesive 121 moving from the side of the bonding surface goes upward along the side of the first supply port 112 and goes downward along the side of the second supply port 113 .

[0052] Figure 3C The case of W1<W2 is shown. In this case, the adhesive 121 reaching the first opening 151 stops moving in the horizontal direction due to surface tension. Then, the adhesive 121 moves downward toward the side of the second supply port 113 (-Z direction).

[0053] Figure 3B and Figure 3C is a comparative example, in which the adhesive 121 moves downward toward the second supply port 113 (in the -Z direction), and thus may block the second supply port 113. In contrast, Figure 3A This is an example of W1>W2, where adhesive 121 reaching second opening 152 stops moving in the horizontal direction due to surface tension and moves upward along the side of first supply port 112. In this case, adhesive 121 is less likely to enter second supply port 113, which is advantageous as an embodiment of the present disclosure.

[0054] A more preferable example in the case where W1>W2 is satisfied will be described below. Figure 4A and Figure 4B 1 is a cross-sectional view of a bonding portion of the first substrate 131 and the second substrate 132 when the adhesive is cured. Figure 4A The adhesive 121 shown in the figure reaches the second opening 152. Figure 4B The illustrated case where the adhesive 121 does not reach the second opening 152 is more preferred.

[0055] This is because, after the adhesive 121 reaches the opening, the excess adhesive moves upward along the side of the first supply port 112 due to surface tension. The adhesive 121 moving upward along the side of the first supply port is larger than the adhesive 121 moving upward along the side of the first supply port. Figure 4B Therefore, unlike the case where the adhesive 121 does not move upward ( Figure 4B ), the contact area between the adhesive 121 and the first substrate 131 is increased, and the adhesive strength is enhanced.

[0056] From the viewpoint of enhancing such bonding strength, the larger the number of the second supply ports 113 , the more preferable it is. FIG. 5A to FIG. 5C 1 and 152 show an example of the arrangement of the first opening 151 and the second opening 152. Figure 5B In this case, only one second supply port 113 is connected to each first supply port 112. Compared with this case, it is preferable to arrange a large number of second supply ports 113, such as Figure 5A This is because, when the sum of the lengths A of the portions around the second opening 152 in contact with the adhesive 121 increases, the area where the adhesive 121 moves upward along the side of the first supply port 112 increases proportionally.

[0057] In addition, it is also preferable to evenly arrange the second supply port 113 (ie, the second opening 152) over the entire first supply port 112 (ie, the first opening 151) in the longitudinal direction because the entire first supply port 112 can be evenly combined. Figure 5C The second openings 152 arranged around both ends and the center of the first opening 151 as shown can enhance the adhesive strength at the entire first supply port 112. For this reason, it is preferred that three or more second supply ports 113 are arranged for each first supply port 112.

[0058] The conditions for allowing the adhesive 121 to reach the second opening 152 will be described. Fig. 6A 1 shows a cross-sectional view before bonding, in which the adhesive 121 is applied to the second surface at the partition wall 153 of the first substrate 131. The adhesive volume V per unit length in the depth direction (Y direction) corresponds to Fig. 6A The area of ​​the adhesive 121 is as follows.

[0059] In the case where the adhesive 121 is squeezed and moved after bonding, the adhesive 121 moves an equal distance in the X direction and the Z direction from the bonding portion due to surface tension, and forms an adhesive pool 154 illustrated as an isosceles triangle cross section on both sides of the partition wall 153. Figure 6B If the adhesive pool 154 moves as shown, the width L of the adhesive pool 154 is expressed by equation (1) using the adhesive volume V, as shown below.

[0060] L 2 = V (1)

[0061] In order for the adhesive 121 to advance on the second substrate 132 and reach the second opening 152, at least the distance d from the end of the first opening 151 (the end of the partition wall) to the end of the second opening 152 needs to be equal to or less than L. Therefore, as a condition for allowing the adhesive 121 to reach the second opening 152, the formula (2) shown below needs to be satisfied.

[0062] d ≤ (V) 0.5 (2)

[0063] For example, in Fig. 6A When the adhesive volume V is simply expressed by adhesive thickness T×partition wall width S, equation (2) is transformed into equation (3).

[0064] d ≤ (T×S) 0.5 (3)

[0065] In the case where the first opening and the second opening are positioned concentrically, formula (3) is transformed into formula (4).

[0066] W1 - W2 ≤ 2×(T×S) 0.5 (4)

[0067] Therefore, in order for the adhesive 121 to reach the second opening 152 , the distance d from the end of the second opening 152 to the end of the first opening 151 must be set equal to or smaller than the distances represented by formulas (2) to (4).

[0068] In addition, the adhesive volume V can be measured from the bonded substrates. For example, in the case where the first supply ports 112 are arranged along the short side direction (X direction), the cross section at the bonded portion is exposed and observed in the short side direction. In the cross section observed around the partition wall 153 between the first supply ports 112, the area of ​​the adhesive portion corresponds to the adhesive volume V.

[0069] Figure 6CA typical example of the cross section is shown. The adhesive is squeezed so that a portion of the adhesive remains on the bonding surface and another portion moves to both sides of the partition wall 153. The shape of the adhesive 121 originally present on the partition wall 153 changes to the shape of the dot-shaped area B. Therefore, after bonding, the area of ​​the dot-shaped area B corresponds to the adhesive volume V. Methods for exposing the cross section include various cutting methods, FIB, CMP, etc. Observation methods include SEM and TEM.

[0070] A preferred shape of the second supply port 113 will be described. 7A to 7F A plan view of a second opening present in the third surface is shown. Fig. 7A A rectangular shape is shown as a typical shape. Fig. 7A In the rectangular shape in FIG. 1 , capillary force from the four vertices (corners) to the inside of the second supply port 113 is more likely to act and help the adhesive 121 enter the second supply port 113 .

[0071] To solve this problem, Figure 7B , Figure 7C , Fig.7D and Fig. 7E As shown, a shape without corners having vertices is formed by replacing the corners with arcs. In this shape, capillary force is less likely to act on the adhesive 121, so the adhesive 121 is less likely to enter the interior of the second supply port 113.

[0072] Figure 7B shows an ellipse, while Figure 7C An oblong shape consisting of semicircles and rectangles is shown. Fig.7D shows a rectangular shape with only arcs replacing the corners, while Fig. 7E A circular shape is shown. Figure 7F The octagonal shape in is also preferred because each vertex has a larger angle than the rectangular shape, making it easier to Fig. 7A The capillary force is weaker than that of the second supply port 113 and the adhesive 121 is less likely to enter the interior of the second supply port 113. Instead of the octagonal shape, any polygonal shape having more than 5 sides and obtuse vertices may be used. Fig. 7A The adhesive is more effectively prevented from entering the second supply port 113. Therefore, preventing the adhesive 121 from moving to the second supply port 113 as described above helps the adhesive 121 to move upward along the side of the first supply port 112.

[0073] Furthermore, it is preferred that Figure 3AThe depth Z1 of the first supply port 112 shown in FIG is as large as possible. This is because a large amount of adhesive 121 can be held on the side of the first supply port 112. It is preferable to design the liquid ejecting head so that the depth Z1 of the first supply port 112 is at least greater than the depth Z2 of the second supply port 113. In particular, in the case where the total thickness of the bonded substrate is fixed, it is desirable to make the first supply port 112 as deep as possible.

[0074] (Second embodiment)

[0075] When adhesive 121 moves upward along the side of first supply port 112 as described in the first embodiment, there is a risk that adhesive 121 reaches first surface 141 and further reaches an energy generating element provided in first surface 141, deteriorating ejection performance, depending on the amount of adhesive 121.

[0076] In order to solve this problem, in this embodiment, an example in which the first supply port 112 is formed in an overhanging shape will be described. Fig. 8E A sectional view showing a method for manufacturing the liquid ejection head according to the present embodiment.

[0077] Figure 8A-1 and Figure 8A-2 A method for processing the first substrate 131 is shown. A first substrate 131 ( Figure 8A-1 ), and a supply port is processed in the first substrate 131. In this step, a Figure 8A-2 The first supply port 112 combined with the third supply port 114 is shown to replace the first supply port 112 described in the first embodiment.

[0078] The first supply port 112 is processed from the second surface 142 to the middle of the first substrate 131, and the third supply port 114 is communicated with the side (upper side) of the first supply port 112 opposite to the second surface 142. The opening formed on the upper side of each first supply port 112 is defined as a third opening 158. The width of the third supply port 114 in the X direction is narrower than the width of the first supply port 112 in the X direction (in other words, the opening area of ​​the third opening 158 is smaller than the opening area of ​​the first opening 151), so that the upper side of the first supply port 112 serves as the hanging portion 155.

[0079] After the first supply port 112 is machined from the second surface 142 and the machining stops in the middle of the first substrate 131, the third supply port 114 may then be machined from the first surface 141 to communicate with the first supply port 112. Alternatively, after the first supply port 112 is formed, the narrower third supply port 114 may be continuously machined to pass through the first substrate 131 to reach the first surface 141.

[0080] There are several possible methods for processing the first supply port 112. These methods include chemical dry etching, chemical wet etching, laser, sandblasting, cutting, and the like.

[0081] After the first substrate 131 is processed, the second substrate 132 is processed in the same manner as in the first embodiment to form the second supply port 113 ( Figure 8B-1 and Figure 8B-2 ), and then the second substrate is bonded to the first substrate 131 ( Figure 8C and Fig.8D After the adhesive for bonding is cured, an ejection port forming member is formed on the first surface 141 to complete the liquid ejection head ( Fig. 8E ).

[0082] In this embodiment, Fig.8D In the bonding step in , the adhesive 121 that goes upward along the side of the first supply port 112 can be blocked by the upper side (overhanging portion 155) of the first supply port 112. Since the adhesive 121 is blocked by the overhanging portion 155, the adhesive 121 is less likely to reach the third supply port 114 or exceed the first surface 141 of the third supply port 114, thereby preventing the energy generating element 107 in the first surface 141 from being degraded.

[0083] In another mode of the method for forming the overhang portion 155, as Figure 9A-1 to Figure 9A-3 As shown, an SOI substrate may be used as the first substrate 131. In this case, the overhanging portion 155 may be formed by processing the first supply port 112 from the second surface 142 to the oxide film 157 of the SOI substrate, then processing the third supply port 114 from the first surface 141, and finally removing the oxide film 157.

[0084] Instead, if Figure 9B-1 and Figure 9B-2As shown, the overhanging portion 155 may be formed by forming a thin film layer 156 made of an oxide film, a resin film, or a multilayer film of these films on the first surface 141 of the first substrate 131. For example, the overhanging portion 155 may be formed by processing the first substrate 131 to the thin film layer 156 and then processing the third supply port 114 in the thin film layer 156. The thin film layer 156 is set to have a film structure that can maintain sufficient strength and rigidity even after the substrate portion supporting the thin film layer 156 is removed.

[0085] In a more preferred shape of the first supply port 112 , a suspended surface to be used as an upper side of the first supply port 112 is curved. Fig. 10A A cross-sectional view of a first substrate 131 processed in a general manufacturing method is shown. Fig. 10C Shows Fig. 10A FIG. 1 is a bird's-eye view of a region C (near the overhanging portion 155 ) in a cross section of the first substrate 131 .

[0086] like Fig. 10C As shown, the overhanging surface 161 is ideally processed into a flat surface, but the overhanging surface 161 in the case of a flat surface forms a right angle with the other side of the first supply port 112. Fig. 10C The other side is the first supply port side surface 162, and there is an edge line 163 where the first supply port side surface 162 intersects with the suspension surface 161. The edge line 163 extends along the Y direction (the longitudinal direction of the supply port). The angle formed between the above two surfaces forming the edge line is a right angle ( Fig. 10C The angle at point E in the graph).

[0087] In the case of an edge line having a right-angle cross section, if adhesive 121 travels up to edge line 163, adhesive 121 tends to move along edge line 163 due to capillary force. Adhesive 121 tends to gather at edge line 163 and spread over the entire edge line 163.

[0088] If a large amount of adhesive 121 gathers at edge line 163, adhesive 121 also moves onto suspended surface 161 present in the X direction and eventually reaches third supply port 114. This may cause a problem in which the adhesive blocks the third supply port and reaches first surface 141 by moving upward along the side of the third supply port.

[0089] In order to solve this problem, it is preferred that the suspension portion 155 is processed into a curved shape, such as Fig. 10B shown. Fig. 10D Shows Fig. 10B 14. A bird's-eye view of the region D in FIG. The suspension surface 161 is curved so that its end portions are closer to the second surface 142 than its center portion.

[0090] Therefore, the overhanging surface 161 and the first supply port side surface 162 form an obtuse angle at their intersection. In addition, since the overhanging surface 161 is bent and connected to the first supply port side surface 162, at their connection point ( Fig. 10D There is no corner at point E). Therefore, Fig. 10D In the embodiment, since it is difficult to move along the edge line 163 due to the capillary force, the adhesive 121 is dispersed and is less likely to reach the third supply port 114 .

[0091] An effective manufacturing method for curving the suspended surface at the bottom of the first supply port 112 is to form the first supply port 112 by processing using silicon dry etching and stopping the etching in the middle of the silicon substrate.

[0092] FIG. 11A to FIG. 11C The manufacturing flow chart thereof is shown. A first substrate 131 ( Fig.11A ).exist Fig. 11B In the embodiment, the first supply port 112 is processed from the second surface 142 of the first substrate 131 by dry etching, and the etching is stopped in the middle of the substrate. Then, the third supply port 114 ( Fig. 11C ). The third supply port 114 may be processed in any manner.

[0093] exist Fig. 11B In the process of dry etching, the silicon substrate is etched using an etchant gas (in which SF6, Cl2, CF4, etc. are radicalized or ionized) by dry etching. Since the density of the etchant gas becomes high at the center of the first supply port 112, the suspended surface 161 tends to be deeper at the center portion and shallower at the peripheral portion. Fig. 11B and Fig. 11C As shown, the overhang surface 161 may be curved.

[0094] Even in the case of dry etching, if the suspended portion 155 is used as an etching stopper as shown in FIGS. 9A and 9B , the suspended portion 155 does not bend. Fig. 11B If the processing in the embodiment uses another method, ie, wet etching, the etchant molecules uniformly enter the first supply port 112 and the suspended portion 155 is not easily bent.

[0095] Preferably, the third opening 158 has a shape that makes it difficult for the adhesive 121 to enter the third opening 158 when the adhesive 121 travels upward along the hanging portion 155. With any preferred shape for the second opening 152, the third opening 158 can prevent the adhesive 121 from entering the third opening 158. Specifically, FIG. 7B to FIG. 7F The shape in is preferred.

[0096] Fig.12 A bird's-eye view of an example of a liquid ejection head manufactured in this embodiment is shown. A first substrate 131 is used as a substrate for ejecting liquid. A second substrate 132 is used as a substrate for changing the interval between liquid supply ports.

[0097] The second substrate 132 allows the first supply ports 112 arranged at a narrow pitch to communicate with the fourth supply ports (not shown) in the base member (located below the second substrate 132) via the tiny second supply ports 113. Since the fourth supply ports are configured to have a width wider than that of the first supply ports 112 or an adjacent pitch wider than that of the first supply ports, the second substrate 132 performs conversion from the first supply ports 112 at a narrow pitch to the fourth supply ports at a wide pitch.

[0098] Liquid along Fig.12 The arrows indicated by F in FIG. 1 and 2 are circulated. The adjacent first supply ports are used as a liquid inlet and a liquid outlet, respectively, thereby preventing the liquid from adhering to the ejection ports 101 between the first supply ports. The circulating liquid moves to a fourth supply port (not shown) through the second supply port 113.

[0099] Fig.13A Shows Fig.12 A plan view of a liquid ejecting head in FIG. Fig. 13B 1 shows an example of a plan view of the second substrate 132. In the liquid ejection head, a plurality of first supply ports 112 are arranged, and the second supply ports 113 are arranged along the longitudinal direction of the first supply ports 112. Fig. 13B As shown, the second opening 152 has an oblong shape. Three or four second supply ports 113 are connected to each first supply port 112 and are arranged approximately evenly at the center and ends of the first supply port 112. Then, the width W1 of the first supply port 112 and the width W2 of the second supply port 113 satisfy W1>W2.

[0100] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications and equivalent structures and functions.

Claims

1. A liquid ejection head, in which a plurality of ejection ports are arranged, the liquid ejection head comprising: a first substrate having an energy generating element in one surface and a first supply port passing through the first substrate from the one surface to a first bonding surface as the other surface; as well as a second substrate, the second substrate being bonded to the first bonding surface of the first substrate along a stacking direction at a second bonding surface using an adhesive interposed between the second bonding surface and the first bonding surface, and the second substrate having a second supply port communicating with the first supply port, the second supply port passing through the second substrate from the second bonding surface to another surface of the second substrate, wherein Each of the first supply ports has a first portion and a third portion, the first portion including a first opening formed in the first bonding surface, the third portion including a third opening formed in the first substrate on a side including the energy generating element, the opening area of ​​the third opening being smaller than the opening area of ​​the first opening, In the first portion, the side surface and the upper side as a portion connected to the third portion intersect and form an obtuse angle, Each of the second supply ports has a second opening in the second bonding surface, and In at least one of an arrangement direction of the ejection ports and a direction orthogonal to the arrangement direction, a width W1 of the first opening and a width W2 of the second opening satisfy W1>W2.

2. The liquid ejecting head according to claim 1, wherein: An ejection-port forming member having the ejection ports is provided on a surface of the first substrate including the energy generating elements.

3. The liquid ejection head according to claim 1, further comprising a base member including a fourth supply port having a width wider than that of the first supply port or an adjacent pitch wider than that of the first supply port, wherein The base member is bonded to the second substrate, and The second substrate allows the first supply port to communicate with the fourth supply port through the second supply port.

4. The liquid ejecting head according to claim 1, wherein forming a pool of adhesive continuously from a bonding portion of the second substrate to the second opening, and The adhesive pool is in contact with the second opening.

5. The liquid ejecting head according to claim 1, wherein The first supply ports each extend along the arrangement direction of the ejection ports and are arranged in a direction orthogonal to the arrangement direction of the ejection ports, a partition wall is interposed between the first supply ports, and Satisfy d≤(V) 0.5 , in, V represents the volume per unit length of the adhesive pressed by the partition wall at the time of bonding in the arrangement direction of the ejection ports, and d represents the distance between the partition wall and the adjacent second opening.

6. The liquid ejection head according to claim 1, wherein Satisfy W 1x >W 2x and W 1y >W 2y , in, W 1x represents the width of the first opening in the arrangement direction of the injection ports, W 1y represents the width of the first opening in a direction perpendicular to the arrangement direction of the injection ports, W 2x represents the width of the second opening in the arrangement direction of the injection ports, and W 2y It indicates the width of the second opening in the direction orthogonal to the arrangement direction of the injection ports.

7. The liquid ejecting head according to claim 1, wherein: A depth of the first supply port is greater than a depth of the second supply port.

8. The liquid ejecting head according to claim 1, wherein: In the first supply port, an opening area of ​​the third opening is smaller than an opening area of ​​the first opening.

9. The liquid ejecting head according to claim 8, wherein The first supply ports each extend along the arrangement direction of the ejection ports and are arranged in a direction orthogonal to the arrangement direction of the ejection ports, a partition wall is interposed between the first supply ports, and Each of the first supply ports includes a bent portion between the third opening and the partition wall.

10. The liquid ejection head according to claim 1, wherein The second opening has a shape that partially includes an arc or a polygonal shape each including more than five sides.

11. The liquid ejection head according to claim 1, wherein The third opening has a shape that partially includes an arc or a polygonal shape that includes more than five sides.

12. The liquid ejection head according to claim 1, wherein The first supply ports each extend along the arrangement direction of the ejection ports and are arranged in a direction orthogonal to the arrangement direction of the ejection ports, a partition wall is interposed between the first supply ports, and For each of the first supply ports, three or more of the second supply ports are arranged along the arrangement direction of the ejection ports.

Images