JPH09174850A - Ink jet head and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the distance between a heater adapted to discharge ink and an orifice and to improve the close contact connection of a board that no crosstalk occurs to a top plate by providing one or more recesses at the corner formed at the intersection of the plate of a second member and the connecting surface. SOLUTION: One or more recesses are formed at the corner formed at the intersection between the plate of a second member and a connecting surface, and the ridge to become the one end face of the first member is connected to as to be disposed near the recess of the second member, thereby ensuring the distance between the heater adapted to discharge the ink and the orifice without depending upon the accuracy of an edge shape such as a fillet shape of the corner at the time of manufacturing a top plate. Specifically, recesses 10 are provided in the direction for arranging grooves 3 so that the virtual line (points) of the corner G becomes the side face of the orifice plate 6 side of the recess. The reference characters (a) and (b) are depths of the recesses in the Y and Z direction, i.e., widths of the recesses 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet head used for a recording apparatus and the like, and a method for manufacturing the inkjet head.

[0002]

2. Description of the Related Art As one configuration of an inkjet head, the configuration of an inkjet head as shown in FIG. 1 is disclosed in Japanese Patent Application No. 03-4706. The inkjet head of FIG. 1 is a thermal inkjet head that generates thermal energy according to a recording signal and generates ink to discharge ink. The substrate 1 on the support is provided with a heater as an energy generating means for forming droplets. The top plate (FIG. 2) 2 that is a component of FIG. 1 is provided on the joint surface and is joined to the substrate 1 (hereinafter referred to as the top plate joint).
Are integrally provided with a groove 3 forming a nozzle, an orifice 4 communicating with each groove for discharging a droplet, a dust 5 communicating with a plurality of grooves to form a liquid chamber after joining, and an orifice plate 6 having a plurality of orifices. The top plate having these functional parts can be formed integrally with a liquid crystal polymer, polysulfone, or the like. For example, a process may be used in which an outer portion, a groove, and the like of the top plate are integrally formed, and an orifice passage is formed by excimer laser to open the orifice. The top plate 2 and the substrate 1 are joined so that the relative positions of the orifice and the heater have a predetermined relationship. The joining forms a nozzle, a liquid chamber in which the plurality of nozzles communicate, and the like. In FIG. 1, the top plate 2 and the substrate 1 in a predetermined positional relationship are pressed against each other by a pressing spring 8.
The presser spring 8 has an M-shape, and presses a portion of the top plate corresponding to the liquid chamber at the center of the M shape and presses a portion of the top plate 2 corresponding to the nozzle by line contact.

FIG. 3A illustrates the configuration of the top plate and the substrate near the orifice passage in the vertical cross section of FIG. The orifice plate 6 in the top plate 2 is joined so as to form a line of intersection with the joint surface 9, and specifically, the orifice plate 6 and the joint surface 9 are substantially orthogonal to each other, so that the corner portion G is formed.
Is formed. Among the functional parts, it is particularly important for the inkjet head to control the distance OH between the heater 7 and the orifice 4. For example, when OH is larger than a predetermined value, the flow resistance between the heater 7 and the orifice 4 increases, the ejection amount decreases, and the droplet flying speed decreases. On the other hand, when OH is smaller than the predetermined value, the ejection amount increases and the ink refill from the liquid chamber becomes insufficient. In order to join the two parts so that OH has a predetermined value, in each part, the thickness OP of the orifice plate 6 of the top plate, the distance between the end face F substantially parallel to the heater arrangement direction of the substrate 1 and the heater 7. Management of EH is important. However, when a silicon chip is used as a substrate, a defect called a so-called shell crack may occur on the upper surface of the substrate during chip separation.

The E portion (EL area) of the top plate shown in FIG. 3 (a) covers the defects on these substrates and prevents the leakage of ink and foaming power itself. In order to cover such a defect on the upper surface of the substrate, the E portion of the top plate widely covers the substrate, that is, the ridge portion H of the end face F of the substrate is connected to the joining surface 9 of the top plate.
The OH distance may be designed so as to be close to the intersecting corner G of the orifice plate 6 and, preferably, to abut. As a specific example of the shape of FIG. 3A, in an inkjet head having a discharge amount of about 80 p1, a heater area of 4600 μm ² , a nozzle length of 400 μm, an orifice area of 900 μm ² , and OP = 50 to 60 μm,
EH = 110 μm, EL (length of E part) = 10 to 20 μm
m, OH = 140 to 160 μm was required.

[0005]

However, it is difficult to form the edge of the corner G depending on the material of the top plate and the manufacturing process in the related art. For example, by injection molding of resin, as shown in FIG.
When the top plate is manufactured, a fillet shape with a radius of 5 to 10 μm is partially formed in the corner G due to wear of the mold. In this case, as shown in FIG. 3B, the ridge H of the substrate 1
Cannot be brought close to (a virtual point of) the corner of the top plate, and there is a problem that the OH distance required to secure the ink ejection performance cannot be obtained. Further, if the OH distance is forcibly obtained, as shown in FIG. 3C, a gap occurs between the top plate and the substrate, which causes a so-called crosstalk phenomenon between adjacent nozzles when the heater is driven. It was

Therefore, the present invention solves the above-mentioned problems in the prior art, and secures the distance between the heater and the orifice preferable for ink ejection, regardless of the accuracy of the edge shape such as the fillet shape of the corner at the time of manufacturing the top plate. It is an object of the present invention to provide an ink jet head having a good recording quality and a method for manufacturing the ink jet head, which achieves a good close contact between the substrate and the top plate without causing crosstalk.

[0007]

In order to achieve the above object, the present invention provides a first member having energy generating means,
A second member joined to the first member, having a nozzle groove for ejecting ink by the energy generating means, an orifice for ejecting ink from the nozzle groove being opened, and the first member In an ink jet head provided with a joining surface with a member and a second member having a plate portion that forms an intersecting line, 1 is provided at a corner formed at an intersection of the plate portion and the joining surface in the second member.
It is characterized in that more than one recess is provided.
Further, in the present invention, the first member and the second member each have a ridge portion that is one end surface of the first member and is substantially parallel to the arrangement direction of the energy generating means in the first member. It is characterized in that the members are joined so as to be located in the vicinity of the recesses of the members. And the said recessed part can form the dimension based on the warp deformation amount predicted in advance in the said 2nd member. In the present invention,
The recess may be formed such that the ridge portion that is the one end surface of the first member is closer to the recess of the second member than the nozzle groove disposition range in a range other than the nozzle groove disposition range. Of course, the recess may be formed intermittently. Furthermore, in the method for manufacturing an inkjet head of the present invention, the first member having the energy generating means and the second member joined to the first member, the nozzle groove for ejecting ink by the energy generating means. And a second member which has an orifice for ejecting ink from the nozzle groove and which has a plate portion forming an intersection line with the joint surface with the first member. , One or more recesses are formed in a corner portion formed at an intersection of the plate portion and the joint surface in the second member before the first member and the second member are joined. . In the present invention, the recess may be formed either before or after the second member is manufactured. In the present invention, the recess is
At least in the range where the nozzle groove is arranged, the straightness in the direction of arrangement of the nozzle groove at the corner is Δy, and the width of the recess in the direction orthogonal to the direction of arrangement is defined as Δy. When a, the relationship between them is a ≧ Δ
It can be formed based on the warp deformation amount predicted in advance so that it becomes y.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, as described above, one or more recesses are provided in a corner formed at the intersection of the plate portion and the joint surface in the second member, and By joining the ridges that are the one end faces of one member so that they are located near the recesses of the second member, ink ejection is performed irrespective of the accuracy of the edge shape such as the fillet shape of the corner at the time of manufacturing the top plate. It is possible to secure a preferable distance between the heater and the orifice. Further, according to the above configuration of the present invention, even if a defect such as a fillet shape or a chamfered shape occurs in the corner in the manufacturing process of the top plate, and the edge precision of the corner cannot be obtained, the By additionally processing the recesses so as to remove the fillet shape at the corners, it is possible to join the two so that the ridge H of the substrate is preferably located at the E portion of the top plate or in the vicinity of the corners.

In the present invention, when the top plate is provided with the recess, the depth of the recess recessed in the direction of the orifice passage is preferably 1 μm or more in order to reduce variations in discharge performance among a plurality of nozzles. And a value that does not communicate with the orifice passage. Specifically, the size of the undesirable shape (fillet or the like) at the corner of the top plate is often non-uniform in the X direction. For this reason, controlling the depth of the digging to 0 requires, on the contrary, a die for the present invention, an additional process, and the like.
The procedure may be complicated and the cost may increase.
In order to achieve the object of the present invention to achieve good top plate bonding, it is sufficient to set the digging depth to a value of 1 μm or more in the positive Z direction in consideration of the margin for forming the recess. is there.

Incidentally, Japanese Patent Application No. 06-60665 discloses a method of forming a joint surface including an orifice plate and a corner portion by simultaneous cutting. The simultaneous cutting method is effective when the warp of the top plate in the nozzle disposition direction is large or when the nozzle disposition range is 50 mm to 100 mm and the warp state and the distribution of the fillet shape are complicated.
On the other hand, according to the present invention, when the warp amount and the distribution of the fillet shape are relatively small, and the nozzle arrangement range is 20 mm.
It is effective for the following top plates, and in that case, good top plate joining can be achieved more easily than with the simultaneous cutting method.

[0011]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples and other specific shapes. [Embodiment 1] FIGS. 4 to 6 show the structure of a top plate according to Embodiment 1 of the present invention. Figure 4 for ease of explanation
Set the XY coordinates at. Further, in order to explain the shape of the corner portion formed at the intersection of the orifice plate and the joint surface of the top plate of the present embodiment, details thereof are shown in the enlarged view of the portion A of FIG. 4 in FIG. 6 is CC of FIG.
It is a cross section. In this embodiment, as shown in FIG. 5, the recesses 10 are provided in the X direction in which the grooves 3 are arranged so that the virtual line (point) of the corner G is on the side surface of the recess on the orifice plate 6 side. Is. That is, a = al in FIG. 6, a and b are the width of the recess 10 in the Y direction,
It is the width or depth in the Z direction. The recess 10 may be provided in advance, for example, when the top plate is integrally molded. Further, it may be formed by an additional process after molding the top plate and before joining to the substrate.

FIG. 7 is a diagram for explaining the manufacturing process in the latter case, that is, the manufacturing process after the top plate is molded and before the bonding to the substrate. The process will be described with reference to FIG. 7, and in this process, a resin molded product such as polysulfone is used as a top plate, and a portion where a concave shape is to be processed is irradiated with a patterned excimer laser light through a light shielding mask. The outer shape of the top plate is obtained by integrally molding the orifice plate 6 and the groove 3 (FIG. 7A). EL = 20 here
and the fillet radius at the removed corner is about 8 μm or less. It is also possible to form the groove 3 serving as a nozzle by excimer laser processing after forming the outer shape portion. The corners of the obtained top plate are irradiated with laser light of the first pattern in an amount corresponding to a predetermined energy for processing the recess. The first pattern has a schematic shape shown in FIG. 13A, and communicates with the region in the X direction in which the groove is provided to form the recess a.
= 11 to 12 μm, a1 = 10 μm, and b = 5 μm (FIG. 7B).

At the time of processing the recess, it is necessary to remove a fillet and a chamfered shape at least at the E portion.
1 Set the shape such as dimensions. Preferably, the end surface of the recess 10 on the groove 3 side does not reach the end surface of the E portion on the groove 3 side,
Moreover, the shapes such as a1 and b dimensions are set so that the recesses 10 do not reach the individual orifice passages 8. In consideration of the fact that the E portion needs strength to withstand the pressure of pressure welding after the top plate is joined, it is more preferable that the a1 dimension has a defect on the joining surface 9 of the E portion such as a fillet at the corner G or a chamfered shape. Is set to the minimum value that can be removed. With the above, the formation of the groove and the recess, which will be the nozzle, is completed. It should be noted that a method of performing mechanical cutting with a dicing device or a resin processing cutter may be considered when the recess is additionally processed.

Next, for forming the orifice passage 8 along the groove 3 and opening the orifice 4, the second portion of FIG.
The pattern 112 is irradiated with laser light. The central axis of the orifice passage 8 is provided inside the groove 3 with a height of about 30 μm and an inclination angle of 10 °, the orifice 4 is opened with φ30 μm, and the recess 10 does not communicate with the orifice passage 8. If the b dimension of the recess is so large that the recess 10 reaches the passage 8, there is a risk of leakage of ink from the orifice passage 8, which is not preferable. According to the above procedure, FIG.
Processing of the top plate is completed as shown in (c).

The top plate according to the present embodiment can obtain a predetermined OH distance with respect to the substrate for obtaining the ink ejection performance, and a preferable bonding without forming a gap as shown in FIG. 3 (c). Is possible. In FIG. 7D, the top plate and the substrate are joined so that the ridge H of the substrate is located near the imaginary line of the corner G of the top plate. Alignment of both such as management of OH distance is achieved by image processing. After joining the top plates, as shown in FIG. 7D, even if a gap is formed between the orifice plate 6 and the end face F of the substrate 1, the relative position between the substrate 1 and the top plate 2 such as the OH distance becomes a predetermined value. Keep, E on the top plate 2
The part may be bonded to the substrate. This is because, unlike the gap shown in FIG. 3C, ink leakage between adjacent nozzles does not occur.

It is also conceivable to fill and seal the gap with a sealing agent such as silicon after joining the top plate. The dimension a of the recess 10 may be determined based on the amount of warpage deformation of the top plate 2 measured in advance in the X direction. That is, as shown in FIG. 4, if the range of the warp deformation in the X direction at the corners of the top plate 2 is ΔY, the a dimension of the recessed part due to the post-processing on the top plate is set to be a ≧ ΔY. As a result, at the positions of X1 and X2 in FIG. 4 where the warp amplitude is maximum, the E portion of the top plate 2 is always bonded on the substrate as shown in FIGS. It is possible to prevent ink leakage due to defects. That is, it becomes possible to secure a greater degree of freedom in joining the top plate and the substrate against the warp deformation of the top plate in the X direction. When the warp deformation of the top plate in the X direction is very small, the F
It is also conceivable to secure the OH distance with the surface abutting the orifice plate 6. As a result, the alignment of the top plate and the substrate in the Y direction can be simplified.

In the present embodiment, the X-axis cross section of the concave portion 10 to be formed has a rectangular shape. However, it is not necessary to limit the cross section to a rectangular shape as long as it does not hinder the preferable bonding state between the substrate and the top plate. Instead, it may have a triangular shape or the like. In addition, the cross-sectional shape may change along the X axis, including the range of the arrangement of the nozzles that eject droplets in the X direction. In this embodiment, the virtual line of the corner G is arranged on the side surface of the recess 10. However, as shown in FIG. 14, the recess may be provided so that the virtual line is included in the range of the size a of the recess. Conceivable.
This is an effective measure to absorb the dimensional tolerances of the two parts and the alignment tolerances in the joining process.

[Second Embodiment] FIGS. 9 and 10 show the structure of a top plate according to a second embodiment of the present invention. In this embodiment,
Of the region along the X axis where the ridge H of the substrate 1 is joined,
Different concave shapes are used in the arrangement range of the nozzles for ejecting liquid droplets and the other range. FIG.
The I-I part is the range in which the groove 3 serving as the nozzle is provided, and the JJ part is the range in which the groove is not provided. FIG. 10A shows a cross-sectional shape of the I-I portion, and FIG. 10B shows a cross-sectional shape of the JJ portion.
Preferable substrate positions at the time of bonding while maintaining a predetermined OH distance are indicated by a two-dot broken line.

In this embodiment, except for the area where the grooves are provided,
As shown in the JJ cross section of FIG. 10B, the second concave portion is provided so that a predetermined OH distance can be obtained when the end surface F of the substrate 1 is abutted against the surface of the concave portion on the orifice plate 6 side to be joined. 102 shapes are provided. At this time, the predetermined O
The shape of the first concave portion 101 is provided so that the end face F does not hit the top plate 2 in the arrangement range of the groove 3 when the H distance is obtained. According to the above configuration, at the time of joining the top plates, the end face F of the substrate 1 is brought into contact with the surface of the recess 102 of the top plate on the side of the orifice plate 6 so that the alignment in the Y direction can be easily performed.

[Embodiment 3] FIG. 11 shows a structure of a top plate according to Embodiment 3 of the present invention. When the thickness of the orifice plate is very small or the EL length is small, it is considered that the strength around the corner is reduced by providing the recess. By providing a recess as shown in FIG. 5 in this portion, the strength around the corners is further reduced, and there is a risk of breaking the top plate. In this embodiment, the recesses are intermittently arranged in the X direction to reduce the reduction in strength of the top plate due to the formation of the recesses. In FIG. 11, the recesses 10 are arranged at the same pitch as the grooves 3 corresponding to the portions 12 that will be the nozzle walls. For example, when polysulfone is used as the molding material for the top plate,
When b = 5 μm, the space between the recesses 10 is set to about several μm, the fillet shape between the individual recesses 10 is crushed by the ridges of the substrate, and a part of the crushed resin escapes to the recesses. As a result, good joining was achieved. Further, when disposing the above-mentioned recesses intermittently in the X direction, it is also effective to displace the disposing position in the Y direction as shown in FIG.

[0021]

As described above, according to the present invention, one or more recesses are provided at the corners formed at the intersections of the joint surfaces of the second member and the plate member, and First
By joining the ridge which becomes the one end face of the member so as to be positioned in the vicinity of the recess of the second member, ink can be ejected regardless of the accuracy of the edge shape such as the fillet shape of the corner at the time of manufacturing the top plate. It is possible to secure a preferable distance between the heater and the orifice, and it is possible to achieve stable ejection performance of ink and further reduce variations in ejection performance of individual inkjet heads. Also, by joining the first member and the second member in a good state due to the preferable positional relationship, both can be closely joined, and an inkjet head without crosstalk can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of the structure of a conventionally known inkjet head.

FIG. 2 is a diagram illustrating a structure on a joining surface side of a top plate.

FIG. 3 is a diagram for explaining a state when the top plate and the substrate are joined.

FIG. 4 is a diagram illustrating a configuration of a top plate according to the first embodiment of the present invention and a warp deformation of the top plate.

FIG. 5 is an enlarged view of a portion A in FIG. 4;

FIG. 6 is a sectional view taken along the line CC of FIG. 5;

FIG. 7 is a diagram illustrating an example of a manufacturing process in which a top plate of the present invention is provided with a recess.

FIG. 8 is a diagram illustrating a state in which the top plate according to the first embodiment of the present invention is bonded onto the substrate at a location where the warp amplitude is maximum.

FIG. 9 is a diagram showing a configuration of a top plate according to a second embodiment of the present invention.

10 (a) is a sectional view taken along line I-I of FIG.
(B) is a figure which shows the JJ cross section of FIG.

FIG. 11 is a diagram showing a configuration of a top plate according to Example 3 of the present invention.

FIG. 12 is a diagram showing another configuration of the top plate according to the third embodiment of the present invention.

FIG. 13 is a light-shielding pattern used in an example of the present invention.

FIG. 14 is a diagram showing another form of the recess according to the first embodiment of the present invention.

[Explanation of symbols]

 1 Substrate 2 Top Plate 3 Groove 4 Orifice 5 Dust 6 Orifice Plate 7 Heater 8 Orifice Passage 9 Joining Surface of Top Plate 10 Recess

Claims (8)

[Claims] 1. A first member having an energy generating means, and a second member joined to the first member, the nozzle groove having a nozzle for ejecting ink by the energy generating means. An ink jet head is provided with an orifice for ejecting ink from the ink jet head, and a second member having a plate portion forming a line of intersection with the joint surface with the first member. An inkjet head, wherein one or more recesses are provided at a corner formed at the intersection of the joint surfaces. 2. The first member and the second member have a ridge portion that is one end face of the first member and is substantially parallel to the arrangement direction of the energy generating means in the first member, The inkjet head according to claim 1, wherein the inkjet head is joined so as to be located in the vicinity of the recess. 3. The ink jet head according to claim 1, wherein the recess is formed such that its dimension is based on a warp deformation amount predicted in advance in the second member. 4. The recess has a ridge portion which is one end surface of the first member and is closer to the recess of the second member than the nozzle groove disposition range in a range other than the nozzle groove disposition range. The ink jet head according to any one of claims 1 to 3, wherein the ink jet head is formed. 5. The ink jet head according to claim 1, wherein the recess is formed intermittently. 6. A first member having an energy generating means and a second member joined to the first member, the nozzle groove having nozzles for ejecting ink by the energy generating means. An ink jet head manufacturing method comprising: an orifice for ejecting ink from the first member; and a second member having a plate portion that forms a line of intersection with the joint surface with the first member. A method for manufacturing an inkjet head, characterized in that one or more recesses are formed in a corner formed at an intersection of a plate portion and the joining surface before joining the first member and the second member. 7. The method of manufacturing an ink jet head according to claim 6, wherein the recess is formed before or after manufacturing the second member. 8. The straightness of the concave portion in the arrangement direction of the nozzle groove is Δy at least in the range where the nozzle groove is arranged, and the arrangement of the concave portion with respect to the Δy is defined as Δy. The method for manufacturing an inkjet head according to claim 6 or 7, wherein when the width in the direction orthogonal to the installation direction is a, the relationship between the two is formed such that a ≧ Δy. .