JP2007062297A - Liquid discharging head and method for manufacturing liquid discharging head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid discharging head having good recording quality by improving the working precision of a liquid supply aperture. <P>SOLUTION: This liquid discharging head has a substrate 1 formed on the surface of a heating resistor as a discharging energy generating element and a flow passage constituting member which forms a discharging aperture 7 and a liquid flow passage 8 communicating with the discharging aperture 7. In addition, a liquid supply aperture 9 for supplying a liquid to the liquid flow passage 8, is formed on the substrate 1. The liquid supply aperture 9 is an oval hole which is cut by a blade of a dicing saw way through the substrate 1 and has an inner wall, at both ends in the longitudinal direction, formed of an inclined face 17 along an outer peripheral arced surface in a working position by a blade cutting deep into the inner wall. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid discharge head that discharges liquid droplets using discharge energy generated by a discharge energy generating element, and a method for manufacturing the liquid discharge head.

  The ink jet recording head manufacturing method includes the following steps, for example. From a process of forming a heating resistor and a driver element for passing current to a substrate such as a silicon wafer, a nozzle forming process of forming a nozzle for ejecting ink, and a mounting process for mounting on an ink jet recording apparatus Become.

  4A and 4B show a basic configuration of the ink jet recording head disclosed in Patent Document 1. FIG. 4A is a schematic partial plan view, and FIG. 4B is a schematic cross-sectional view taken along line AA in FIG. .

  In the ink jet recording head of this example, the following layers are sequentially formed on a substrate 100 made of a silicon wafer or the like. For example, an insulating heat storage layer 102 made of a thermal oxide film, a heating resistor layer 103, an electrode wiring layer 104, an ink resistant layer (first protective layer) 105, a cavitation resistant film (second protective layer) 106, and the like are formed. Has been. These are all thin films formed by sputtering or the like and patterned by a photolithography technique or the like.

  Furthermore, the liquid flow path layer 111 and the orifice plate 110 are sequentially joined thereon, and the external electrical signal connection is connected by wire bonding or TAB to obtain a thermal ink jet recording head.

  In this thermal ink jet recording head, ink is supplied from the ink supply port 109 provided on the substrate to the liquid passage 108 and heat is generated in the heating resistor layer 103 to generate bubbles in the ink. Ink droplets are discharged from the provided discharge port 107.

The ink supply port 109 is formed by processing a glass substrate, a Si substrate, or the like by a sandblasting method, and a minimum width processing surface 114 and a maximum width processing surface 115 are generated due to processing errors.
JP 2001-341314 A

  In the sandblasting method disclosed in Patent Document 1, since the processing surface is rough, the etching surface is newly processed to make the processing surface smooth, or the ink-resistant coating material is applied. Become high.

  In addition, the sandblasting method has low processing accuracy, and sandblasting is performed in advance in consideration of processing errors. However, when sandblasting is performed in consideration of processing errors, the distance from the opening of the ink supply port to the heating resistor increases.

  In such an ink jet recording head, the refill speed is slow and the printing speed cannot be increased. The term “refill” means that the ink is filled in the entire liquid passage and the ejection port after ink ejection, and this refill time greatly affects the printing speed of the printer. In other words, even if the drive frequency is increased, if the refill does not catch up, the heating resistor layer will generate heat in the absence of ink or in a state where there is little ink. Printing is unclear. In order to increase the refill frequency, it is necessary to shorten the distance between the heating resistor layer and the ink supply port as much as possible. However, in the sandblasting process that allows for processing errors as described above, the heating resistor and the ink supply port It is difficult to sufficiently shorten the separation distance.

  Further, the processing by sand blasting has a drawback that the processing cross section is rough and bubbles tend to accumulate. This bubble accumulation is good when it is small, but adjacent bubble accumulations may be combined into larger bubbles. In that case, there is a possibility that the ink supply port is partially narrowed due to the bubble accumulation partially, and sufficient ink supply is not performed.

  When such a phenomenon occurs, a phenomenon in which ink is not ejected from the ejection port occurs, and printing becomes unclear or white spots occur.

  On the other hand, anisotropic etching is a processing method with a small processing error. This anisotropic etching has relatively good processing accuracy because the etching proceeds along the crystal orientation, but has a drawback that the etching angle is large and the processing area of the back surface is large because the etching is performed along the crystal orientation. . In addition, etching defects may occur partially due to crystal defects in the Si substrate. Since there are variations depending on the production lot of the Si substrate, it is necessary to confirm the etching state in advance every time the lot changes. In addition, expensive capital investment is required.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a liquid discharge head with improved recording quality by improving the processing accuracy of the liquid supply port.

  In order to achieve the above object, a liquid discharge head according to the present invention includes a substrate having a discharge energy generating element formed on a surface thereof, a discharge port bonded to the surface of the substrate, and a liquid channel connected to the discharge port. A liquid discharge head in which a liquid supply port for supplying a liquid to the liquid flow path is formed on the substrate. The liquid supply port is formed by a blade of a dicing saw. A long hole penetrating through the substrate cut into the substrate, wherein inner walls at both ends in the longitudinal direction of the long hole are formed of inclined surfaces that follow an outer peripheral arc surface at the cutting position of the blade. And

  The method of manufacturing a liquid discharge head according to the present invention forms a substrate having a discharge energy generating element formed on the surface thereof, a discharge port joined to the surface of the substrate, and a liquid flow path communicating with the discharge port. A liquid discharge head having a liquid supply port for supplying a liquid to the liquid flow path on the substrate, wherein the liquid supply port includes a blade of a dicing saw. It is characterized by being formed using.

  Since this invention is comprised as mentioned above, there exists an effect as described below.

  There is no variation in processing accuracy, and the width of the opening of the liquid supply port becomes constant near the discharge energy generating element, so that the variation in refill time between the discharge ports is reduced and the recording quality and drive frequency are improved. Furthermore, since the roughness of the processed surface is reduced and the bubbles are less likely to stay, the occurrence of non-ejection due to the bubbles is reduced.

  Since the dicing saw is an indispensable facility for manufacturing the liquid discharge head, the existing facility can be used. As a result, there is no need for expensive equipment investment such as newly providing a sandblasting process line or an anisotropic etching line, and the manufacturing cost can be reduced.

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

  1A and 1B show a main part of a liquid discharge head according to an embodiment. FIG. 1A is a schematic plan view of a back surface side of a substrate on which a liquid supply port is formed, and FIG. 1B is along the line AA in FIG. It is a schematic cross section.

  First, the insulating heat storage layer 2 made of an oxide film or the like is formed on the surface of the substrate 1 made of a silicon wafer. This may be formed by sputtering or the like, or a thermal oxide film may be formed on a silicon wafer. Then, a heating resistor layer is formed thereon by sputtering or the like, and an electrode wiring layer such as Al is further formed thereon by sputtering or the like. Next, the electrode wiring 4 and a heating resistor (not shown) as a discharge energy generating element are patterned by photolithography. On top of this, a liquid-resistant layer 5 made of SiN or the like is formed by sputtering or the like, and a cavitation-resistant film 6 made of Ta or the like is formed. After that, an adhesive layer for joining the orifice plate 10 having the flow passage walls 11 and the discharge ports 7 which are flow passage constituting members is formed.

  Next, the liquid supply port 9 is formed in the substrate 1, and the processing of the liquid supply port 9 is performed by cutting with a dicing saw from the back side of the substrate 1 on which the ejection energy generating element is not provided. At this time, the liquid supply port 9 must be accurately passed through the surface of the substrate 1 on which the heating resistor is formed.

  Therefore, a photoresist is applied to the back surface of the substrate 1, and a liquid supply port alignment mark is exposed on the back surface by an exposure machine that can be formed at the same position as the front surface, and development is performed for patterning. At this time, it is preferable to perform patterning so as not to leave a photoresist in a portion where the liquid supply port 9 is processed. This is to reduce clogging of the blade 14 due to the resist and keep a good cutting state.

  Since the liquid supply port 9 is formed by penetrating the substrate 1, it is necessary to take a larger cut amount of the disc-shaped blade 14 of the dicing saw than the thickness of the substrate 1. FIG. 2 shows an example of determining the cutting amount (z).

  In FIG. 2, (L) is a dimension in the longitudinal direction of the liquid supply port 9, and (L / 2) is a half of the dimension. Since (L / 2) and the blade radius (r) are known, the angle (a) is obtained by a trigonometric function. If the angle (a) is known, (y) can be calculated by L / 2 × tan (a), and the difference between the blade radius (r) and (y) is the cutting amount (z).

  Here, cutting is performed only in the vertical direction, and no horizontal feed is performed.

  In this case, the inclination angle (b) of the inclined surface 17 of the inner wall at both ends in the longitudinal direction of the liquid supply port 9 on the substrate surface 12 varies depending on the cutting depth (z) of the blade. That is, the inclination angle of the tangent line of the arc of the blade that abuts (processes) the inclined surfaces 17 of the inner walls at both ends in the longitudinal direction. If the blade cutting depth (z) increases, the inclination angle (b) increases, and if it decreases, the inclination angle (b) decreases.

  In the case of a multi-nozzle such as an inkjet line printer, the longitudinal dimension of the liquid supply port 9 is larger than the diameter of the blade. In that case, as shown in FIG. 3, the center 15 of the blade 14 is moved by a distance (x) in the horizontal direction.

  The lateral dimension (width) of the liquid supply port 9 depends on the thickness of the blade 14. However, when there is no blade having a thickness corresponding to the required width of the liquid supply port, for example, in the case of 75 μm width, a 50 μm-thick blade is used, cutting at 50 μm for the first time, and the liquid supply port width for the second time Cut by 25 μm in the direction.

  In the present invention, the liquid supply port 9 is a long hole that penetrates the substrate 1 cut into the substrate 1 by a blade 14 of a dicing saw. Then, the inner walls at both ends in the longitudinal direction of the long hole are inclined in accordance with the outer arc surface at the processing position of the blade 14 that is cut (the outer arc surface of the blade 14 in contact with the inner walls at both ends in the longitudinal direction). It consists of surface 17.

  As described above, by using an existing dicing saw, the liquid supply port can be processed with high accuracy, so that the processing margin can be reduced. As a result, the liquid flow path can be shortened, and the refill frequency can be increased. In particular, the present invention provides an excellent effect in a liquid discharge head of a liquid discharge recording method in which flying droplets are formed using thermal energy and recording is performed. Further, since the existing equipment is used, it is not necessary to make a new capital investment, and the liquid discharge recording head can be provided at a low cost.

  Note that the present invention is not limited to the above-described substrate made of a silicon wafer, and any substrate other than a silicon wafer that can be diced can be applied.

  Example 1 of the present invention will be described.

  First, a heat storage layer made of a thermal oxide film having a thickness of 3.0 μm was formed on the surface of the substrate 1 made of a silicon wafer. A heating resistor layer made of TaN was formed thereon by sputtering. Further thereon, an electrode wiring layer made of Al was formed by sputtering. Next, the electrode wiring 4 and the heating resistor were patterned by photolithography. A liquid resistant layer 5 made of SiN was formed thereon by sputtering, and a cavitation resistant film 6 made of Ta was further formed and patterned.

  Next, as shown in FIG. 1B, the liquid supply port 9 is opened. The opening width is 100 μm and the opening length is 22 mm.

  In order to open the liquid supply port 9, the position of the liquid supply port 9 opening on the substrate surface and the processing position on the back surface of the substrate must be accurately matched. Therefore, a liquid supply port alignment mark prepared in advance for the substrate surface is patterned at the same position on the back surface of the substrate. Patterning was performed using a backside exposure machine (UX4023-SC manufactured by USHIO INC.).

  Next, in order to penetrate the substrate 1 in the thickness direction by the disc-shaped blade 14 of the dicing saw, the substrate 1 was fixed to the set plate in which the groove for blade penetration was processed with the back surface facing up.

  The cutting depth (z) of the blade 14 was L / 2 = 11 mm, the blade radius was 25 mm, the angle (a) was about 63.8 °, and y = 22.35 mm, so that it was 2.65 mm.

  In the liquid discharge recording head manufactured in this way, the roughness of the processed surface of the liquid supply port of the substrate is reduced. In addition, since the inner walls at both ends in the longitudinal direction are inclined surfaces that follow the outer peripheral arc surface at the cut blade processing position, bubbles are less likely to stay.

The main part of the liquid discharge head by one embodiment of the present invention is shown, (a) is a schematic plan view from the back, and (b) is a schematic sectional view which meets an AA line of (a). In this invention, it is explanatory drawing which shows an example of how to obtain | require the cutting amount of a blade. In this invention, it is explanatory drawing of the processing method corresponding to the increase in the longitudinal direction processing dimension of a liquid supply port. 1 shows an inkjet recording head according to a conventional example, in which (a) is a schematic partial plan view, and (b) is a schematic cross-sectional view taken along the line AA of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Insulation heat storage layer 4 Electrode wiring 5 Liquid-resistant layer 6 Cavitation-resistant film 7 Discharge port 8 Liquid flow path 9 Liquid supply port 10 Orifice plate 11 Flow path wall 12 Substrate surface 13 Processing position 14 Blade 15 Center 16 Bubble 17 Inclined surface

Claims (5)

A substrate having a discharge energy generating element formed on a surface thereof, a discharge port bonded to the surface of the substrate, and a flow path forming member that forms a liquid flow path communicating with the discharge port; In the liquid discharge head in which the liquid supply port for supplying the liquid to the liquid flow path is formed,
The liquid supply port is a long hole that penetrates the substrate cut into the substrate by a blade of a dicing saw, and inner walls at both ends in the longitudinal direction of the long hole are outer peripheries at the processing positions of the cut blade. A liquid discharge head comprising an inclined surface following an arc surface.   2. The liquid discharge head according to claim 1, wherein the liquid supply port has a longer length in a longitudinal direction on a back surface side than a front surface side of the substrate.   3. The liquid discharge head according to claim 1, wherein the liquid supply port has a short-side dimension larger than a thickness of the blade. A substrate having a discharge energy generating element formed on a surface thereof, a discharge port bonded to the surface of the substrate, and a flow path forming member that forms a liquid flow path communicating with the discharge port; A method of manufacturing a liquid discharge head in which a liquid supply port for supplying a liquid to a liquid flow path is formed,
The method of manufacturing a liquid discharge head, wherein the liquid supply port is formed using a blade of a dicing saw.   5. The liquid according to claim 4, wherein the liquid supply port is formed in the substrate by cutting a blade of the dicing saw from a surface side of the substrate on which the discharge energy generating element is not provided. Manufacturing method of the discharge head.

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