The present invention relates to a liquid ejecting head for ejecting liquid by externally applying energy to the liquid and a manufacturing dimension control method of the liquid ejecting head.
As a nozzle manufacturing method of an ink jet recording head, particularly a thermal ink jet recording method for ejecting ink through bubble generation by heating the ink, there have been conventionally used a method of laminating a resin material on a silicon substrate (silicon wafer) and a method of applying a nozzle plate onto the silicon substrate. In both methods, after nozzle formation, the silicon substrate has been cut by a dicer to be separated into respective chips.
In these days, similar liquid droplets of ink are desired in order to realize a high image quality. It has been known that delicate variation of a nozzle dimension during manufacturing has an influence on ejection and by extension on an image quality. Thus, in a situation such that the high image quality is desired, in the method of applying the nozzle plate onto the silicon substrate, dimensional tolerance such as a vertical or front-rear warp of the nozzle plate or insufficient application accuracy has an influence on ejection stability and an amount of ejection. Therefore, as the nozzle manufacturing method, as described in U.S. Pat. No. 6,139,761, the method of laminating the resin material on the silicon substrate becomes dominant. Further, in order to realize the smaller liquid droplets and the stable ejection for the purpose of a higher image quality, such a need that a nozzle dimension control method is intended to be strictly adopted has been increased more than ever before.
As a nozzle dimension measuring method for filling such a need, two methods have been principally known. One method is such that a microscope is used to observe a liquid ejection port from above a nozzle forming member to measure a nozzle dimension. The other method is such that a TEG chip (a chip for inspecting a nozzle shape) or a non-defective chip is pulled out and the nozzle dimension is measured from its cutting plane.
However, these conventional nozzle dimension measuring methods have been accompanied with the following problems. First, in the observation method through the microscope from above, in the case where a tapered shape with respect to a substrate thickness direction (Z direction) is to be observed, there arises such a problem that a position of an edge of a nozzle shape pattern with respect to a horizontal direction (X direction and Y direction) of a substrate surface is detected so as to vary depending on a focus position. For this reason, measurement accuracy is low, so that the method cannot sufficiently fill the need for dimension measurement accuracy at a high level which has been required in recent years.
On the other hand, in the cutting plane inspection of the pulled out TEG chip or non-defective chip, the dimension measurement accuracy is higher than that of the above observation method but involves the following three problems.
A first problem is such that the cutting plane inspection is a destructive inspection in which the TEG chip or the non-defective chip is cut, thus resulting in an increased cost. A second problem is such that a cutting step is an additional step to complicate a manufacturing method, thus increasing a production cost. A third problem is such that the number of inspection points for enhancing the measurement accuracy cannot be increased. That is, when the number of inspection points for enhancing the measurement accuracy is increased, an available chip number per (one) wafer is decreased to result in a considerable increase in cost, so that the inspection points have to be actually limited to several points on the wafer. As a result, dimensional variation on the wafer cannot be accurately kept track of, thus lowering the measurement accuracy.
In view of the above-described problems, a principal object of the present invention is to improve dimension measurement accuracy of a nozzle.
Another object of the present invention is to reduce a cost in a manufacturing dimension control step of the nozzle.
According to an aspect of the present invention, there is provided a liquid ejecting head comprising:
a substrate;
a nozzle forming member for forming on a principal surface of the substrate a nozzle comprising a flow passage of liquid and an orifice for ejecting the liquid; and
a dummy pattern,
wherein the dummy pattern has substantially the same dimension as at least a part of the nozzle and is formed so that a cross section of the dummy pattern is exposed at an end surface of the nozzle forming member.
According to the present invention, it is possible to improve the dimension measurement accuracy of the nozzle and also to reduce the cost in the manufacturing dimension measurement accuracy of the nozzle.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
Hereinbelow, embodiments of the present invention will be described with reference to the drawings. In the following description, as the liquid ejecting head of the present invention, an ink jet recording head is described as an example but the present invention is not limited thereto.
Referring to
The liquid ejecting head 17 introduces an electric signal externally inputted through electrical contacts 16 of the electric circuit substrate 15 into the chip 4, mounted on the liquid ejecting head 17, through the flexible circuit substrate 12.
The chip 4 includes, as shown in
The liquid to be ejected from the chip 4 is supplied from an unshown liquid retaining container via the supply port 11 and branches off into the plurality of orifices 6. Then, the liquid in the neighborhood of the heater 10 causes film boiling by heating the heater 10 by thermal energy depending on the electric signal from the electric circuit substrate 15, thus being gasified. The liquid is ejected from the orifice 6 by kinetic energy due to the gasification.
Here, the flow passages 7 and the orifices 6 constitute the nozzles 5 (
Next, a manufacturing process of the chip (nozzle chip) 4 as a constituent element of the liquid ejecting head 17 will be described. The liquid ejecting head 17 is provided with a nozzle group consisting of a plurality of nozzles for ejecting the liquid.
First, as shown in
Next, as shown in
Next, a resin material constituting a mold for a liquid flow passage (hereinafter referred to as a “mold”) is applied onto the substrate 20, followed by light exposure and development. As a result, as shown in
Then, as shown in
Next, as shown in
Thereafter, the back surface of the silicon substrate 20 is subjected to plasma dry etching with CF4 or the like to remove the film (layer) of silicon oxide or silicon nitride corresponding to the ink flow passage mold 22 to cause an ink supply port 11 to penetrate through the substrate 20 as shown in
Then, the nozzle protecting material 25, which is no longer needed, is removed to create a state shown in
The above-described steps are a series of steps until the nozzle 5 and the nozzle dummy pattern 26 are prepared on the silicon substrate 20. Thereafter, the silicon substrate on which the nozzle 5 and the nozzle dummy pattern 26 are formed (hereinafter referred to as a “nozzle substrate”) is cut along a plurality of scribe lines 2 provided at predetermined positions to obtain chips 4 (
The nozzle dummy pattern 26 is prepared by the above-described manufacturing method, so that the nozzle dummy pattern 26 has substantially the same dimension as the nozzle 5 and includes a plurality of nozzle dummy pattern portions provided along the scribe lines 2 of the nozzle forming member 9. Then, by the cutting along the scribe lines 2, the plurality of nozzle dummy pattern portions 26 is exposed at a cross-section thereof as shown in
As described above, in the present invention, a structure having the same dimension as a dimension of the flow passage as a part of the nozzle is provided along the scribe line (cutting line) and design is made so that a cutting plane of the structure is exposed by cutting, so that it is possible to easily and inexpensively perform nozzle cross-section observation with high accuracy. Specifically, the TEG chip which has been conventionally required for the cross-section observation can be eliminated to result in a reduced cost. Further, in the case of measuring the dimension through the conventional nozzle cross-section observation, the cutting step as an additional step can be eliminated, so that a manufacturing cost can be reduced. Further, even in the case of an occurrence of a problem, any chip can be measured in a nondestructive manner, so that quality control accuracy is also improved.
In this embodiment, the dummy pattern 26 before the cutting of the nozzle substrate has a shape having substantially the same constitution as an orifice 6 as a part of the nozzle (hereinafter referred to as an “orifice dummy pattern 26A”). The orifice dummy pattern 26A roughly has a circular truncated cone-like shape, so that the shape of the cross-section exposed portion of the orifice dummy pattern 26A varies depending on a position in which the nozzle forming member 9 is cut.
That is, a taper angle appearing in a cutting plane in the case where the cutting plane is deviated from a center line of the orifice portion is larger than that in the case where the cutting plane is aligned with the center line of the orifice portion. Therefore, when an arrangement direction of many orifice dummy patterns 26A is non-parallel with the scribe line 2, even in the case of a varying cutting position, there is some orifice dummy pattern 26A with a cutting plane substantially aligned with the center line of the orifice portion.
By utilizing this fact, as shown in
During the cutting of the nozzle substrate, a normal taper angle appears in the case where the cutting plane is aligned with the center line of the orifice position. Therefore, of several orifice dummy patterns 26A appearing in the cutting plane, an orifice having the smallest taper angle is selected and subjected to measurement, so that it is possible to measure the taper angle with high accuracy.
For example, in
As described above, by arranging the plurality of dummy patterns on the cutting line in a non-parallel manner and appropriately selecting a dummy pattern to be measured from the plurality of dummy patterns, it is possible to perform a shape observation and dimension measurement of a desired nozzle with accuracy. Particularly, it is possible to perform high-accuracy measurement even with respect to such a shape that a cross-section varies depending on the cutting position as in the case of the orifice dummy patterns described in this embodiment.
Each orifice 6 in this embodiment is formed in a multi-stepped portion-like shape at an opening-side surface as shown in
On the other hand, the dummy pattern 26 before the cutting of the nozzle substrate has a shape having substantially the same constitution as the multi-stepped portion-like orifice 6 as a part of the nozzle (hereinafter referred to as an “orifice dummy pattern 26B”). The orifice dummy pattern 26A has such a multi-stepped portion-like shape, so that the shape of the cross-section exposed portion of the orifice dummy pattern 26B varies depending on a position in which the nozzle forming member 9 is cut.
In this embodiment, as shown in
During the cutting of the nozzle substrate, a normal multi-stepped portion-like shape appears in the case where the cutting plane is aligned with the center line of the orifice position. Therefore, of several orifice dummy patterns 26B appearing in the cutting plane, an orifice having a shape closest to the normal multi-stepped portion-like shape is selected and subjected to measurement, so that it is possible to measure the taper angle with high accuracy.
For example, in
According to this embodiment as described above, it is possible to exercise dimension control with respect to the multi-stepped portion-like orifice 6 which was less measurable due to a difference in refractive index between the ambient air and the nozzle forming member 9 in the case of microscope observation from above the nozzle forming member 9.
That is, as described above, in the present invention, the dummy pattern having substantially the same dimension as the nozzle is provided on the scribe line and is disposed so that a cutting plane by cutting (scribing) is exposed. Further, the array of the dummy patterns is disposed so as to be non-parallel with the scribe line (cutting line). As a result, the present invention can achieve the following three effects. It is possible to perform measurement with accuracy even with respect to a cross-sectional shape varying depending on the cutting position. It is possible to perform measurement with reliability even when the cutting line varies. It is possible to measure even a position in which it was difficult to perform measurement in microscope observation from above the nozzle forming member.
In the above-described Embodiments, the ink jet recording head for ejecting ink droplets by causing the ink to generate bubbles and heat is employed. However, the present invention is not limited thereto but is also applicable to liquid ejecting heads in general capable of ejecting liquid in the form of a droplet.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purpose of the improvements or the scope of the following claims.
This application claims priority from Japanese Patent Application No. 315820/2007 filed Dec. 6, 2007, which is hereby incorporated by reference herein.
Number | Date | Country | Kind |
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2007-315820 | Dec 2007 | JP | national |
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Number | Date | Country |
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402165962 | Jun 1990 | JP |
Number | Date | Country | |
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20090147050 A1 | Jun 2009 | US |