JP2888474B2 - Manufacturing method of inkjet head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet head, and more particularly to a cutting process for defining an ink flow path length with high precision and forming a high quality nozzle opening. It is.

[0002]

2. Description of the Related Art A variety of methods have been proposed for manufacturing an ink jet head. As a method useful in mass production, cost reduction, and quality stabilization, a large number of heads are formed on a large area substrate. A method of cutting and separating has been considered. In particular, a manufacturing method of obtaining a large number of uniform inkjet heads by bonding and dicing two Si wafers is a very useful method in mass production, cost reduction, and quality stabilization. Such a production method is described in, for example, JP-A-61-230954,
It is described in JP-A-1-166965 and the like.

As a technique common to such a method of manufacturing an ink jet head, dicing (cutting) is used to cut out the ink jet head.
At this time, in many ink jet head structures, dicing is used to process / form a nozzle surface and a nozzle opening which greatly affect the ink droplet ejection directionality, and at the same time, the ink flow path length which greatly affects the ejection characteristics, particularly the ink droplet volume. Is determined. Therefore, various proposals have been made for dicing methods.

For example, in the technique described in Japanese Patent Application Laid-Open No. 60-196354, the cutting step is performed in two or more stages in accordance with the constituent material of the head. Japanese Patent Application Laid-Open No. 2-184451 discloses a method of performing dicing with a peripheral speed determined by a diameter and a rotation speed of a blade used in dicing being fixed or higher. Japanese Patent Application Laid-Open No. 5-57897 describes a method in which a groove serving as a nozzle opening is formed before bonding substrates, and then the substrates are bonded and separated at the grooves. In Japanese Patent Application Laid-Open No. Hei 4-234666, after a resin layer portion at a nozzle opening portion is subjected to pattern etching in advance,
A method for joining and cutting substrates is described. Japanese Patent Application Laid-Open No. 4-234667 discloses that after a resin layer portion at a nozzle opening portion is subjected to pattern etching in advance, a groove portion is formed at a portion other than the resin layer portion to be a nozzle opening portion, and then the substrates are joined and separated at the groove portion. Are described. These techniques are intended to economically produce a head with good dimensional accuracy without missing nozzle openings.

[0005] As described above, the dicing process of the ink jet head affects the length of the ink flow path and the shape of the nozzle opening.
As a blade to be used, a resin blade obtained by coating a very fine diamond with a resin (resin) is generally used. However, this resin blade is soft and gradually deforms during the cutting process, causing an error in the cutting position.

In the technique described in Japanese Patent Application Laid-Open No. 60-196354, since cutting is simply performed in a plurality of times, a soft resin blade is used to obtain a high-quality discharge port. Therefore, the cutting position cannot be maintained with high precision over the cutting process of many lines. Also,
With the technique described in Japanese Patent Application Laid-Open No. 5-57897, high-quality and high-precision cutting can be achieved. However, if the two substrates are not bonded accurately, the upper or lower portion of the discharge port will be displaced, and ink will be displaced. Has an effect on the ejection direction of the ink. In particular, in a high density head such as 600 DPI,
Since this influence becomes a problem, a problem remains in the bonding technique.

After the resin layer portion of the nozzle opening portion disclosed in the above-mentioned JP-A-4-234666 and JP-A-4-234667 is pattern-etched in advance, the portion around the nozzle opening other than the resin layer portion is removed. In the dicing method, there is no cutting of the resin layer so there is no clogging of the blade, and there is no burr due to cutting in the resin layer,
Good discharge ports can be obtained. However, a displacement corresponding to the dicing position accuracy occurs between the end of the resin layer pattern-etched at the discharge port and the end of the substrate formed by cutting, and the discharge port has only the thickness of the resin layer. Step occurs. This step is a problem particularly in a high-density head such as 600 DPI, and a problem remains in dicing position accuracy.

In the technique described in Japanese Patent Application Laid-Open No. 2-184451, a high-quality discharge port can be initially obtained by defining the peripheral speed of the blade. However, when a large number of heads are obtained by dicing, there is a problem that the resin blade is gradually deformed as described above, and the quality and accuracy in the latter half are reduced. Further, the conditions for achieving the quality are greatly related to the cutting depth, the feed rate, and the supply of the grinding water, and it is difficult to specify only the peripheral speed of the blade.

[0009] Processing techniques other than the ink jet head are disclosed in JP-A-3-281170 and JP-A-4-257.
As described in, for example, Japanese Patent Publication No. 405, there is proposed a method in which a dress material is fixed in the vicinity of an object to be cut, and a cutting blade is dressed (dressed) while cutting to always achieve high cutting quality. ing. However, in these processing techniques, the dress material must be fixed at the same time as the work to be cut, and there is a problem in workability and cost.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to easily and accurately perform cutting and obtain a high-quality ink jet head. It is an object of the present invention to provide a method for manufacturing an ink jet head.

[0011]

According to the present invention, there is provided a method for manufacturing an ink jet head according to the first aspect, wherein the ink jet head includes an ink flow path and an ejection port connected to the ink flow path for ejecting ink droplets. A method of forming the discharge port and / or its peripheral surface by a cutting process using a rotary cutting blade, and / or defining an ink flow path length, wherein the cutting process is performed in the thickness direction of the workpiece. The region including the discharge port is divided into B, the upper region of the region B not including the discharge port is defined as A, and the relative feed speed of the rotary cutting blade to the workpiece in each region is V _B , V _{When A} is set, V _A > V _B is satisfied. Conditions of the relative feed speed can be a V _A ≧ 3 × V _B. In addition, area A
Can be further divided into multiple stages for cutting.

Further, in the method of manufacturing an ink jet head according to the present invention, in the ink jet head having an ink flow path and an ejection port for ejecting ink droplets connected to the ink flow path, diamond particles are hardened with resin. This is a method of cutting while rotating a resin-based cutting blade, wherein the number of rotations is P (rotation / sec), and the cutting blade radius is R.
(Mm), Cutting blade width: W (mm), Feed speed: V (mm
/ Sec), cutting depth: H (mm), cutting volume per unit area / unit time of cutting blade: U = V ×
H × W / (2 × π × R × P × W) is set to 0.9 × 10 ⁻⁵ (m
m ³ · sec / mm ² · sec) or more, including at least one cutting step mainly for cutting silicon.

According to a fifth aspect of the present invention, there is provided an ink jet head having an ink flow path and a discharge port for ejecting ink droplets connected to the ink flow path. In this method, the cutting conditions of the area mainly composed of silicon including the discharge port are changed by cutting the cutting blade while rotating the cutting blade per unit area / unit time: U is 1.4 ×.
The cutting is performed under a condition of less than 10 ⁻⁵ (mm ³ · sec / mm ² · sec).

According to a sixth aspect of the present invention, in the method of manufacturing an ink jet head according to the first aspect, when the object to be cut is mainly made of a silicon material, the region B is defined by the fifth aspect. The cutting is performed under the conditions shown, and the region A is cut under the conditions described in the fourth aspect.

According to a seventh aspect of the present invention, there is provided an ink jet head having an ink flow path and a discharge port for ejecting ink droplets connected to the ink flow path, wherein a resin system in which diamond particles are hardened by a resin is provided. In this method, the cutting volume per unit area / time: U is 1.9.
At least one cutting step mainly for cutting glass under the condition of × 10 ⁻⁶ (mm ³ · sec / mm ² · sec) or more.
It is characterized by including more than steps.

In the method of manufacturing an ink jet head according to the present invention, in the ink jet head provided with an ink flow path and a discharge port for ejecting ink droplets connected to the ink flow path, a resin system in which diamond particles are hardened with resin. In this method, the cutting conditions of a region mainly composed of a glass material including the discharge port are changed by setting the cutting volume per unit area and unit time of the cutting blade: U to 1.5.
The cutting is performed under the condition of less than × 10 ⁻⁶ (mm ³ · sec / mm ² · sec).

According to a ninth aspect of the present invention, in the method of manufacturing an ink jet head according to the first aspect, when the object to be cut is mainly made of a glass material, the region B is defined as in the eighth aspect. The cutting is performed under the conditions shown, and the region A is cut under the conditions described in the seventh aspect.

According to a tenth aspect of the present invention, in the method of manufacturing an inkjet head according to the first or sixth or ninth aspect, when the workpiece is divided into three or more steps in the thickness direction of the workpiece, Cutting volume per unit area and unit time of cutting blade in cutting process: U
The, B an area including the discharge port, when the upper region of the region B not including the discharge port and A, the lower region C of the region B not including the discharge port, U _C ≦ U _B <U _A is set.

In the method of manufacturing an ink jet head according to the present invention, an ink jet head having an ink flow path and an ejection port for ejecting ink droplets connected to the ink flow path is ground while rotating a rotary cutting blade. In the method for manufacturing a head, the grinding water does not directly contact the rotary cutting blade, and the grinding water is supplied to a grinding area of the rotary cutting blade via a grinding groove formed by the rotary cutting blade. It is characterized by having been done.

According to a twelfth aspect of the present invention, in the method for manufacturing an ink jet head according to the eleventh aspect, the supply angle of the grinding water is 0 to 45 with respect to the feed direction of the rotary cutting blade.゜.

In the method of manufacturing an ink jet head according to the present invention, when the grinding step divided in the thickness direction of the object to be ground is performed in the invention according to the first or sixth or ninth or tenth aspect, When the region including the discharge port is B, the upper region of the region B not including the discharge port is A, and the lower region of the region B not including the discharge port is C, at least the region B and the region C In the grinding step, the grinding is performed under the supply condition of the grinding water described in claim 11 or 12.

[0022]

According to the first to third aspects of the present invention, in the cutting step for determining the flow path end, the step is divided into multiple steps in the thickness direction of the work to be cut, and the cutting feed speed of the upper part is discharged. When the cutting feed speed is equal to or higher than the cutting feed speed in the region including the outlet, and preferably three times or higher, the process time can be shortened, that is, the throughput can be improved while maintaining the quality of the discharge port. At this time, by cutting the upper portion further into n pieces and cutting, the feed speed can be made n times or more, and the effect is further enhanced.

In order to stably process a plurality of heads with high quality and high precision, in the invention according to the fourth aspect, cutting conditions for sharpening the resin blade and correcting the shape are mainly determined by changing the silicon material. In the case of cutting, the cutting volume per unit area and unit time of the blade: U is 0.9 × 10
^-5 (mm ³ · sec / mm ² · sec) or more. In the invention according to claim 7, when mainly cutting glass material, the cutting volume per unit area and unit time of the blade: U is set to 1.9 × 10 ⁻⁶ (mm ³ · sec / m).
m ² · sec) or more. By performing cutting in a region that does not include the discharge port or in another location under these conditions, blade sharpening and shape correction can be performed during the process.

According to the fifth aspect of the present invention, the cutting conditions of the region including the discharge port are mainly set in the case of cutting a silicon material, the unit area of the blade and the cutting volume per unit time:
U is set to 1.4 × 10 ⁻⁵ (mm ³ · sec / mm ² · sec)
c) less than Further, in the invention according to claim 8, when mainly cutting glass material, the cutting volume per unit area and unit time of the blade: U is 1.5 × 10 ^−6.
(Mm ³ · sec / mm ² · sec). By cutting the area including the discharge port under these conditions, a highly accurate and high quality end face of the discharge port can be obtained.

In the invention according to claim 6 and claim 9, the discharge port surface is cut by multi-step cutting, and the upper region of the region including the discharge port is cut under the conditions described in claim 4 or claim 7, An area including the discharge port after cutting the area including the discharge port under the conditions according to claim 5 or 8 so as to sharpen the blade and correct the shape when cutting the upper area of the area including the discharge port. Can be cut with high precision, and a high quality discharge port can be obtained.

Further, in the invention according to claim 10,
In the multi-stage cutting of three or more stages, the cutting condition of the lower region is set to be smaller than the cutting condition of the upper region in terms of the unit area of the blade and the cutting volume per unit time: U. Secondary obstacles to the cutting surface can be prevented, and the yield can be improved.

According to the eleventh aspect of the present invention, the grinding water (cooling water) does not directly contact the rotary cutting blade, and the rotary cutting blade has a grinding groove formed by the rotary cutting blade. By supplying the water to the grinding area at the tip, the runout of the blade is suppressed and the grinding water is efficiently supplied to the grinding area, so that high-precision grinding can be performed and the nozzle quality is good. And uneven shape change of the tip of the blade hardly occurs. Further, as in the invention of the twelfth aspect, more preferable results are obtained when the supply angle of the grinding water is 0 to 45 ° with respect to the feed direction of the rotary cutting blade (the bottom surface of the grinding groove).

According to the thirteenth aspect of the present invention, when the grinding step divided in the thickness direction of the object to be ground is performed, at least a region including the discharge port and a region below the discharge port are formed. By grinding under the indicated grinding water supply conditions, highly accurate grinding can be performed,
High quality discharge ports can be obtained.

[0029]

FIG. 1 is a process diagram showing an embodiment of a method for manufacturing an ink jet head according to the present invention, and FIG. 2 is an enlarged sectional view showing an example of a wafer in a head cutting and cutting / separating step. In the figure, 1 is a heater wafer, 2 is a channel wafer, 3a and 3b are alignment marks, 4, 4a,
4b is a head chip, 5 is a photosensitive resin layer, 6 is an adhesive,
7a, 7b and 7c are cutting positions, 8 is a cleaning liquid, 11 is a heater, 12 is a pit, 13 is an ink reservoir, 14 is an ink flow path, and 15 is a bonding pad.

In the step shown in FIG. 1A, a heater wafer 1 is manufactured. The heater wafer 1 is made of a Si wafer, and as shown in FIG. 2, the heaters 11, the individual electrodes and the common electrodes (not shown), the bonding pads 15,
A not-shown protective layer and the like are formed by an LSI process. Further, in the step of FIG. 1B, after a photosensitive polyimide resin is spin-coated, a desired pattern is exposed and developed to form a photosensitive resin layer 5 and baking (Cure) is performed, whereby the heater wafer 1 is completed. . As the photosensitive polyimide resin, for example, Probim manufactured by Ciba-Geigy
ide (registered trademark), Pyral manufactured by Du-Pont
in PI 2722, etc. can be used. The photosensitive resin layer 5 is not formed on the heater 11 and the bonding pad 15 as shown in FIG. The concave portion on the heater 11 becomes a pit 12 for regulating the shape of a bubble generated by the heater 11. The alignment mark 3a is also formed on the heater wafer 1 during the above-described process.

In the step of FIG. 1C, the channel wafer 2
Is prepared. The channel wafer 2 is also made of a Si wafer, and as shown in FIG. 2, ink channels 14 and ink reservoirs 13 corresponding to heaters on the heater wafer 1 are formed by anisotropic etching. In addition, bonding pad 1
A concave portion is also formed in a portion corresponding to 5. Further, an alignment mark 3b is also formed. Thereby, the channel wafer 2 is completed.

Thereafter, in the step of FIG. 1D, for example, an adhesive 6 spin-coated on a PET film is thinly and uniformly applied to the adhesive surface side of the channel wafer 2 by transfer.

Next, in the step of FIG.
A heater wafer 1 manufactured in the steps (A) and (B);
The channel wafer 2 manufactured in the steps shown in FIGS. 1C and 1D is aligned and joined. Alignment is performed using alignment marks 3a and 3b that have been patterned in advance on the bonding surface side of each wafer, and is achieved with high accuracy by an alignment device while observing using, for example, an infrared microscope. The two wafers are baked (Cure) after alignment and bonding.

The step of FIG. 1F is a step of cutting and cutting and separating each head chip 4. In this step, a cutting step of cutting the channel wafer 2 at the cutting position 7a to expose the bonding pad 15 provided on the heater wafer 1 and a discharge port surface of the two wafers joined in FIG. And a dicing step of cutting at a cutting position 7b in order to define the flow path length, and a cutting step of cutting at a cutting position 7c and cutting and separating each head chip. In FIG. 2, the portion to be cut is indicated by a dashed line. Here, in the dicing step, cutting for forming a groove is performed, but cutting may be performed so as to also serve as a cutting step. In this step, the head chips 4 are cut and separated.

The step of FIG. 1G is a step of cleaning the head chips 4 cut and separated in the step of FIG. If chips, dust, and the like generated by the cutting in FIG. 1F remain in the head chip 4, ink ejection failure or the like is caused, and image quality is deteriorated. Therefore, in this step, the chips, dust and the like are washed away, and the head chip 4 is kept in a clean state.

FIG. 3 is an explanatory diagram of an example of the ink jet head. In the figure, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. 16 is a bonding pad, 17 is a discharge port, 18 is a fixing substrate, and 19 is a bonding wire. The head chip 4 manufactured by the process as shown in FIG. 1 is die-bonded on a fixing substrate 18, and a bonding pad 16 on a printed wiring board (not shown) on the fixing substrate 18 and a bonding pad 15 on the heater wafer 1. And bonding wire 1
9 make an electrical connection. Thereafter, connection of sealing, joints, and the like is performed as necessary, thereby completing the ink jet head.

FIG. 4 is a front view showing an example of cutting the discharge port in the dicing step. In the figure, 21 is a blade.
In the manufacturing process of the ink jet head shown in FIG. 1, the dicing process for forming the discharge port surface and defining the flow path length is conventionally formed in one process. However, in this embodiment, for example, as shown in FIG.
Divide and cut three times. The area B is a cutting area including the discharge port. The upper region of the region B is referred to as a region A, and the lower region of the region B is referred to as a region C.

The cutting of the region B requires high precision and high quality for forming the discharge port surface and determining the flow path length. Therefore, the feed speed v2 at the time of cutting the region B is cut at a speed for cutting the constituent material of the head with high quality. The feed speed v1 at the time of cutting the area A is, for example, the area B
Is set to be three times the feed speed v2 at the time of cutting.
The feed speed v3 when cutting the area C is the same as the feed speed v2 when cutting the area B. Since the feed speed v3 at the time of cutting in the region C does not have a discharge port, cutting can be performed at a higher feed speed. However, the blade fluctuates due to the high feed rate, and the
May affect the cutting surface. Therefore, area C
The feed speed v3 at the time of cutting of region B is changed to the feed speed v at the time of cutting of region B.
By cutting at a speed of 2 or less, it is possible to prevent the influence on the upper cut surface and improve the yield.

Specifically, the constituent material of the head is mainly Si
, The feed rate v2 for cutting the area B with high quality is, for example, 2.0 mm / sec.
And it is sufficient. Also, the feed speed v1 is three times that of 6.
It may be 0 mm / sec. The feed speed v3 may be set to 2.0 mm / sec, which is the same as the feed speed v2. Also,
Each cutting depth h1, h2, h3 of each subdivided cutting process
Are 350, 350, and 400 μm, respectively. The blade 21 used has a diamond ultra-fine diameter (grain size 3).
No. 000) is coated with a resin (resin) and has a diameter of 52 mm.
rpm.

Here, the rotation speed of the blade is P (rotation / s).
ec), the cutting blade radius is R (mm), and the cutting blade width is W (m).
m), the feed rate is V (mm / sec), and the cutting depth is H (mm), the cutting volume per unit area and unit time of the cutting blade U = V × H × W / (2 × π × R × P ×
W) (mm ³ · sec / mm ² · sec) is considered. In the specific example described above, the cutting volume U ₁ of the area A = 2.57 × 1
0 ^-5 , the cutting volume U ₂ in the region B = 8.58 × 10 ^-6 , and the cutting volume U _{3 in the} region C = 1.03 × 10 ^-5 .

In general, high-quality cutting conditions using a blade 21 such as a resin blade with high wear, for example, in the case of Si, a cutting volume U <1.0 × 10 ⁻⁵ (m
When cutting is continued at m ³ · sec / mm ² · sec), the cutting edge becomes uneven due to wear. FIG. 5 is an explanatory view of the tip cross-sectional shape of the blade. FIG. 5 (A) shows the initial blade tip cross-sectional shape.
(B) and FIG. 5 (C). The wear as shown in FIG. 5B is largely caused by the load and heat at the blade tip, and becomes more remarkable when the grinding depth is deep. When the tip of the blade has a sectional shape as shown in FIG. 5 (C), the force received by the blade from the workpiece is biased, and the blade is bent during cutting.

FIG. 6 is an explanatory diagram of the tip shape of the blade and the bending of the cut surface. As shown in FIG. 6A, in the initial cross-sectional shape of the blade, the force received from the workpiece is uniform, so that the blade can be cut straight. However, with the cross-sectional shape of the tip of the blade as shown in FIG. 6B, the blade is bent at the time of cutting, and cutting is performed obliquely. This blade bend is 50 μm
To the extent, this results in variations in the accuracy of the flow path length (TCL).

In general, in order to suppress the blade bending described above, the amount of blade protrusion from the flange (blade holding jig) may be reduced and the blade width may be increased. However, the blade protrusion amount cannot be smaller than the cutting depth. In the above-described specific example, since the general Si wafer is bonded to two wafers, it is difficult to reduce the blade protrusion amount to 1 mm or less. In addition, increasing the blade width increases the cutting width, and when cutting a large number of head chips from a wafer, the head removal height is reduced, leading to an increase in the cost of the head chips. Further, it is also possible to carry out a step of adjusting the shape of the blade (truing) every time a certain cutting is performed. However, in this method, several times of truing are required in one wafer, and alignment with a workpiece is required each time, so that productivity is significantly deteriorated.

FIG. 7 is an explanatory diagram of the change in the blade feed speed and the tip shape of the blade. As described with reference to FIG. 5, at the feed rate of the blade that achieves high cutting quality, wear as shown in FIG. 7A was shown. As shown in (B), the amount of wear increases, but the shape becomes uniform. This is because the excessive cutting resistance accelerates the loss of diamond particles and the wear of the resin portion. Even if the blade is once unevenly worn, the cutting by the high-speed feeding makes the unevenly worn protrusions even and allows a constant shape correction. At this time, new diamond particles and pockets (dents) are formed at the same time, and a sharpening effect is obtained. At this time, if the blade feed speed is higher than a certain value, the load on the blade becomes excessively large, causing a large run-out or breakage of the blade. This is greatly affected by the cutting depth and the like, but the limit is about 10 times under the same conditions.

By applying the selected feed rate in consideration of such characteristics, in the entire wafer cutting process,
Shorter cutting times, higher precision and higher quality have been achieved. That is, conventionally, when the discharge port surface was cut once, the cutting depth is deep, and therefore, in order to cut with high accuracy and high quality, the feed speed in the region B is about 1/3 of the feed speed. Need to cut. However, as in the above-described embodiment, since a part of the region having no discharge port is cut by high-speed feeding, the cutting time can be shortened as a whole, and the accuracy and quality of the region having the discharge port can be maintained. be able to.

FIG. 8 is a front view showing another example of cutting the discharge port in the dicing step. In this example, the upper region of the region B including the discharge port 17 is further divided into three. This 3
The divided upper regions A1, A2, A3 are cut, for example, at a feed rate of 20 mm / sec. By doing so, the entire cutting time is shortened, and the cutting is performed at a high speed with a small cutting depth, so that the correction of the blade shape is better and more stable than in the case shown in FIG. Here, for example, a blade diameter of 50 mm and a rotation speed of 4
Assuming that the rotation speed is 000 rpm and the cutting depth is 100 μm, the cutting volume per unit area and unit time of the cutting blade U ₁ = 1.9.
It is 1 × 10 ⁻⁵ (mm ³ · sec / mm ² · sec).

FIG. 9 is an enlarged sectional view showing an example of a dicing portion of a wafer. In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals. 31 is a heater protection film, and 32 is a common electrode. When the discharge surface is formed and the flow path length is determined by dicing, the shape of the channel wafer 2 may be different in the blade width direction at the cutting line as shown in FIG. Cutting a portion having such a shape promotes uneven wear of the blade. But,
When the cutting method as shown in FIG. 8 is used, the shape of the blade is corrected to a favorable state before cutting the region including the discharge port, so that even when cutting the region including the discharge port, the blade is stable. Can be processed in a regular manner. Therefore, an extra space, such as a longer flow path, is not required for cutting, which leads to an improvement in head height.

Further, in the example of FIG.
Was set to 450 and 350 μm, respectively. At this time, the cutting volume per unit area and unit time of the cutting blade in the region B and the region C is U ₂ = 8.60 × 10, respectively.
^-6 , U ₃ = 6.69 × 10 ^-6 (mm ³ · sec / mm ²
Sec). Thereby, the load on the blade in the cutting process of the region C is reduced, and the interference of the runout of the blade with the surface formed by the upper cutting is prevented.
Defects near the discharge port can be reduced. As a method of reducing the load on the blade in the cutting process in the region C from the upper portion, a method of changing the rotation speed or the feed speed of the blade is also possible, but a change / stabilization time is required to change the rotation speed. The method of changing the cutting depth or the feed speed as described above is preferable because the head manufacturing process time is lengthened.

As described above, the wear as shown in FIG. 5B is largely caused by the load and heat at the blade tip. Cutting by the cutting blade as described above is a process also called grinding, and heat is generated in the grinding region.
For this reason, grinding water (cooling water) is supplied to the grinding area to prevent wear due to heat. However, abrasion at the central portion in the blade width direction as shown in FIG. 5B is largely due to insufficient supply of grinding water.

FIG. 10 is an explanatory view of a conventional method of supplying grinding water. FIG. 10A is a schematic view of the method of supplying grinding water.
FIG. 10B is a cross-sectional view of a ground portion, and FIG. 10C is a plan view of the ground portion. In the figure, 21 is a blade, 22 is grinding water,
23 is a grinding water nozzle, 24 is an object to be ground, and 25 is a grinding groove. The feed direction of the blade 21 is from right to left in the figure. According to the conventional method of supplying the grinding water 22, FIG.
As shown in (A), the grinding water nozzle 23 and the blade 21
Line a connecting the center of the grinding water nozzle 23 and the blade 21
The grinding water 2 is applied to the blade 21 between the outer periphery of the
2 is supplied directly. This is to supply the grinding water 22 to the side surface of the blade 21 well. When a blade using an ultra-fine diamond as described above, that is, a blade having a small unevenness on the side surface and cutting is performed under the condition of small blade run-out, grinding water 22 is provided between the workpiece and the blade 21. There is not enough spacing to supply Therefore, in the method shown in FIG. 10 (A), sufficient grinding water 22 is not supplied to the grinding portion at the tip of the blade 21, and as described above, the blade width direction as shown in FIG. Wear was likely to occur at the center. This tendency becomes more remarkable as the depth of the grinding groove increases. Further, as shown in FIGS. 10B and 10C, in the conventional method of supplying the grinding water 22, since the grinding water 22 is directly applied to the blade 21, most of the grinding water 22 is on the workpiece 24. And was not sufficiently supplied to the ground portion. Although it is conceivable to improve the shortage of the grinding water 22 by increasing the flow rate, since the grinding water 22 is directly applied to the blade 21, an extra load is applied to the blade 21, causing the blade to oscillate. As a result, the grinding quality was reduced.

FIG. 11 is an explanatory view of an example of a method for supplying grinding water according to the present invention. FIG.
FIG. 11B is a sectional view of a ground portion, and FIG. 11C is a plan view of the ground portion. The reference numerals in the figure are the same as those in FIG. The feed direction of the blade 21 is from right to left in the figure, as in FIG. In the method of supplying the grinding water 22 according to the present invention, the grinding water 22 is not directly supplied to the blade 21,
Grinding water 22 is supplied to the grinding portion via a grinding groove 25 formed by grinding. By supplying such grinding water 22, the amount of the supplied grinding water 22 scattered on the surface of the workpiece 24 is reduced, and the grinding groove 2 is supplied.
The grinding water 22 is sent to the grinding portion along with the rotation of the blade 21 along 5. Therefore, the grinding water 22 can be sufficiently supplied to the grinding portion, and wear as shown in FIG. 5B does not easily occur, and good grinding quality can be obtained.

In the method of supplying the grinding water 22 according to the present invention, the grinding water
2, the supply angle θ of the grinding water 22 with respect to the bottom surface of the grinding groove 25 is desirably 0 ° to 45 °, more preferably 0 ° to 30 °. Good grinding quality can be obtained.

FIG. 12 is an explanatory diagram showing a comparison result of cutting time, flow path length accuracy, and yield between a head manufactured by the manufacturing method of the present invention and a conventional manufacturing method. As a conventional method of manufacturing a head, a method of forming a discharge port surface by one cutting and a conventional method of simply performing multi-stage (three-stage) cutting were used. At this time, the conventional grinding water supply method as shown in FIG. 10 was used. As a manufacturing method of the present invention, the case of cutting into three parts shown in FIG. 4 in “Example 1 of the present invention” is shown, and FIG. 8 is shown in “Example 2 of the present invention” and “Example 3 of the present invention”. 3 shows a method of cutting the uppermost stage further into three parts. "Example 2 of the present invention" and "Example 3 of the present invention" are different in a method of supplying grinding water. In "Example 1 of the present invention" and "Example 2 of the present invention", the method for supplying grinding water of the present invention as shown in FIG. 11 was used. The supply angle θ of the grinding water is 25 °. In "Example 3 of the present invention", a conventional grinding water supply method as shown in FIG. 10 was used. Here, in each case, the flow rate of the grinding water was set to 1.5
1 / min.

FIG. 12 shows the yield from the cutting time, the flow path length accuracy, and the quality of the discharge port when cutting is performed by each method. The flow path length accuracy of this evaluation result is 2
The alignment accuracy within about μm is included. FIG.
As can be seen with reference to FIG.
It is apparent that the accuracy of the flow path length and the yield have been greatly improved and the cutting time has been shortened as compared with the related art. That is, from the comparison between the “conventional one-stage example” and the “conventional multi-stage example” and the “inventive embodiment 3,” the use of the cutting method of the present invention significantly improved the flow path length accuracy and the cutting time. It has been shortened and the yield has been improved. From the comparison between "Example 2 of the present invention" and "Example 3 of the present invention", the yield can be greatly improved by changing the method of supplying the grinding water. As described above, even if only one of the cutting method and the method of supplying the grinding water is greatly improved as compared with the related art, as in “Example 1 of the present invention” and “Example 2 of the present invention”. By using both the cutting method of the present invention and the method of supplying grinding water, it is possible to perform better cutting.

FIG. 13 is a configuration diagram showing another head structure. FIG. 13A is a front view, and FIG. 13B is a cross-sectional view. In the figure, the same parts as those in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted. 41 is a photosensitive resin layer,
42 is a partition.

The heater wafer 1 is made of a Si substrate, and the heater 13, electrodes (not shown), signal circuits, etc.
Formed with technology. A photosensitive resin layer 5 using polyimide is provided thereon, and the pits 12, bonding pad portions (not shown) and the like are patterned. In this example, the channel wafer 2 functions as a top plate, and a photosensitive glass plate is used. The ink reservoir 13 is formed on the channel wafer 2, a photosensitive resin layer 41 is provided, and a photosensitive resin is patterned thereon to form a partition 42. Next, the heater wafer 1 and the channel wafer 2 are joined to form an ink flow path 14 and cut and separated to produce an ink jet head. The discharge port 17 appears on the cut surface.

FIG. 14 is a front view showing an example of cutting a discharge port in a dicing step in another head structure. In this example, the cut surface is divided into a region B including the photosensitive resin layer 5, a region thereabove and a region C therebelow. Further, the region above the region B is divided into two, and cutting is performed for each region as regions A1 and A2. The number of divisions of this area is not limited to this. In the head structure of this example, since photosensitive glass is used as the channel wafer 2, the cutting of the region B is performed under conditions suitable for the photosensitive glass. Area A1, A2
Is performed at a feed speed v1 higher than the feed speed v2 in the cutting of the region B. The cutting depth is made shallow by dividing the region, and the feed speed v1 of the regions A1 and A2 can be set to about 10 times the feed speed v2 of the region B. By cutting at such a feed rate, the blade can be dressed. Since the heater wafer 1 is made of a Si substrate, the cutting of the region C is performed at a feed speed suitable for cutting Si. As a result, it is possible to reduce the influence on the already cut surface due to the movement of the blade or the like.

More specifically, for example, the cutting depth of the regions A1 and A2 is 200 μm, the region B is 450 μm, the region C is 550 μm, and a 52 mm-diameter blade called a metal resin having a diamond grain size of 600 is used.
The cutting is performed under the conditions of a rotation speed of 40,000 rpm. At this time, the feed speed v1 at the time of cutting the areas A1 and A2 is set to 1.
0 mm / sec (U ₁ = 1.84 × 10 ⁻⁶ ), and the feed speed v2 at the time of cutting the area B is 0.1 mm / sec (U ₂ = 4.13 × 1) which is a condition suitable for the photosensitive glass.
0 ^-7 ), the region C is a feed speed v3 as a condition suitable for Si.
= 1.0 mm / sec (U ₃ = 5.05 × 10 ⁻⁶ ).

As shown in the above two examples, not only the object to be cut (Si, glass, etc.) but also the resin type of the blade to be used, the ultrafine diamond diameter and the cutting depth, the number of rotations of the blade, the cooling water ( Grinding water)
The feed rate for high quality cutting will be different. The feed rate suitable for the workpiece in the present invention is, when the above-mentioned various conditions are fixed, within a range of a feed rate that can be selected from the quality around the discharge port, the upper limit speed in consideration of a margin. pointing. The feed speed selected in this manner is such that the ultra-fine diamond diameter of the crushed (or rounded) blade surface is appropriately missing and a new ultra-fine diamond diameter (diamond grains with sharp edges) is exposed. High quality dicing quality can be obtained within a certain range.

In addition, the conditions for the correction / sharpening of the blade in the present invention are such that the shape of the blade is corrected by forcibly causing the loss of the diamond ultra-fine diameter, in contrast to the above-described condition of the appropriate diamond ultra-fine diameter loss. It is.
For example, in a resin blade, these are substantially determined by the material to be cut and the cutting volume per unit area / unit time U determined by the blade diameter, the number of revolutions, the feed speed and the cutting depth.

FIGS. 15 to 17 are explanatory views of the cutting volume per unit area and unit time, the quality of the discharge port, and the worn shape of the blade. FIGS. 15 and 16 show the case where the workpiece is Si. FIG. 17 shows a case where the workpiece is glass. These tables show the results of evaluating the quality of the discharge port and the change in blade shape when the cutting volume per unit area / time: U is changed. Here, the good discharge port quality means that the average discharge port has no chip or defect of 2 μm or less, and the deformation amount after a cutting length of 200 cm (d in FIG. ) Is 50 μm or less. For example, in the case of a 200 μm-thick blade, if the amount of deformation of the worn shape of the blade exceeds 50 μm, it is determined that the probability of the cross-sectional shape of the blade becoming the shape shown in FIG. I have.

When the object to be cut is Si, a blade having a diamond grain size of # 3000 and a blade width of 200 μm is used, the amount of protrusion from the flange, which is a blade holder, is 1.5 mm, and the grinding water efficiently hits the cut portion. An angle of, for example, a supply angle θ shown in FIG. 11B is set to an angle of 25 °, and an amount of 1.5 l / min is supplied. The diamond grain size of the blade greatly affects the quality of the discharge port. When the object to be cut is Si, a number of about 1000 to 5000 is selected in order to improve the quality of the discharge port. Here, the results shown in FIGS. 15 and 16 are equivalent to the above-described range of the diamond grain size even if the grain size is different, by sliding the required quality of the average chipping of the discharge port.

As shown in FIGS. 15 and 16, when the object to be cut is Si, the conditions for obtaining good discharge port quality are as follows:
1.4 × 10 ⁻⁵ (mm ³ · sec / mm ² · sec) or less, preferably U = 2 to 7 × 10 ⁻⁶ (mm ³ · s
ec / mm ² · sec) is good. The feed accuracy at which the wear shape of the blade is good is 0.9 × 10 ⁻⁵ (mm ³ · se
c / mm ² · sec), and preferably 1.5 to 3.
0 × 10 ⁻⁵ (mm ³ · sec / mm ² · sec) is good. In the table, × in the column of discharge port quality and blade wear shape
× indicates the occurrence of blade damage due to excessive cutting resistance.
X indicates that the blade shows good quality in the initial state due to crushing of the blade, but deteriorates with time.

From FIGS. 15 and 16, U = 0.9 to 1.8.
× 10 ^-5 (mm ³ · sec / mm ² · sec) and 4.3
^{~6.4 × 10 -5 (mm 3 ·} sec / mm 2 · sec)
In the vicinity area, the evaluation of the discharge port quality and the blade wear shape depending on the magnitude of U may be reversed. This is because there are many combinations of these values for one U value because the value of U depends on the rotation speed of the blade, the cutting depth, the feed speed, and the blade diameter. In the above-described region, the quality of the discharge port can be ensured depending on the combination, and the blade wear shape can be improved in another combination. Among these values, the feed speed and the cutting depth have a greater influence than other factors, and the feed speed particularly greatly affects the wear shape of the blade. Therefore, even if the value of U is the same, it is more effective to reduce the cutting depth and increase the feed speed to correct the blade shape.

Even when the object to be cut shown in FIG. 17 is a glass material, there is a slight difference, but the tendency is almost the same as when the object to be cut is Si, and the value of U is about 1/10. It has become. The blade used has a diamond grain size of 60
It is a No. 0 blade with a width of 300 μm, and other conditions such as the amount of protrusion from the flange and the cooling water are the same as those when the workpiece is Si. The evaluation shown in FIG. 17 is an evaluation when a grooved photosensitive glass is cut, and is different from an actual head shape. In addition, the quality of the discharge port is determined to be non-defective by determining that there is no chipping of 10 μm or more in the photosensitive glass groove of the sample. This is shown in FIG. 1 for an actual head.
This is because the head configuration as shown in FIG. 3 is assumed, and since there is no glass near the discharge port, the quality required from the discharge directionality becomes moderate.

From FIG. 17, the cutting of the area including the discharge port is
= 1.5 × 10 ^-6 (mm ³ · sec / mm ² · sec)
Hereinafter, the blade correction condition is U = 1.9 × 10 ⁻⁶ (mm ³
Sec / mm ² · sec) or more is selected.

Cutting volume per unit area / unit time: U
Does not ideally relate to the thickness of the blade. However, in practice, when the thickness of the blade becomes extremely large, the supply of cooling water to the cutting action portion becomes uneven, which causes cutting failure. If the thickness of the blade is extremely thin, the blade will run out and the quality will be degraded. Therefore, a blade having a width of about 0.05 to 1.0 mm is usually selected.

The present invention is not limited to the above-described example, and the direction in which the blade is fed can be freely selected.
In the case of a triangular discharge port shape as shown in FIGS. 4 and 8, in particular, in the cutting area B including the discharge port, the blade rotation direction is set from the bottom to the top with respect to the blade feed direction. In addition, defects due to chipping on the slope of the discharge port can be improved. In addition, the head structure is not limited to the above-described structure, and can be applied to ink jet heads having various structures. For example, a structure in which only the flow path length is defined by cutting and an orifice plate is separately attached may be used. Applicable.

In the above description, an example in which the cutting for correcting the shape of the blade is applied to a part of the multistage cutting at the discharge port surface is shown, but the present invention is not limited to this example. For example, the discharge port surface is formed by conventional one-stage cutting, and FIG.
The cutting 7a for exposing the wire bond portion shown in (1) may be cut under cutting conditions for correcting the shape of the blade, and after correcting the shape of the blade, the discharge port surface may be cut.

[0070]

As is apparent from the above description, according to the present invention, it is possible to stably produce a large number of heads with high precision and high quality without requiring an additional step or the like. In addition, there is an effect that the production time can be shortened.

[Brief description of the drawings]

FIG. 1 is a process chart showing one embodiment of a method for manufacturing an ink jet head of the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating an example of a wafer during a head cutting and cutting separation process.

FIG. 3 is an explanatory diagram of an example of an inkjet head.

FIG. 4 is a front view showing an example of cutting a discharge port in a dicing step.

FIG. 5 is an explanatory view of a tip cross-sectional shape of a blade.

FIG. 6 is an explanatory diagram of the tip shape of a blade and the bending of a cut surface.

FIG. 7 is an explanatory diagram of a change in blade feed speed and a tip shape of the blade.

FIG. 8 is a front view showing another example of cutting the discharge port in the dicing step.

FIG. 9 is an enlarged sectional view showing an example of a dicing portion of the wafer.

FIG. 10 is an explanatory view of a conventional method for supplying grinding water.

FIG. 11 is an explanatory diagram of an example of a method for supplying grinding water according to the present invention.

FIG. 12 is an explanatory diagram illustrating a comparison result of a cutting time, a flow path length accuracy, and a yield of a head manufactured by the manufacturing method of the present invention and a conventional manufacturing method.

FIG. 13 is a configuration diagram showing another head structure.

FIG. 14 is a front view showing an example of cutting an ejection port in a dicing step in another head structure.

FIG. 15 shows a unit area when the object to be cut is Si.
It is explanatory drawing of the cutting volume per unit time, the quality of a discharge port, and the wear shape of a blade.

FIG. 16 shows a unit area when the object to be cut is Si.
It is explanatory drawing of the cutting volume per unit time, the quality of a discharge port, and the wear shape of a blade.

FIG. 17 is an explanatory diagram of a cutting volume per unit area and unit time, a quality of a discharge port, and a worn shape of a blade when a workpiece is glass.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heater wafer, 2 ... Channel wafer, 3a, 3b ...
Alignment marks, 4, 4a, 4b ... head chips,
5 photosensitive resin layer, 6 adhesive, 7a, 7b, 7c cutting position, 8 cleaning liquid, 11 heater, 12 pit, 1
3: ink reservoir, 14: ink flow path, 15, 16: bonding pad, 17: discharge port, 18: fixing substrate, 1
9: Bonding wire, 21: Blade, 22: Grinding water, 23: Grinding water nozzle, 24: Grinding object, 25: Grinding groove, 31: Heater protective film, 32: Common electrode, 41: Photosensitive resin layer, 42 ... partition walls.

Claims (13)

(57) [Claims] 1. An ink jet head having an ink flow path and a discharge port for ejecting ink droplets connected to the ink flow path, wherein the discharge port and / or its peripheral surface are formed by a cutting process using a rotary cutting blade. And / or a method for defining the length of the ink flow path, wherein the cutting step is divided into multiple stages in the thickness direction of the workpiece, and the region including the discharge port is B, and the region not including the discharge port. If the upper region of B is A and the relative feed speed of the rotary cutting blade to the workpiece in each region is V _B , _VA ,
The method for manufacturing a ink jet head, characterized in that the V _A> V _B. 2. The method according to claim 1, wherein V _A ≧
A method for manufacturing an ink jet head, wherein the method is 3 × V _B. 3. A method for manufacturing an ink jet head according to claim 1, wherein the region A is further divided and cut in multiple stages. 4. A method for cutting while rotating a resin-based cutting blade made of resin with diamond particles in an ink jet head having an ink flow path and an ejection port for ejecting ink droplets connected to the ink flow path. Rotation speed: P (rotation / sec), cutting blade radius: R (mm), cutting blade width: W (mm), feed speed: V (mm / sec),
When the depth of cut: H (mm), the cutting volume per unit area and unit time of the cutting blade: U = V × H × W / (2
× π × R × P × W) is 0.9 × 10 ⁻⁵ (mm ³ · sec)
/ Mm ² · sec) or more, comprising at least one or more cutting steps mainly for cutting silicon under the condition. 5. An ink jet head having an ink flow path and an ejection port for ejecting ink droplets connected to the ink flow path, wherein the cutting is performed while rotating a resin-based cutting blade in which diamond particles are solidified with a resin. The cutting conditions for the area mainly composed of silicon including the discharge port are determined by changing the cutting volume per unit area and unit time of the cutting blade: U to 1.4 × 10 ^−5.
(Mm ³ · sec / mm ² · sec). 6. In the invention according to claim 1, when the object to be cut is mainly made of a silicon material, the region B is cut under the conditions shown in claim 5, and the region A is shown in claim 4. A method for producing an ink jet head, characterized in that cutting is performed under the following conditions. 7. In an ink jet head having an ink flow path and an ejection port for ejecting ink droplets connected to the ink flow path, a method of cutting while rotating a resin-based cutting blade in which diamond particles are solidified with resin, Cutting volume per unit area and unit time of cutting blade: U is 1.9 × 10
^-6 (mm ³ · sec / mm ² · sec) or more A method for producing an ink jet head, comprising at least one or more cutting steps mainly for cutting glass under conditions. 8. An ink jet head having an ink flow path and a discharge port for ejecting ink droplets connected to the ink flow path, wherein the cutting is performed while rotating a resin-based cutting blade in which diamond particles are solidified with resin. The cutting conditions for the area mainly composed of a glass material including the discharge port are determined by changing the cutting volume per unit area and unit time of the cutting blade: U to 1.5 × 10
^A method for manufacturing an ink jet head, wherein cutting is performed under a condition of less than ^-6 (mm ³ · sec / mm ² · sec). 9. In the invention according to claim 1, when the object to be cut is mainly made of a glass material, the area B is cut under the conditions shown in claim 8, and the area A is shown in claim 7. A method for producing an ink jet head, characterized in that cutting is performed under the following conditions. 10. In the invention according to claim 1, 6 or 9, when the workpiece is divided into three or more steps in the thickness direction, the cutting volume per unit area and unit time of the cutting blade in the cutting process: Assuming that U is a region including the discharge port B, an upper region of the region B not including the discharge port is A, and a lower region C of the region B not including the discharge port, U _C
≦ U _B <manufacturing method of an ink jet head and setting the U _A. 11. A method of manufacturing an ink jet head for grinding an ink jet head having an ink flow path and an ejection port for ejecting an ink droplet connected to the ink flow path while rotating a rotary cutting blade, wherein the rotary cutting blade is Wherein the grinding water is supplied directly to a grinding area of the rotary cutting blade via a grinding groove formed by the rotary cutting blade without directly contacting the grinding water. Method of manufacturing. 12. The method according to claim 11, wherein a supply angle of the grinding water is 0 to 45 ° with respect to a feed direction of the rotary cutting blade. 13. The method as claimed in claim 1, wherein the first or sixth or the ninth or tenth aspect of the present invention is performed.
In the invention described in the above, when performing a grinding step divided in the thickness direction of the workpiece, the region including the discharge port is B,
12. A grinding process for at least the region B and the region C, where A is an upper region of the region B not including the discharge port and C is a lower region of the region B not including the discharge port. Or a grinding method under the supply condition of the grinding water described in 12 above.