JPH04158044A - Manufacture of print head for ink jey printer - Google Patents

Abstract

PURPOSE:To prevent ink from pushed out to an adjacent channel and jetted through an adjacent nozzle by polishing the junction fades of first and second plates of a photosensitive glass so that a specific center line average roughness is achieved and then stacking the first and second plates and fusing them thermally. CONSTITUTION:A photosensitive glass is cut out into first and second hexagonal plates. An ink sump groove 3, a jet groove 4, a flow-out channel 5 and an ink supply through-hole 6 are formed in the first plate 1 whereas an ink sump through-hole 7 and an ink supply channel 8 are formed in the second plate 2. Average center line roughness (Ra) on one junction face of these plates is set 0.04mum or less and that on the other opposing junction face is set in the range of 0.3-5.0mum. These plates are then stacked and thermally fused leaving no unfused part between the junction faces.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves stacking two or three photosensitive glass plates in which grooves, holes, etc. are formed in a predetermined pattern, and then heat-sealing them. The present invention relates to a method of manufacturing a print head for an inkjet printer in which ink reservoir grooves, ink projection grooves, etc. are formed.

[Conventional technology]

As shown in Figures 1 and 2, the print head for an inkjet printer has ink reservoir grooves, ink projection grooves, etc. formed inside by stacking and heat-sealing two photosensitive glass plates. ing. Then, a piezoelectric element is provided on the top surface of the plate facing each projection groove,
The volume of the projection groove is forcibly reduced by bending it toward the projection groove,
It is used by ejecting ink inside a projection groove from a nozzle.

A method for manufacturing a print head for an inkjet printer is described in Japanese Utility Model Application Publication No. 1552/1983. The manufacturing method is as follows.

A predetermined pattern is exposed to ultraviolet light on a photosensitive glass plate, and this is thermally developed to crystallize the exposed area. The photosensitive glass plate of this development method is then immersed in a hydrofluoric acid solution and the crystallized portions are etched to a predetermined depth to form grooves and through holes. After this etching process, both joint surfaces of the two plates are polished with high precision. Thereafter, the two plates are stacked with their joining surfaces aligned, held at high temperature for several hours, and joined by thermal fusion. In this way, a print head for an ink shed printer with an internal ink reservoir groove and an ink projection groove communicating with the groove is formed. ! Build.

[Problem to be solved by the invention]

However, when these two highly precisely polished plates are stacked and heat-sealed with their joint surfaces aligned,
An unfused portion may remain between the joint surfaces. The reason for this is that slight warping may occur during polishing of the plate.

In other words, when these slightly warped plates are stacked and heat-sealed, since both of the bonding surfaces are smooth, the surrounding contacting portions are first completely fused, and air is taken into the interior. Then, the air that is taken in may remain as an unfused portion because there is no place to escape.

In the print head for an inkjet printer obtained in this way, when the volume of the projection groove is contracted using a piezoelectric element, the ink pushed out from the projection groove passes through the above-mentioned unfused portion and flows into the adjacent area. It may be pushed out into the projection groove and sprayed from the adjacent nozzle as well.

The object of the present invention is to rapidly reduce the volume of the projection groove by acting on a piezoelectric element, so that ink pushed out from the projection groove passes through the unfused portion, is pushed out to the adjacent projection groove, and is ejected from the nozzle. It is an object of the present invention to provide a method for manufacturing a print head for an inkjet printer that prevents such problems from occurring.

[Means for Solving the Problem] In order to achieve the above object, the method for manufacturing a print head for an inkjet printer of the present invention includes preparing two or three photosensitive glass plates, and at least one of them. When forming desired grooves and/or through holes in one plate, stacking these plates, and joining them by heat fusion, one of the two or three photosensitive glass plates on each joining surface. The centerline average roughness of the joint surface (
Ra) is 0.04 μm or less, and the center line average roughness (Ra) of the other joint surface facing this is 0°3 μm to 5.0
It is characterized by stacking these plates and heat-sealing them after forming them into micrometers.

Next, the reason why the centerline average roughness (Ra) of the joint surface is limited as described above will be described.

Center line average roughness (Ra) of one joint surface is 0°3 μm ~
Even if it is 5.0 μm, if the center line average roughness (Ra) of the other bonded surface exceeds 0.04 μm, when the bonded surfaces are stacked together, both bonded surfaces are rough. The adhesion between the plates is poor, and when they are heat-sealed, an unfused portion may remain between their joint surfaces. Therefore, the center line average roughness (Ra) of one joint surface is 0.0
It is limited to 4 μm or less.

Furthermore, the center line average roughness (Ra) of one joint surface is 0.
Even if the center line average roughness (Ra) of the other joint surface exceeds 5.0 μm, the other joint surface will be too rough, and when stacked together with their joint surfaces together, the plates will not meet each other. Adhesion is poor. In addition, if the center line average roughness (Ra) of the other bonding surface becomes finer than 0.3 μm, the unevenness on both bonding surfaces becomes too fine (too much). , first, the surrounding contacting parts are completely fused, and air is taken inside.In this way, in either case, unfused parts may remain.Therefore, the The centerline average roughness (Ra) is limited to 0.3 μm to 5.0 μm.

In order to achieve a good production yield, a particularly preferable centerline average roughness (Ra) of the bonded surfaces is such that the centerline average roughness (Ra) of one bonded surface is 0.02 μm or less, and the centerline average roughness (Ra) of the other bonded surface is 0.02 μm or less. The center line average roughness (Ra) of is 0.5 μm to 2.0 μm.

The center line average roughness (Ra) was measured using a roughness meter (Surtronic type 3, manufactured by Taylor Hobson) and record #+ (
Mini lighter WTR771R type Nigella Fick M)
The measurement is carried out according to the Japanese Industrial Standards (JTS).
B 0601-1982).

[Operation Arrow] According to the above manufacturing method, even if air is taken into the joint surface by the warpage of the plate during heat fusion, there will be no unevenness of 0.3 μm to 5.0 μm on one of the joint surfaces. Because there is
Air can escape through the gap.

〔Example〕

Hereinafter, the method for manufacturing a print head for an inkjet printer according to the present invention will be described in more detail using Examples with reference to the drawings. However, the present invention is not limited to these examples.

FIG. 1 is an exploded view of the main parts of a print head for an inkjet printer. 1 is a first plate, and 2 is a second plate disposed opposite to the first plate l.

The first plate 1 and the second plate 2 have S as a main component.
in, ,Li,O,20. and A.I.

O8, other components include Nas O, ZnO, Sb*O1
Furthermore, the photosensitive glass was formed from photosensitive glass containing predetermined amounts of CeOa, Ag, and Au as trace components.

This photosensitive glass was cut out to obtain a first plate 1 and a second plate 2 each having a hexagonal planar shape as shown in FIG. At this time, the thickness of the first plate I was set to 1.5 mm, and the thickness of the second plate I was set to 1.5 mm.
The thickness of plate 2 was set to 0.51.

This first plate l has an ink reservoir groove 3 and a projection groove 4 (
4-1.4-2.4-3 and 4-4 respectively), outflow passage groove 5 (5-1.5-2.5-3 and 5-4 respectively)
, and a through hole 6 for ink supply. Next, an ink reservoir through hole 7 and an ink supply groove 8 were formed in the second plate 2. Note that the ink reservoir groove 3 and the ink supply through hole 6 of the first plate l are the ink reservoir through hole 7 and the ink supply groove 8 of the second plate 2, respectively.
is facing.

The ink reservoir groove 3, the projection groove 4, the outflow passage groove 5, the ink supply groove 8, and the through holes 6 and 7 were formed as follows.

First, in the tJ1 stage, a mask made of a chromium film with a predetermined pattern formed thereon is closely attached to the first plate 1 and the second plate 2, respectively, and ultraviolet rays are applied from above the mask for 10 seconds using a 600W mercury-xenon lamp. By irradiating, parts corresponding to the ink reservoir groove 3, the projection groove 4, the outflow passage groove 5, the ink supply groove 8, and the through holes 6 and 7 are exposed, and the exposed parts are exposed to the photosensitive metal. , nuclei consisting of Au particles were generated to form a latent image.

Next, as a second step, the first plate 1 and the second plate 2 after the latent image formation are heat-treated at 580°C for 1 hour, and the photosensitive metals Ag and Au in the exposed area (latent image) are used as nuclei to be exposed to acid. Easy crystals of lithium disilicate were precipitated.

Furthermore, as a third step, the first plate I and the second plate 2 after crystal precipitation are treated with a dilute hydrofluoric acid solution to form ink reservoir grooves 3, projection grooves 4, outflow passage grooves 5, and ink supply grooves 8. , and through holes 6 and 7 were formed. The ink reservoir groove 3, the projection groove 4, the outflow passage groove 5, and the ink supply groove 8 are formed on the first plate l and the second plate 2.
, joint surfaces 1a facing each other
The crystal portions described above from 2a and 2a were half-etched to a depth of 50 μm using a dilute hydrofluoric acid solution. Further, the through holes 6 and 7 were formed by etching the crystal portions until they penetrated the front and back sides.

Next, the joint surface 1 of the first plate 1 formed in this way
After polishing the bonding surfaces 2a of the first plate I and the second plate 2 to a predetermined centerline average roughness (Ra), the first plate I and the second plate 2 are stacked and thermally fused.

As shown in Table 1, this heat fusion was carried out on eight sets of samples with different center line average roughnesses (Ra) of the joint surface 1a of the first plate 1 and the joint surface 2a of the second plate 2. . However, 翫l and NαG in the table are examples of the present invention, and &7 and Na3 are comparative examples. The unit of each is μm.

(Margin below) Table 1 First plate 1 and second plate 2 made of the above eight sets of samples are stacked together with their joint surfaces aligned, 850
The mixture was held at .degree. C. for 2 hours and thermally fused to obtain a print head for an inkjet printer as shown in FIG.

In this way, the nozzles 9 (9-1, 9-2.9, respectively)
-3 and 9-4), and a projection groove 4 are formed inside.

Thereafter, a flexible thin film 10 is provided on the upper surface of the plate 2 to close the ink reservoir through hole 7. This flexibility 41110
At the top, there is provided an IN node means (not shown) for controlling the amount of ink supplied to the ink reservoir groove 3, which is composed of a strain gauge, a sensor, a piezoelectric element, and the like. Furthermore, a piezoelectric element 11 (respectively 11-1, 11-2.11-
3 and 1l-4) are arranged (see Fig. 3).

Using the thus obtained inkjet printer print heads of samples &l and 8, for example, one of the four piezoelectric elements 11, 11-1, has a projection groove 4.
-1 and sends a pulse to replenish ink to the projection groove 4.
-1 was bent toward the projection groove 4-1, and the ink in the projection groove 4-1 was jetted to the outside through the nozzle 9-1.

As a result, in the print heads for inkjet printers according to samples Nα1 to Nc 6, the ink pushed out from the projection groove 4-1 is prevented from remaining unfused between the bonding surface 1a and the bonding surface 2a. , there was no ejection from the adjacent nozzle 9-2.

On the other hand, in the print heads for inkjet printers according to samples Nα7 and Nα8, an unfused portion remains between the bonding surface 1a and the bonding surface 2a, and the ink pushed out from the projection groove 4-1 is absorbed by the unfused portion. It was pushed out to the adjacent projection groove 4-2 through the part, and was ejected from the nozzle 9-2.

In the above embodiment, a method of manufacturing a print head for an inkjet printer is described in which two sheets of photosensitive glass are stacked, but it is also possible to stack three plates of photosensitive glass.

For example, FIG. 4 shows a print head for an inkjet printer formed by stacking three photosensitive glass plates having the same external shape as those of the previous embodiment.
- It is a sectional view in the same position as the A line. plate 12
This is a plate formed by penetrating the projection grooves 4 of the first plate l of the above embodiment from both front and back sides. The plate 13 is the same as the second plate 2 of the previous embodiment. Further, the plate 14 has no through holes or grooves, and has flat upper and lower surfaces.

In this case, the centerline average roughness (Ra) of the bonding surface 13a of the plate 13 is 0.01 μm, and the centerline average roughness (Ra) of the bonding surface 12a of the plate 12 facing this is 1.01 μm.
It was set to 0 μm. Furthermore, the centerline average roughness (Ra) of the joint surface 14b of the plate 14 is set to 0.01 μm, and the centerline average roughness (R
a) was set to 1.0 μm. Thereafter, they were joined by heat fusion.

Using the print head for an inkjet printer obtained in this way, the piezoelectric element was activated and the ink in the projection groove was ejected from the nozzle to the outside in the same manner as in the previous example. The ink ejected from the nozzle and pushed out from the projection groove was not ejected from the adjacent nozzle.

In addition, in each joint surface, the joint surface 13 is opposite to this embodiment.
a, 14b is the center line average roughness (Ra) I.

0 μm, and the center line average roughness (Ra
) Even when the thickness was set to 0.01 μm, the same effect as in this example was obtained.

〔Effect of the invention〕

As described above, according to the method of manufacturing a print head for an inkjet printer of the present invention, the center line average roughness (Ra) of one of the bonded surfaces of two or three photosensitive glass plates is 0.04 μm. The centerline average roughness (Ra) of the joint surface of the other plate facing this is 0.
．． After setting the thickness to 3 μm to 5.0 μm, these plates are stacked and thermally fused, so that no unfused portion remains between the joint surfaces of the plates. Therefore, when the piezoelectric element is activated to rapidly reduce the volume of the projection groove, the ink pushed out from the projection groove is prevented from being pushed out into the adjacent projection groove and ejected from the adjacent nozzle. There is.

[Brief explanation of drawings]

Fig. 1 is an exploded view of a print head for an inkjet printer, Fig. 2 is a perspective view of the print head for an inkjet printer, Fig. 3 is a sectional view taken along line A-A in Fig. 2, and Fig. 4 is another embodiment. FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2, showing the same position. 1... First plate 1a... Joint surface of first plate 2... Second plate 2a... Joint surface of second plate 3... Ink reservoir groove 4... Projection groove 5... Outflow Passage groove 6.7, through hole 8, ink supply groove 9, nozzle IO, replaceable thin film 11, piezoelectric element 12, 13, 14, plate

Claims (1)

[Claims] (1) Prepare two or three photosensitive glass plates, form a desired groove and/or through hole in at least one of them, stack these plates, and heat-fuse them. When bonding, the centerline average roughness (Ra) of one bonding surface of each bonding surface of the two or three photosensitive glass plates shall be 0.04 μm or less, and the centerline average roughness (Ra) of the other bonding surface facing this shall be Center line average roughness (Ra
) to 0.3 μm to 5.0 μm, and then stacking these plates and heat-sealing them.