JPH04161341A - Manufacture of ink jet recording head - Google Patents

Abstract

PURPOSE:To prevent improper contact between base plates by a method wherein a thermoplastic resin layer is formed on a first base plate in an ink passage like configuration and then prebaked, the same thin resin layer is formed on a second base plate, such resin layers are first joined together without baking and thermal curing and then baked and thermally cured. CONSTITUTION:A plurality of heat resistance arrays 4 and wiring electrodes 5 are provided on a first silicon base plate 1, spin coated with a photo-sensitive polyimide resin as a protective layer 2 and, after prebaking, subjected patterning exposure. A second silicon base plate 6 is provided with grooves 7 and an ink reservoir 8 formed corresponding to the first base plate and an adhesive layer 9 formed at its surface of joining with the resin layer 2 on the first base plate 1. When both the base plates are joined together without matching in positions, baking and thermal curing, since such a joining is effected before the end parts of the pattern are raised, there is no gap occurring between these base plates. When the thermal curing thereafter takes place, the raising is suppressed and the base plates will not be separated from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing an inkjet recording head,
In particular, it relates to a device in which two substrates are bonded together and a thermosetting resin layer between these two substrates is formed as an ink flow path.

(Prior Art) Conventionally, the method of manufacturing an inkjet recording head is as follows:
JP-A-61-230954, JP-A-62-336
As shown in Publication No. 48 and Japanese Patent Laid-open Publication No. 63-34152, a first substrate on which heating elements, wiring electrodes, and thick film insulation layers of a plurality of heads are formed, and the same number of substrates as the first substrate, There is a method in which the heads are aligned and bonded to a second substrate on which an ink flow path is formed, and then the heads are cut and separated into individual heads.

However, as shown in FIG. 6, the thermosetting resin pattern 2 of the thick film insulation layer swells at the end due to thermal contraction during curing.
2 occurred, and a gap was created between the two substrates, making it difficult to achieve uniform adhesion.

For example, when photosensitive polyimide resin is used as a thermosetting resin, the imidization rate reaches almost 100% by thermosetting at 400°C, but in order to reduce deformation and swelling during thermosetting, it is When thermally cured, the imidization rate remains at about 85%, and there are problems with insulation, thermal stability, and chemical stability.

Furthermore, if a large amount of adhesive is used on the thermosetting resin layer to prevent poor adhesion, the adhesive will bulge out when two substrates are bonded together, as shown in FIG.
The amount of ink droplets ejected changes as the ink droplets wrap around the ink droplets.

(Problems to be Solved by the Invention) The present invention solves the problem of poor adhesion due to swelling at the edges of the thermosetting resin layer pattern in a device in which the thermosetting resin layer between these two substrates is formed as an ink flow path. We propose a new manufacturing method for this purpose.

(Means for Solving the Problems) The present invention provides a method for manufacturing an inkjet recording head in which an ink channel is formed using a thermosetting resin, in which a thermosetting resin layer is formed in the shape of an ink channel on a first substrate. a first step of pre-baking after the first step; a second step of forming a thin layer of thermosetting resin on the second substrate; a third step of bonding the thermosetting resin layers so as to face each other without firing and thermosetting the second substrate; and after the third step, bonding the first substrate and the second substrate. A method for manufacturing an inkjet recording head, comprising a fourth step of firing and thermosetting a thermosetting resin. After forming a thermosetting resin layer pattern on the substrate, the substrates are bonded together before thermosetting.
After that, it is thermally cured.

(Function) According to the present invention, since the substrates are bonded to each other before thermal curing that causes swelling at the end of the pattern, no gap is created even when the substrates are bonded to each other.

Furthermore, since the pattern ends are in direct contact with the bonded substrates without any gaps, swelling is suppressed even when the pattern is cured by heat, and the substrates do not separate from each other.

The present invention will be explained below with reference to Examples.

(Example 1) A silicon substrate 1, which is a first substrate shown in FIG. There is. Protective layer photosensitive polyimide resin (e.g. CHIBA-GEIGY
5electilux HTR-3-200) is spin-coded onto a substrate 1 provided with a heating resistor and wiring electrodes, and after prebaking at 100'C for 20 minutes, an opening 3 corresponding to the heating resistor part and the outside of the chip are coated. In order to remove the wiring part, patterning exposure and development are performed.

At this stage, there is no swelling around the pattern that can be seen after heat curing, but as shown in FIGS. A groove portion 7 and an ink reservoir portion 8 are formed corresponding to the substrate 1, and the groove portion 7 and the ink reservoir portion 8 are connected by groove machining with a dicing saw or the like along the broken line in the figure to form an ink flow path. It is. Then the first silicon substrate l
The adhesive layer 9 shown in FIG. 2C is formed on the surface to be bonded to the upper resin layer.

The adhesive layer 9 is formed by first applying a resin layer (polyimide resin, e.g. 8electilux HTR-3-100 manufactured by CHIBA-GEIGY) as an adhesive layer on a flat substrate or film using a spin cord or the like. It is applied and transferred to the second silicon substrate 6 by the method described in (a). Therefore, according to this method, the resin does not enter non-contact parts such as the groove 7, and a thin adhesive layer of about 111 m can be formed.

After forming resin layers on the first and second substrates by the above method, they are aligned and bonded as shown in FIG. 3a.

At this time, as described above, the resin film layer formed on the first substrate has not yet been thermally cured, and therefore does not bulge due to contraction and deformation. Therefore, if pressure is applied to the two substrates in this state, they can be closely bonded without any gaps.

After further temporary fixing, the adhesive was finally heat cured at 400°C for 1 hour and completely bonded at the same time.

The bonded substrate is cut and separated into chips that will become individual heads using a dicing saw, as shown in FIG. 3, and furthermore, an ink supply port is attached and electrical connections are made to form a printable head.

(Example 2) Figures 4a and 4 show another example using the present invention.

A first silicon substrate l on which a heating resistor, electrodes, etc. are formed.
On top, a photosensitive polyimide resin layer (for example, 5electilux manufactured by CHIBA-GEIGY) was applied in the same manner as in Example 1.
HTR-3-200) was spin-coded and 100°Cl
Pre-bake for 20 minutes. Furthermore, patterning exposure,
The ink channel wall 9 is formed by the development process.

On the other hand, only the ink reservoir portion is formed on the second silicon substrate by anisotropic etching.

A photosensitive polyimide resin layer (for example, CHIBA-G
5electilux HTR-3-10 manufactured by EIGY
0) is directly spin-coded or spin-coded onto a film or the like, and then transferred onto a second silicon substrate.

Next, the first and second substrates are aligned and bonded together as shown in FIG. 4a. In this embodiment, since the ink channel wall is formed on the first substrate, alignment is easier than in (Embodiment 1).

Thereafter, it was heat cured at 400° C. for 1 hour to completely adhere.

The bonded substrate is divided into individual heads using a dicing saw, as shown in FIG. 4, and an ink supply port is attached and electrical connections are made to form a printable head.

(Example 3) FIG. 5 shows another embodiment using the present invention.

A first silicon substrate 1 on which a heating resistor, electrodes, etc. are formed.
On top, a photosensitive polyimide resin layer (for example, 8electilux manufactured by CHIBA-GEIGY) was applied in the same manner as in Example 1.
HTR-3-200) was spin-coded and 100°Cl
Pre-bake for 20 minutes. Furthermore, patterning exposure and development processes are performed to remove the heating resistor and the electrical connection between the chip and the outside. In this example, once 4
Heat curing is performed at 00°C for 11 hours.

Next, in the same manner as in Example 2, a polyimide resin layer is applied again, prebaked for 100 DEG Cl2O minutes, and patterned by exposure and development to form an ink channel wall. After that, it is bonded to a second silicon substrate and heated at 400°C.
Heat cure for 1 hour.

According to this embodiment, since all the walls of the ink flow path are made of the same material, it also has the advantage that instability in directionality due to differences in wettability etc. during ink ejection can be eliminated.

In each of the examples, photosensitive polyimide was used as the resin layer formed on the first substrate 1, but when polyimide resin is used, it can be thermally cured at high temperatures, so the imidization rate can be increased, and the It became possible to create a stable ink flow path. Moreover, it is not limited to this as long as it can be patterned. For example, even non-photosensitive polyimide can be patterned using a resist, or a dry film resist such as Liston (registered trademark) may be laminated and then patterned by exposure and development.

Furthermore, the resin on the second substrate can be similarly used as long as it can be thermally cured and bonded at the same time.

Further, if necessary, adhesion may be improved by applying an adhesion auxiliary agent such as an aminosilane adhesion promoter onto the substrate before forming the resin layer.

Furthermore, the method of the present invention can be applied to other inkjet methods (for example, those using piezo elements) in the process of bonding two substrates together.

(Effects of the Invention) As described above, according to the present invention, the number of parts with poor adhesion due to lifting of the substrates, etc. that occurs when two substrates are bonded is extremely reduced, and the yield is improved.

[Brief explanation of the drawing]

Fig. 1 shows a first substrate on which a heating element is formed, Fig. 2 shows a second substrate having a groove for forming a nozzle part and an ink reservoir, and Fig. 3.4.5 shows an embodiment of the present invention. Figure 6 shows the state of bonding two substrates together and the heads separated by cutting. Figure 6 shows the unevenness seen when heat-cured using the conventional technique. Figure 7 shows the state of the nozzle due to too much adhesive due to the conventional technique. It looks like the adhesive has gotten into it. 1.6 substrates, 2 thick film thermosetting resins, 4 heating elements, 5 electrodes 7
Groove, 8 Ink reservoir part, 9 Thin film thermosetting resin, 1
0 ink channel wall applicant Fuji Xerox Co., Ltd.

Claims (1)

[Claims] In a method for manufacturing an inkjet recording head in which an ink channel is formed using a thermosetting resin, a first step is performed in which a thermosetting resin layer is formed in the shape of an ink channel on a first substrate and then prebaked. a second step of forming a thin layer of thermosetting resin on a second substrate; and firing the first and second substrates that have undergone the first and second steps. a third step of joining the thermosetting resin layers so as to face each other without thermal curing; and after the third step, baking the thermosetting resins on the first substrate and the second substrate. and a fourth step of thermally curing the inkjet recording head.