JPS62176856A - Recording head - Google Patents

Abstract

PURPOSE:To prevent the deterioration in printing grade caused by the abrasion of the leading end part of a head due to printing, by forming a film, wherein high hardness fine particles are uniformly dispersed in an Ni-P alloy, on an insulating substrate material to use the same as an electrode. CONSTITUTION:A composite plating layer, wherein a fine particulate powder of tungsten carbide are uniformly coprecipitated and dispersed in a plating film by growing electroless nickel plating while the fine particulate powder of tungsten carbide is stirred in an electroless nickel plating bath containing a phosphorus component, is formed on an alumina ceramics substrate 8 and photoetching or laser processing is applied to said plating layer to remove unnecessary parts to form a plurality of electrode patterns which are, in turn, heat-treated, for example, at 250-550 deg.C for 20min-1.5hr. Thus formed electrode is excellent in abrasion resistance because of its extremely high hardness, for example, H1=1,000-1,400.

Description

[Detailed Description of the Invention] Technical Field> The present invention is particularly concerned with contacting an electrode with a resistive layer of a film formed by layering a resistive layer, a conductive layer, and an ink layer, and applying electricity to remove ink from the ink layer of the film. An electrode is brought into contact with the recording head of a printer using an electric transfer recording method that transfers onto plain paper, or the resistive layer of a film formed by layering a resistive layer and a conductive layer,
The present invention relates to a recording head that is suitable for use as a recording head for a thermal recording type printer or a discharge recording type printer that colors thermal paper that is brought into close contact with the conductive layer of the film by applying electricity.

<Prior Art> In recent years, in dot matrix printing devices, it has become necessary to arrange the recording needles of the recording head at a higher density due to the demand for improved printing quality. Specifically, it is said that 8 to 10 trees per mainland are required.

For this purpose, a recording electrode is brought into contact with the resistance layer of the current transfer film, which is formed by layering a resistance layer, a conductive layer, an ink layer, etc., and the resistance layer is made to generate heat by applying current to the recording electrode. Even in electrical transfer recording apparatuses that perform recording by melting ink and transferring it to recording paper, miniaturization of the recording needles has become an issue as the recording needles are arranged in a higher density. However, when miniaturizing the recording stylus, there are many problems that need to be solved, such as microfabrication technology, strength of the recording stylus holding structure 1, and life span.

There is already a device that has achieved high density recording heads in the above-mentioned current transfer recording devices, in which a tungsten foil layer is pasted with an adhesive onto a flexible polyimide substrate, and then etched to form recording electrodes. . However, the recording electrode created in this way has extremely weak holding strength because the recording electrode is held by adhesive and the adhesive area is about 0.05 m above the electrode width. As a result, there was a problem that the recording electrodes would fall off during printing or cleaning.The inventors of the present invention have developed a recording head with the following configuration in order to solve these problems and improve the strength of the recording electrodes. (Japanese Patent Application No. 60-250243).

FIG. 2 is a plan view showing the structure of the recording head. In the figure, 1 is an alumina ceramic layer, and 2 is a tungsten electrode.

To manufacture this recording head, first, powder of an electrode material such as tungsten is placed on an unfired ceramic layer 1.

An electrode layer 2 made of a binder, a solvent, etc. is coated to a predetermined thickness by a method such as printing, and then fired at a high temperature in a reducing atmosphere.

In this way, by simultaneously sintering the ceramic and baking the electrode material such as tungsten, a diffusion intermediate layer is formed between the ceramic layer and the electrode material layer.
A strong bond is formed, and as a result, a substrate with excellent strength can be obtained.

The electrode layer 2 baked by the above process was subjected to known photoetching or laser processing to remove unnecessary portions and form a recording electrode pattern, thereby forming a recording head.

The recording head with the above structure certainly did not have the problem of electrodes falling off, and its reliability could be greatly improved. However, because the hardness of the electrode material is not quite sufficient, for example,
As shown in the figure, when the recording head 6 is energized and the ink 5 is printed on the recording paper 3 with the recording head 6 pressing the energized transfer film 4 against the recording paper 3, the recording head 6 always moves in the pressure contact state and prints. Because of this, the tip of the recording head 6 is always in a state of friction, and therefore only the electrode material at the tip wears out, and if used for a long time, the electrode will change from the state shown in Figure 4(a) to the The state changed to that shown in FIG. 2B, and a step was created between the alumina ceramic layer 1 and the electrode layer 2, resulting in a problem of poor head touch and deterioration of the printing condition. Furthermore, the life of the head was also short.

Purpose The present invention has been made to solve the above-mentioned problems, and its purpose is to prevent deterioration in print quality due to wear of the tip of the head due to printing.

<Embodiment> Hereinafter, one embodiment of the recording head according to the present invention will be described in detail with reference to the drawings.

FIG. 1(a) shows a partial plan view of an embodiment of a recording head according to the present invention, and FIG. 1(b) shows a cross-sectional view thereof taken along line AA'. In the figure, reference numeral 7 denotes a plurality of electrode films coated on the alumina ceramic substrate 8.

The electrode film 7 is an alloy film containing nickel and phosphorus as main components.

This recording head is manufactured using an alumina ceramic substrate 8
A composite in which fine tungsten carbide powder is uniformly eutectoid and dispersed in the plating film by growing electroless nickel plating while stirring fine tungsten carbide powder in an electroless nickel plating bath containing a phosphorus component. A plated layer is formed, and then the plated layer is subjected to photoetching or laser processing to remove unnecessary parts and form a plurality of electrode batters.
The electroless nickel plating containing the phosphorus component is generally carried out as follows.

First, by soaking nickel in an acidic aqueous solution of sodium hypophosphite, the nickel surface acts as a catalyst to decompose hypophosphite anions and a dehydrogenation reaction occurs as shown in equation (1) below.

(H2PO2] → (PO2:] +2H...
・・・・・・・・・・・・(1) The atomic hydrogen generated by the reaction of equation (1) reduces the nickel cation in the aqueous solution and destroys the metal nickel, as shown in the following equation (2). do.

Ni +2H→Ni '+2H+...
(2) On the other hand, the hypophosphite anion reduces active phosphorus with activated hydrogen as shown in the following formula (3). This combines with the fractured nickel and N1-P
Alloy film is formed0 CH2PO2)-+H→H20+OH-+P0 ・1
1°°°...(3) According to this method, 28%, Ni
An alloy film of about 92% can be created.

When a plurality of electrode patterns formed by the above manufacturing procedure were heat-treated at a temperature of 400° C. for 1 hour, a highly hard film could be formed. Note that the hardness of the plating layer can be increased by heat treatment within the range of 250° C. to 550° C. for a period of 20 minutes or more and 1.5 hours or less. Electrodes manufactured in this way have very high hardness (
Hv=1000 to 1400), excellent wear resistance, and as a result, a recording head with a long life can be obtained. Since there is no need for high-temperature firing when forming the father distribution electrode film, this method is advantageous in terms of energy saving, equipment cost, etc. in terms of the construction of the manufacturing equipment.

Here, in the above embodiment, an alumina ceramic substrate with a very high Vickers hardness (1700) was used as the substrate, but considering that the Vickers hardness of the N1-P alloy film is about 650, a hardness close to that forsterei) (2MgO・5i02), mullite (
3At203・2SiO3), mica ceramics (components are Si02, At203, MgO, and 20
, B2O3, F), etc. are more preferable in terms of hardness balance.

Here, the Vickers hardness of forsterite is 800, the Vickers hardness of mullite is 700, and the Vickers hardness of mica ceramics is 650. Incidentally, the Vickers hardness of alumina is 1700, which is extremely high.

In the above examples, a composite plating layer was first formed over the entire surface, and then a recording electrode pattern was formed by removal processing such as etching. After forming the pattern, a composite plating layer may be formed, and the recording electrode pattern may be formed by removing the inverted pattern, which is an unnecessary portion, at the same time as the photoresist.

Here, in the above example, fine powder of tungsten carbide was dispersed in the plating film, but this powder may be fine particles of high hardness, such as oxides such as At203, B4C, etc.
, Tic, carbides such as Cr3C2, SiC, and Mo2C, borides such as boron nitrite and MoB, and fine particles such as WSi2.

Effects> According to the present invention as described above, the problem of electrode wear is alleviated by improving the hardness of the electrode, and reliability is significantly improved. Furthermore, processing costs were reduced.

[Brief explanation of drawings]

FIG. 1(a) is a partial plan view of an embodiment of the recording head according to the present invention, FIG. 1(b) is a cross-sectional view taken along the line A-A', and FIG. 3 is a plan view thereof, FIG. 3 is a side view thereof, and FIG. 4 is a sectional view of its tip. In the figure, 1: Alumina ceramic layer 2: Tungsten electrode layer 3: Recording paper 4: Current transfer film 5:
6: Recording head 7: Electrode film
8: Ceramic substrate agent patent attorney Sugi
Takeshi Yama (and 1 other person) Figure 1 Figure 2

Claims (1)

[Claims] 1. A recording head characterized in that a film formed by uniformly dispersing fine particles of high hardness in an alloy of Ni and P is formed on an insulating substrate material, and the film is used as an electrode.