JPS61219101A - Thermal recording head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal recording head used in a recording method that performs recording using thermal energy.

[Prior Art] Traditionally, recording methods that use thermal energy have the advantage of being non-impact and therefore producing very little noise during recording, and in recent years have also become capable of color recording. It is gradually attracting attention.

In such a recording method, recorded information is transmitted in the form of an electrical signal to a thermal recording head, that is, an electrothermal conversion element. The electro-thermal conversion element used includes a heat generating resistance layer formed on a base and at least one pair of electrodes connected to the heat generating resistance layer.

Here, the term "substrate" refers to one that supports a heat generating resistive layer, and the substrate is simply a support with appropriate layers formed thereon, if necessary. Since thermal recording heads are generally relatively small, their heating resistance layers are of a thin film type, a thick film type, or a semiconductor type. especially,
Thin-film types consume less power than other types and have relatively good thermal responsiveness, so they are preferred as components of thermal recording heads, and their applications are gradually increasing.

Therefore, the performance required of the heat generating resistive layer of a thermal recording head is good responsiveness of heat generation to a predetermined electric signal, good thermal conductivity, and good heat resistance against its own heat generation. and various durability (t
- good durability against thermal history). Furthermore, there is a thermal recording head! ! When used in pressure contact with thermal paper or thermal transfer ink ribbon, the coefficient of friction with these is required to be small.

However, it cannot be said that the above performance is necessarily satisfactory in the heat generating resistive layer of the conventionally used thermal recording head, and further improvement of the characteristics is desired.

Furthermore, in conventional thermal recording heads, a wear-resistant layer is provided on the surface of the heat-generating resistor layer in order to improve wear resistance, but this comes at the expense of thermal responsiveness.

In addition, when using a conventional thermal recording head to record on a recording medium such as paper with a rough surface, it is necessary to press the head more strongly against the recording medium in order to record in a perfect dot shape, which reduces wear and tear. It is fast, and further improvement in performance is desired.

[Object of the Invention] In view of the above-mentioned prior art, one of the objects of the present invention has been achieved.
One object of the present invention is to provide a thermal recording head having a heat generating resistive layer with improved thermal responsiveness.

Another object of the present invention is to provide a thermal recording head having a heating resistance layer with improved thermal conductivity.

Still another object of the present invention is to provide a thermal recording head having a heating resistance layer with improved heat resistance.

Another object of the present invention is to provide a thermal recording head having a heat generating resistive layer with improved durability.

Another object of the present invention is to provide a thermal recording head having a heating resistance layer with improved wear resistance.

Still another object of the present invention is to provide a thermal recording head having a heat generating resistance layer with a small coefficient of friction.

SUMMARY OF THE INVENTION The above objects are achieved by a novel thermal recording head according to the present invention.

In the thermal recording head of the present invention, the heating resistance layer is made of an amorphous material containing carbon atoms as a matrix and halogen atoms,
The heat generating resistor layer is characterized in that the norogen atoms are distributed non-uniformly in the thickness direction.Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a partial plan view showing the structure of an embodiment of the thermal recording head of the present invention, and FIG. 2 is a sectional view taken along the line 1--2.

In the figure, 2 is a support (substrate here), 4 is a heating resistance layer, and 6.7 is a pair of electrodes. 1st
As shown in the figure, a plurality of pairs of one heat generating resistor layer 4 and a pair of electrodes 6,7 connected to the heat generating resistor layer 4 are provided, thereby forming dot-shaped effective heat generating parts 8, 8'. ,8″,
...The fists are arranged in a straight line at predetermined intervals. When the thermal recording head is in use, the heat generating resistive layer 4 side is brought into pressure contact with thermal paper or thermal transfer ink ribbon, etc., and is moved relative to the thermal paper or thermal transfer ink ribbon in the -■ direction. The heat generating resistor layer 4 that constitutes each heat generating section 8.8', 8'', . . .
A certain electrical signal is timely applied to record information through the electrodes 6 and 7, and each heat generating part generates heat based on this.
The thermal energy at this time allows recording by a thermal method, a thermal transfer method, or the like.

In the present invention, there is no particular restriction on the material of the support 2, but in practice, it is preferable that it has good adhesion to the heating resistance layer 4 and the electrodes 6 and 7 formed on its surface, and that the material for the heating resistance layer 4 is good. It is preferable that the material has good durability against the heat generated when forming the electrodes 6 and 7 and the heat generated by the heat generating resistor layer 4 during use.

The support 2 also has a heating resistance layer 4 formed on its surface.
It is preferable to have an electrical resistance larger than that of the support 2. Furthermore, a material is selected for the support 2 that has thermal conductivity that allows necessary and sufficient thermal energy to be applied to the recording medium side and that does not deteriorate responsiveness to electrical input. .

Examples of the support 2 used in the present invention include those made of inorganic materials such as glass, ceramics, and silicon, and those made of organic materials such as polyamide resin and polyimide resin.

In the present invention, the heating resistance layer 4 is made of an amorphous material containing carbon atoms as a matrix and halogen atoms. F and Cl are halogen atoms.

Br, I, etc. can be used, and these may be used alone or in combination. As the halogen atom, F and Cl are particularly preferable, and F is particularly preferable.

The content of halogen atoms in the heating resistor layer 4 is appropriately selected depending on the purpose of use of the resistor so as to obtain desired characteristics, and is preferably o or oo.

1 to 30 atom%, more preferably 0.0005 to 30 atom%
The content is 20 atomic %, preferably 0.001 to 10 atomic %.

In the present invention, the distribution of halogen atoms in the heat generating resistor layer 4 is non-uniform in the thickness direction. It may be such that the content rate gradually increases toward the side, or it may be such that the content rate decreases.Furthermore, the change in the halogen atom content may have a maximum value or a minimum value in the resistive layer 4. The change in the content of halogen atoms in the thickness direction of the heat generating resistor layer 4 may be appropriately selected so as to obtain desired characteristics.

3 to 8 show specific examples of changes in the content of halogen atoms in the film thickness direction in the heat generating resistive layer 4 of the yet-to-be invented thermal recording head. In these figures, the vertical axis is the base 2 and , t represents the thickness of the heating resistor layer 4, and the horizontal axis represents the halogen atom content C. In each figure, the vertical axis T and the horizontal The scale of axis C is not necessarily uniform, but is varied to bring out the characteristics of each figure. Therefore, in actual application, various distributions are used for each diagram based on the differences in specific numerical values.

In the thermal recording head of the present invention, an amorphous material (hereinafter referred to as "amorphous material") made of carbon as a matrix and containing halogen atoms.

ra-C: May be abbreviated as XJ. Here, X represents a halogen atom) The heating resistor layer 4 is formed by, for example, a plasma CVD method such as a glow discharge method, or a vacuum deposition method such as a sputtering method.

For example, to form the resistance layer 4 made of a-C:X by the glow discharge method, the base 2 is basically placed in a deposition chamber under reduced pressure, and carbon atoms (C) are supplied into the deposition chamber. A raw material gas for supplying C to be obtained and a raw material gas for supplying X capable of supplying halogen atoms (X) are introduced, and at this time, high frequency or micro wave is applied in the deposition chamber while changing the amount of the raw material gas for X supply. A glow discharge is generated using waves and the base 2
A layer consisting of a-C:X may be formed on the surface of.

In addition, in order to form the resistance layer 4 made of a-C:X by the sputtering method, the base 2 is basically placed in a deposition chamber under reduced pressure, and an inert material such as Ar or He is used in the deposition chamber. When sputtering a target composed of C in an atmosphere of gas or a mixed gas based on these gases, a raw material gas for X supply is introduced into the deposition chamber,
At this time, the amount introduced may be changed.

In the above method, as the raw material gas for C supply and the raw material gas for X supply, in addition to those in a gaseous state at room temperature and normal pressure, substances that can be gasified under reduced pressure can be used.

Examples of raw materials for supplying C include saturated hydrocarbons having 1 to 5 carbon atoms, ethylene hydrocarbons having 2 to 5 carbon atoms, and acetylene hydrocarbons having 2 to 4 carbon atoms.

Aromatic hydrocarbons, etc., specifically saturated hydrocarbons include methane (CH4), ethane (C2Ha), propane (
C3Hs), n-butane (n-C4HIO), pentay
(C5H12), ethylene (C2H4), propylene (C3He) as ethyl L/7 hydrocarbons
, butene-1 (C4H8), butene-2 (C4H8)
, inbutylene CC4Hs), pentene (C5H
IO), as an acetylenic hydrocarbon, acetylene (
C2H2), methylacetylene (C3H4), butyne (C4He), and aromatic hydrocarbons include benzene (CsH'e).

Examples of raw materials for supplying X include halogens, halides, interhalogen compounds, halogen-substituted hydrocarbon derivatives, etc. Specifically, the halogens include F2. C12, Br2
．． I2. Halides include HF, HCl%HBr
, HI, interhalogen compounds include BrF, ClF, C
IF3, BrF5, BrF3, IF3, IF7
, IC1, IBr, halogen-substituted hydrocarbon derivatives include CF4, CHF3, CH2F2, CH3F,
CCl4. CHCl3. CH2Cl2. CH3Cl,
CBr4. CHBr3. CH2Br2,
CH3Br, Cl4, CHH3, CH
Examples include 2I2 and CH3I.

These raw materials may be used alone or in combination.

In the heat generating resistive layer forming method as described above, in order to control the amount of halogen atoms contained in the resistive layer 4 to be formed and the characteristics of the resistive layer 4, it is necessary to control the substrate temperature, the supply amount of raw material gas, the discharge power, the deposition Set the indoor pressure etc. appropriately.

In particular, the distribution of halogen atoms in the film thickness direction of the present invention is brown-uniform.
In order to obtain a heat-generating resistor layer 4, it is preferable to change the amount of halogen atoms introduced into the deposition chamber over time, for example, by controlling a valve.

The substrate temperature is preferably selected from 20 to 1200C, more preferably 30 to 1200C, and optimally 50 to 1100C.

The supply amount of the raw material gas is determined as appropriate depending on the desired performance of the heating resistance layer and the desired film formation rate.

The discharge power is preferably o, oot~20W/crn',
More preferably, it is selected from 0.01 to 15 W/cnf, and most preferably from 0.05 to IOW/crn'.

The pressure inside the deposition chamber is preferably 10''4 to 10 Torr.
r, more preferably 10-2 to 5 Torr.

The resistive layer of the thermal recording head of the present invention obtained using the heat generating resistive layer forming method as described above has properties close to those of diamond. That is, for example, a Vickers hardness of 1800 to 5000.
Thermal conductivity 0.3-2 cal/cm e sec
*°C, resistivity 105-1011Ω-cm, thermal expansion coefficient 2
X10-5~10''''6/''Q, friction coefficient 0.15~0
．． 25. Since it has a density of 1.5 to 3.0 and contains a halogen atom, it can be obtained with extremely excellent chemical stability and thermal stability.

In the thermal recording head of the present invention, the resistance layer 4 has particularly good abrasion resistance, so the resistance layer can be made extremely thin, and a special abrasion resistant layer is not required, resulting in extremely good thermal response. you can get something.

However, it goes without saying that a layer having appropriate protection and other functions may be provided on the heat-generating resistive layer 4 of the thermal recording layer of the present invention. can be improved.

In the embodiments described above, an example is shown in which the heating resistance layer and the electrode are provided on the substrate in this order, but in the thermal recording head of the present invention, the electrode and the heating resistance layer may be provided on the substrate in this order. FIG. 9 is a partial sectional view of such a thermal recording head. In FIG. 0, 2 is a support (substrate here).
4 is a heating resistance layer, and 6.7 is a pair of electrodes.

In this case, since the more durable heat generating resistive layer is placed on the recording medium side, an extremely excellent thermal recording head can be provided even without providing an abrasion resistant layer on i.

In the above embodiments, the base is simply a support 2.
However, the substrate in the present invention may be a composite body.
As shown in the figure, the base 2 is made of a composite of a support 2a and a surface layer 2b, and the support 2a includes, for example, the first layer described above.
The support material explained in connection with the figure or even metal can be used, and as the surface layer 2b, a material with better adhesion to the resistance layer 4 formed thereon can be used. The layer 2b is made of, for example, an amorphous material having carbon atoms as a matrix, a conventionally known oxide, or the like. Such a surface layer 2b can be obtained by depositing appropriate raw materials on the support za by a method similar to the above-mentioned method for forming the heating resistor layer. Further, the surface layer 2b may be a normal glassy glaze layer.

The electrodes 6.7 in the thermal recording head of the present invention may be of any material as long as they have a predetermined conductivity, such as Au, Cu,
It is made of metal such as Al, Ag, and Ni.

Next, the outline of the method for manufacturing the thermal recording head of the present invention will be explained.

FIG. 11 is a diagram showing an example of an apparatus used when forming a heating resistance layer on the surface of a substrate. 1101 is a deposition chamber, 1102 to 1106 are gas cylinders, and 110
7 to 1111 are mass flow controllers, and 111
2-111B are inflow valves, 1117-1121
are outflow valves, 1122 to 1126 are gas cylinder valves, 1127 to 1131 are outlet pressure gauges, 1132 is an auxiliary valve, 1133 is a lever, and 1134 is a main valve.

1135 is a leak valve, 1136 is a vacuum gauge, 1137 is a base material of the thermal head to be manufactured, 1138 is a heater, 1139 is a base support means, 1140 is a high voltage power supply, 1141 is an electrode, and 1142 is a shutter. Furthermore, 1142-
1 is a target attached to the electrode 1141 when performing the sputtering method.

For example, 1102 is sealed with CF4 gas (99.9% purity or higher) diluted with Ar gas, and 1103
02F6 gas (purity 99.9) diluted with Ar gas
% or more) are sealed. Before the gas in these cylinders flows into the deposition chamber 1101, each gas cylinder 11
Make sure that valves 1122-1126 and leak valve 1135 of 02-1106 are closed, and inlet valves 1112-1116. Outflow valve 1117-1
121 and the auxiliary valve 1132 are opened, first open the main valve 1134 and open the deposition chamber tt.
When the reading of the zero-order vacuum gauge 1136 for evacuating the ot and gas pipes reaches 1.5 x 1 O-6 Torr, the auxiliary valve 1132, the inflow valves 1112 to 1116, and the outflow valves 1117 to 1121 are closed. After that, the valve of the gas pipe connected to the cylinder of the gas to be introduced into the deposition chamber 1101 is opened, and the desired gas is introduced into the deposition chamber 1101.
to be introduced within.

Next, an example of the procedure for forming the resistive layer of the thermal recording head of the present invention by the glow discharge method using the above-described apparatus will be described. Open the valve 1122 and open the gas cylinder 11.
Let the CF, /Ar gas flow out from 02, and check the outlet pressure gauge 1.
127 to 1 kg/ctn', and then gradually open the inflow valve 1112 to control the mass flow controller 1.
107, and then the outflow valve 111.
7. Gradually open the auxiliary valve 1132 to introduce CF4/Ar gas into the deposition chamber 1101. At this time, CF, /A
Adjust the mass flow controller 1107 so that the flow rate of r gas reaches the desired value, and adjust the opening degree of the main valve 1134 while checking the reading of the vacuum gauge 1136 so that the pressure inside the deposition chamber 1101 reaches the desired value. do. Then, the heater 113 is turned on so that the temperature of the substrate 1137 supported by the support means 1139 in the deposition chamber 1101 reaches a desired temperature.
8, the shutter 1142 is opened to generate glow discharge in the deposition chamber 1101. Then, the flow rate of the CF4/Ar gas is changed over time according to a pre-designed rate of change curve by manually or using an external drive motor or the like to change the opening degree of the outflow valve 1117. The content of F atoms is changed in the film thickness direction.

Next, an example of the procedure for forming the resistive layer of the thermal recording head of the present invention by sputtering using the above-described apparatus will be described. A high-purity graph eye) 11 is pre-prepared on the first electrode 4 to which a high voltage is applied by the high-voltage power supply 1140.
42-1 as a target, CF4 from the gas cylinder 1102 in the same manner as in the glow discharge method.
/Ar gas is introduced into the deposition chamber 1101 at a desired flow rate. The target 1142-1 is sputtered by opening the shutter 1142 and turning on the high voltage power supply 1140. At this time, the heater 1138 heats the base 11.
37 to a desired temperature and adjusting the opening degree of the main valve 1134 to bring the inside of the deposition chamber 1101 to a desired pressure is similar to the glow discharge method. Then, as in the case of the glow discharge method, the outflow valve 1117
The flow rate of the CF4/Ar gas is changed over time according to a pre-designed rate of change curve by changing the opening degree of the resistor layer 4, thereby changing the content of F atoms in the resistance layer 4 in the film thickness direction. .

In the case of a thermal recording head such as that shown in FIGS. 1 and 2, the formation of the heat generating resistive layer on the substrate by one or more of the glow discharge method and sputtering method is carried out over almost the entire surface of the substrate, Thereafter, by forming a conductive layer and etching the conductive layer and heat generating resistive layer using photolithography, a thermal recording head having a plurality of dot-shaped effective heat generating parts as shown in FIG. 1 can be obtained. .

Furthermore, in the case of a thermal recording head as shown in FIG.
After forming a conductive layer on a substrate in advance and etching the conductive layer using photolithography, a heat generating resistive layer is formed on the substrate by the glow discharge method and sputtering method as described above.

Two specific examples of the thermal recording head of the present invention are shown below.

Example 1: A glaze layer was provided on a support made of an alumina ceramic plate as a base, and a heat generating resistor layer was formed on the surface of the base. The deposition of a heat generating resistor layer was shown in FIG. The method was carried out using a glow discharge method using a device similar to the one described above.

CF4/Ar gas, 5 (capacity ratio), was used as the raw material gas. The conditions during the deposition were as shown in Table 1. During deposition, the opening degree of the valve is continuously changed to
By varying the flow rate of Ar gas, heating resistors having the thickness shown in Table 1 were formed.

After forming an A1 layer on the formed resistance layer by electron beam evaporation, the A1 layer is formed by photolithography.
The layer was etched into the desired shape to form multiple pairs of electrodes.

Subsequently, predetermined portions of the resistive layer were removed by photolithography using an HF-based etching solution. In this example, the size of the resistance layer between the electrode pairs is 2007 mm x 300 JLm. In this example, seven heat generating elements formed between the electrode pairs are arranged vertically. A plurality of heating resistance elements were fabricated on the same substrate.

The electrical resistance of each heating resistor element of the thus obtained thermal head was measured and found to be 90Ω.

Furthermore, an electrical pulse signal was input to each heating resistor element of the thermal head obtained in this example to measure the durability of the heating resistor element.

Note that the duty of the electrical pulse signal is 50%, and the applied voltage is 6.
V, drive frequency 0.5kHz, 1.0kHz, 2.01
cHz.

The result is a different drive! In both cases of driving with briI wavenumber, the electrical pulse signal input is 1×IQIO
The heating resistor element was not destroyed even when the temperature reached 100 times, and its resistance value hardly changed.

Next, when we printed characters with a composition of 5 dots horizontally x 7 dots vertically using thermal recording paper, we found that 2x1
Even after printing 09 characters, no problems such as missing dots occurred in the recorded characters. Furthermore, it was found that when the thermal head of this example was used as a so-called thermal transfer type in which recording is performed on recording paper via a thermal transfer ink ribbon, it also had extremely excellent durability.

Furthermore, when recording was performed using so-called type paper with a rough surface as recording paper, the thermal head of this example had extremely superior durability performance compared to conventional thermal heads. That is, compared to printing using the conventional thermal head, in which printing defects occurred after 30 million characters, in printing using the thermal head of this embodiment, no printing defects occurred after printing 30 million characters. There wasn't.

Example 2: A heating resistor layer of the same thickness was deposited in the same manner as in Example 1, except that the raw material gas was C2F8/A r = 0, 2 (capacity ratio) and the discharge power was 2 W/crn'. .

Next, when a thermal head was manufactured in the same manner as in Example 1 and an electrical pulse signal was input, the heating resistive element was not destroyed even when the electrical pulse signal input reached 1XloIO times. Further, no change in resistance value was observed.

Next, in the same manner as in Example 1, printing was performed on thermal recording paper, further printing was performed as a thermal transfer type, and further printing was performed on type paper, and as in Example 1, sufficient durability was obtained. It was confirmed that

Example 3: A glaze layer was provided on a support made of an alumina ceramic plate as a base, and a heat generating resistor layer was formed on the surface of the base. The deposition of the zero heat generating resistor layer was shown in FIG. The process was carried out by sputtering using a device manufactured by the company. 99.9% purity for sputtering target
Using the above graphite, CF4/A as the raw material gas
r gas, 5 (capacity ratio) was used. The conditions for deposition are the first
As per the table. Incidentally, during the deposition, the opening degree of the valve was continuously changed to change the flow rate of the CF4/Ar gas to form a heat generating resistor layer having the thickness shown in Table 1.

Using the resistive layer thus formed, a thermal head was produced in the same manner as in Example 1, and furthermore, in the same manner as in Example 1, an electrical pulse signal was input to the heating resistor element of the thermal head to perform printing. As a result, it was confirmed that the durability was excellent as in Example 1.

[Effects of the Invention] According to the present invention as described above, thermal responsiveness is achieved by using an amorphous material containing carbon atoms as a host and halogen atoms as the heating resistance layer.

A thermal recording head having extremely good thermal conductivity, heat resistance and/or durability, as well as chemical stability and thermal stability is provided. Also, in particular, according to the invention, 111! A thermal recording head having an excellent heat generation resistance layer with good abrasion resistance and/or a small coefficient of friction is provided.

Furthermore, according to the present invention, the content of halogen atoms in the heat generating resistive layer is distributed non-uniformly in the film thickness direction, which improves various properties such as heat storage, heat dissipation, and adhesion between the substrate and the resistive layer. characteristics can be easily realized.

[Brief explanation of the drawing]

FIG. 1 is a partial plan view of the thermal recording head of the present invention;
The figure is a sectional view taken along line ■-■. 3 to 8 are graphs showing the distribution of the content of halogen atoms in the heat generating resistor layer. 9th rl! J and 10 are partial cross-sectional views of the thermal recording head of the present invention. FIG. 11 is a diagram showing an apparatus used for manufacturing the thermal recording head of the present invention. 22 Substrate 4: Heating resistance layer 6.7: Electrode 1101: Deposition chamber 1137: Substrate Agent Patent attorney Tsumi Yamashita Figure 2 Figure 7 Figure 1O Figure 3 Figure 4 Figure D Figure 6 Figure 7 Figure S

Claims (4)

[Claims] (1) In a thermal recording head in which at least one set of a heating resistance layer and at least one pair of electrodes electrically connected to the heating resistance layer is formed on a substrate, the heating resistance layer has carbon atoms as a matrix. 1. A thermal recording head comprising an amorphous material containing halogen atoms, characterized in that the halogen atoms are distributed non-uniformly in the thickness direction in the heating resistance layer. (2) The content of halogen atoms in the heating resistance layer is 0.
The thermal recording head of claim 1, wherein the thermal recording head has a content of 0,001 to 30 at. (3) The thermal recording head according to claim 1, wherein the halogen atom is F or Cl. (4) The thermal recording head according to claim 1, wherein the substrate has a surface layer made of an amorphous material containing carbon atoms as a matrix on the side on which the heating resistor layer is formed.