JPH03239562A - Thermal head - Google Patents
Thermal headInfo
- Publication number
- JPH03239562A JPH03239562A JP3593490A JP3593490A JPH03239562A JP H03239562 A JPH03239562 A JP H03239562A JP 3593490 A JP3593490 A JP 3593490A JP 3593490 A JP3593490 A JP 3593490A JP H03239562 A JPH03239562 A JP H03239562A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- layer
- glaze layer
- layer electrode
- projection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000010438 heat treatment Methods 0.000 claims abstract description 65
- 239000010410 layer Substances 0.000 claims description 69
- 239000000758 substrate Substances 0.000 claims description 12
- 239000011241 protective layer Substances 0.000 claims description 6
- 230000005611 electricity Effects 0.000 claims description 5
- 238000007639 printing Methods 0.000 abstract description 16
- 229910052751 metal Inorganic materials 0.000 abstract description 9
- 239000002184 metal Substances 0.000 abstract description 9
- 238000002844 melting Methods 0.000 abstract description 7
- 230000008018 melting Effects 0.000 abstract description 6
- 238000000206 photolithography Methods 0.000 description 10
- 230000007423 decrease Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 238000005530 etching Methods 0.000 description 6
- 238000004544 sputter deposition Methods 0.000 description 6
- 239000010408 film Substances 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 238000007740 vapor deposition Methods 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910052721 tungsten Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910004479 Ta2N Inorganic materials 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 229920002120 photoresistant polymer Polymers 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000005338 heat storage Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Landscapes
- Electronic Switches (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、サーマルプリンタに搭載され、印字情報に従
って通電加熱することにより所望の印字を行なうサーマ
ルヘッドに係り、特に、その熱効率および機械強度の改
良に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal head that is installed in a thermal printer and performs desired printing by heating with electricity according to printing information, and particularly relates to a thermal head that is installed in a thermal printer and performs desired printing by heating with electricity according to printing information. Regarding improvements.
〔従来の技術］
一般に、感熱プリンタ、熱転写プリンタ等のサーマルプ
リンタに搭載されるサーマルヘッドは、例えば、複数の
発熱抵抗体を絶縁性基板上に直線的に整列配置し、印字
情報に従って前記各発熱抵抗体を選択的に通電加熱させ
て、感熱プリンタにおいては、感熱記録紙に発色記録さ
せ、また、熱転写プリンタにおいては、インクリボンの
インクを溶融して普通紙に転写記録させるようになって
いる。[Prior Art] In general, a thermal head installed in a thermal printer such as a thermal printer or a thermal transfer printer has, for example, a plurality of heat generating resistors linearly arranged on an insulating substrate, and each heat generating element is arranged in a straight line on an insulating substrate, and the heat generating resistors are arranged in a straight line on an insulating substrate. In a thermal printer, a resistor is selectively heated with electricity to record color on thermal recording paper, and in a thermal transfer printer, the ink on an ink ribbon is melted and transferred to plain paper. .
第４図は従来のこの種のサーマルヘッドの一例を示すも
のであり、アルミナ等の絶縁性基板１の上面には、蓄熱
層として機能するガラスからなるグレーズ層２が上面が
平坦面となるように絶縁性基板１のほぼ全面に８１層さ
れており、このグレーズ層２の上面には、Ｔａ２Ｎ等か
らなる複数の発熱抵抗体３が、蒸着、スパッタリング等
により全体的に積層された後にフォトリソグラフィ技術
のエツチングを行なうことにより直線状に整列して形成
されている。これらの各発熱抵抗体３の両側の上面には
、各発熱抵抗体３に対して通電するための共通電極４ａ
および個別電極４ｂがそれぞれ形成されている。これら
の各電極４ａ、４ｂは、例えば、Ａｌｌ 、Ｃｕ 、Ａ
ｕ等の軟質金属からなり、約２μｍの厚みに蒸着、スパ
ッタリング等により全体的に積層された後にフォトリソ
グラフィ技術のエツチングを行なうことにより所望の形
状のパターンに形成されている。そして、前記各発熱抵
抗体３は、前記共通電極４８および個別電極４ｂ間に、
最小印字単位たる１ドツト相当分の発熱ドツト３Ａを露
出するようにして各個独立に形成され、この発熱抵抗体
３の発熱ドツト３Ａは、前記各電極４ａ、４ｂ間に電圧
を印加することにより発熱されるようになっている。FIG. 4 shows an example of a conventional thermal head of this type, in which a glaze layer 2 made of glass that functions as a heat storage layer is placed on the top surface of an insulating substrate 1 made of alumina or the like so that the top surface is flat. 81 layers are formed on almost the entire surface of the insulating substrate 1, and on the upper surface of this glaze layer 2, a plurality of heating resistors 3 made of Ta2N etc. are laminated on the entire surface by vapor deposition, sputtering, etc., and then photolithography is performed. They are formed in linear alignment by performing an etching technique. A common electrode 4a for supplying current to each heating resistor 3 is provided on the upper surface of both sides of each heating resistor 3.
and individual electrodes 4b are formed, respectively. These electrodes 4a, 4b are made of, for example, All, Cu, A
It is made of a soft metal such as U, and is formed into a pattern of a desired shape by being entirely laminated to a thickness of about 2 μm by vapor deposition, sputtering, etc., and then etched using photolithography technology. Each heating resistor 3 has a space between the common electrode 48 and the individual electrodes 4b.
Each of the heating dots 3A of the heating resistor 3 is formed independently so as to expose the heating dots 3A equivalent to one dot, which is the minimum printing unit, and the heating dots 3A of the heating resistor 3 generate heat by applying a voltage between the electrodes 4a and 4b. It is now possible to do so.
前記絶縁性基板１、グレーズ層２、各発熱抵抗体３およ
び各電極４ａ、４ｂの上面には、各発熱抵抗体３および
電極４ａ、４ｂを保護する約７〜１０μｍの膜厚の保護
層５が積層されており、この保′ｒ！ｉ層５は、発熱抵
抗体３を酸化による劣化から保護するＳｉＯ２等からな
るほぼ２μｍの膜厚の耐酸化層６と、この酸化層６上に
積層され感熱記録紙、インクリボン等の感熱記録部材と
の接、触による摩耗から各発熱抵抗体３および電極４ａ
、４ｂを保護するＴａ２０５等からなる約５〜８μ汎の
膜厚の耐摩耗層７とから構成されており、この保護層５
は、前記各電極４ａ、４ｂの端子部以外の表面のすべて
を被覆するようになっている。この保１層５の耐酸化Ｈ
６および耐摩耗層７は、スパッタリング等の手段により
順次形成されるようになっている。On the upper surface of the insulating substrate 1, glaze layer 2, each heating resistor 3, and each electrode 4a, 4b, a protective layer 5 with a thickness of approximately 7 to 10 μm is provided to protect each heating resistor 3 and electrodes 4a, 4b. are laminated, and this protection! The i-layer 5 includes an oxidation-resistant layer 6 of approximately 2 μm thick made of SiO2, etc., which protects the heat-generating resistor 3 from deterioration due to oxidation, and a heat-sensitive recording layer such as heat-sensitive recording paper, ink ribbon, etc. that is laminated on this oxidation layer 6. Each heating resistor 3 and electrode 4a are protected from wear due to contact with other members.
, 4b, and a wear-resistant layer 7 made of Ta205 or the like and having a thickness of about 5 to 8 μm, and this protective layer 5
covers the entire surface of each electrode 4a, 4b other than the terminal portion. The oxidation resistance H of this protective layer 5
6 and the wear-resistant layer 7 are sequentially formed by means such as sputtering.
なお、実際のサーマルヘッドの製造においては、ひとつ
の絶縁性基板１上に複数個のサーマルヘッドを形成する
ようになっているため、最終工程において前記絶縁性基
板１を分割して所定数のサーマルへラドチップを得るよ
うになっている。Note that in actual manufacturing of thermal heads, multiple thermal heads are formed on one insulating substrate 1, so in the final process, the insulating substrate 1 is divided into a predetermined number of thermal heads. Now you can get Herad Chips.
前述した従来のサーマルヘッドを使用する黙転写プリン
タにおいては、このサーマルヘッドをインクリボンを介
して用紙に圧接させ、所定の印字情報に基づいて所望の
ドツトに対応する個別電極４ｂに通電することにより、
その発熱抵抗体３の発熱ドツト３Ａを発熱させ、前記イ
ンクリボンのインクを前記用紙に溶融転写させることに
より、前記用紙上に所望の印字を行なうことができる。In the above-mentioned conventional silent transfer printer using the thermal head, the thermal head is brought into pressure contact with the paper via the ink ribbon, and the individual electrodes 4b corresponding to the desired dots are energized based on predetermined printing information. ,
By causing the heating dots 3A of the heating resistor 3 to generate heat and melting and transferring the ink from the ink ribbon onto the paper, desired printing can be performed on the paper.
しかしながら、前述した従来のサーマルヘッドにおいて
は、各電極４の膜厚が約２μ扉あるため、発熱抵抗体３
の発熱ドツト３Ａと、対応する電極４の先端部間には段
部が形成されることになる。However, in the conventional thermal head described above, since the film thickness of each electrode 4 is approximately 2 μm, the heating resistor 3
A stepped portion is formed between the heating dot 3A and the tip of the corresponding electrode 4.
したがって、共通電極４ａと個別電極４ｂとの間に位置
する発熱ドツト３Ａの上部に形成される凹部は、保１１
１５により上部を被覆しても解消することができない。Therefore, the recess formed in the upper part of the heating dot 3A located between the common electrode 4a and the individual electrode 4b is
Even if the upper part is covered with No. 15, the problem cannot be solved.
この結果、インクリボン等の感熱記録部材により印字を
行なうと、この凹部は、サーマルヘッドから感熱記録部
材への熱伝導率が最も低くなる空隙を生ずるため、印加
電圧を高めないと所望の印字濃度が得られず、高電圧故
にサーマルヘッドの寿命を縮めることになる。また、電
極４は一般的にＡ１等の軟質物質により構成されている
ため、感熱記録部材のバックアップとなるプラテンの押
圧力により電極４を構成するＡＩ等の先端部上方の保ｒ
！！層５の変形や欠落あるいは剥離を生じて発熱抵抗体
３の抵抗値に変化をきたし、印字が劣化したり、サーマ
ルヘッドの信頼度や寿命を低下させる原因となっていた
。As a result, when printing is performed using a heat-sensitive recording member such as an ink ribbon, this recess creates a gap where the thermal conductivity from the thermal head to the heat-sensitive recording member is lowest, so the desired print density cannot be achieved unless the applied voltage is increased. is not obtained, and the life of the thermal head is shortened due to the high voltage. In addition, since the electrode 4 is generally made of a soft material such as A1, the pressing force of the platen, which serves as a backup for the heat-sensitive recording member, is used to maintain the upper tip of the AI or the like constituting the electrode 4.
! ! Deformation, chipping, or peeling of the layer 5 occurs, causing a change in the resistance value of the heating resistor 3, which causes deterioration of printing and decreases reliability and life of the thermal head.
前述した従来のサーマルヘッドにおける欠点を克服する
ため、第５図に示すように、グレーズ層２に縦断面円弧
状でかつ直線状に延在する突起２Ａを形成し、さらに、
この突起２Ａの頂部に縦断面ほぼ台形状の小突起２Ｂを
数μ風の厚さに形成して、共通電極４ａおよび各個別電
極４ｂの先端部を小突起２Ｂの下部に配置し、発熱ドツ
ト３Ａに凹部が形成されるのを防止したものがある。In order to overcome the drawbacks of the conventional thermal head described above, as shown in FIG.
A small protrusion 2B having an approximately trapezoidal longitudinal section and a thickness of several micrometers is formed on the top of this protrusion 2A, and the tips of the common electrode 4a and each individual electrode 4b are arranged at the bottom of the small protrusion 2B, and a heating dot is formed. There is one that prevents the formation of recesses in 3A.
このように構成すれば、それほど印加電圧を高めること
なく良好な印字強度を保持することができるが、断面台
形状の小突起２Ｂを設け、各電極の先端部を小突起２Ｂ
の頂面より低い位置に設けた場合、発熱抵抗体３をフォ
トリソグラフィ技術のエツチングにより形成する際、小
突起２Ｂの両側に段部があるため、フォトレジストの厚
みのばらつきが著しく大きいものとなるし、また、マス
クとの間に間隙が発生するほど露出精度が低下すること
から、グレーズ層２の小突起２Ｂ上に高精度にパターン
を形成できず、ショートエツチングやオーバーエツチン
グ等が生じ、抵抗値のばらつきが多発するという問題点
があった。With this configuration, it is possible to maintain good printing strength without increasing the applied voltage so much.
If the heating resistor 3 is formed at a position lower than the top surface of the photoresist, the variation in the thickness of the photoresist will be extremely large because there are steps on both sides of the small protrusion 2B when the heating resistor 3 is formed by etching using photolithography technology. In addition, as the gap between the mask and the mask increases, the exposure accuracy decreases, making it impossible to form a pattern on the small protrusions 2B of the glaze layer 2 with high precision, resulting in short etching, overetching, etc. There was a problem in that the values varied frequently.
ところで、近年、高精細高速印字あるいはカラーグラフ
ィック印字等高信頼度の得られるサーマルヘッドが要望
されているが、抵抗値のばらつきを極少にして熱効率−
を向上しないと高速高印字品質になり得°ないため、前
述した小突起２Ｂの頂面から斜面にかけて発熱抵抗体３
の発熱ドツト３Ａを形成する構成においては、発熱抵抗
体３の抵抗値が不安定になり、量産性を損うという問題
点を有している。よって、グレーズ層２の小突起２Ｂの
高さを数μ仇以上とするのが難しく、この結果、プラテ
ンとの接触性も不満足なものとなっていた。Incidentally, in recent years, there has been a demand for a thermal head that can provide high reliability for high-definition, high-speed printing or color graphic printing, but it is necessary to minimize variation in resistance and improve thermal efficiency.
Since it is not possible to achieve high speed and high printing quality without improving the heat generating resistor 3 from the top surface to the slope of the small projection 2B mentioned above,
In the configuration in which the heating dots 3A are formed, there is a problem that the resistance value of the heating resistor 3 becomes unstable, impairing mass productivity. Therefore, it is difficult to make the height of the small protrusions 2B of the glaze layer 2 several microns or more, and as a result, the contact with the platen is also unsatisfactory.
本発明は、前述した従来のものにおける問題点を克服し
、高い信頼性が得られ安定した印字品質の印字を行なう
ことのできるサーマルヘッドを提供することを目的とす
る。SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal head that overcomes the above-mentioned problems with the conventional head and that can print with high reliability and stable print quality.
前述した目的を達成するため本発明に係るサーマルヘッ
ドは、絶縁性基板上にグレーズ層を形成し、このグレー
ズ層上に、複数の発熱抵抗体ならびに各発熱抵抗体に選
択的に通電する複数の電極をそれぞれ整列状に積層して
各発熱抵抗体に発熱ドツトを形成し、これらの上方を保
Ｉｌｌにより被覆してなるサーマルヘッドにおいて、前
記グレーズ層に断面ほぼ台形状の突起を形成し、この突
起の頂部に各発熱抵抗体の発熱ドツトを位置せしめると
ともに、前記電極を２層構造とし、このうち下層電極の
みを前記グレーズ層のほぼ頂部にまで位置せしめ、上層
電極が積層されていない下層電極の単独延在部において
発生する電力損失を約１％以下としたことを特徴として
いる。In order to achieve the above-mentioned object, the thermal head according to the present invention includes a glaze layer formed on an insulating substrate, a plurality of heat generating resistors, and a plurality of heat generating resistors selectively energized on the glaze layer. In a thermal head in which electrodes are laminated in an aligned manner to form heating dots on each heating resistor, and the upper portions of these are covered with an insulator, projections having a substantially trapezoidal cross section are formed in the glaze layer, and the projections are formed on the glaze layer. The heating dots of each heating resistor are positioned at the top of the protrusion, and the electrode has a two-layer structure, of which only the lower electrode is positioned almost to the top of the glaze layer, and the lower electrode is not laminated with the upper electrode. It is characterized in that the power loss generated in the single extension portion of the wire is approximately 1% or less.
前述した構成からなる本発明によれば、グレーズ層の突
起の頂部に各発熱抵抗体の発熱ドツトを位置せしめると
ともに、２Ｈ＃Ｉ造とした電極の下層電極のみをグレー
ズ層のほぼ頂部にまで位置せしめることにより、下層電
極のみが露出している単独延在部の範囲を必要かつ最小
限の寸法に設定することができるし、また、発熱ドツト
の両側の電極との段差も小さくすることができる。According to the present invention having the above-described configuration, the heating dots of each heating resistor are positioned at the tops of the protrusions of the glaze layer, and only the lower electrode of the 2H#I electrode is positioned almost to the top of the glaze layer. By tightening the dots, it is possible to set the range of the single extension part in which only the lower electrode is exposed to the necessary and minimum size, and also to reduce the difference in level between the electrodes on both sides of the heating dot. .
以下、本発明を図面に示す実施例により説明する。 The present invention will be explained below with reference to embodiments shown in the drawings.
第１図および第２図は本発明に係るサーマルヘッドの第
１実施例を示すものであり、アルミナ等により形成され
た絶縁性基板１上には、上面を平面に形成されたガラス
からなるグレーズ層２が焼付けにより積層されており、
このグレーズ１８２上の後述する各発熱ドツト３Ａの形
成領域には、縦断面台形状の細長い直線状の突起２Ｃが
一体に形成されている。この突起２Ｃの形成は、具体的
には、フォトリソグラフィ技術のエツチングによりグレ
ーズ層２を削成することにより行なわれ、この突起２Ｃ
の頂面までの高さは約３０μ虱とされている。1 and 2 show a first embodiment of a thermal head according to the present invention. On an insulating substrate 1 made of alumina or the like, there is a glaze made of glass whose top surface is flat. Layer 2 is laminated by baking,
On the glaze 182, a long and thin linear protrusion 2C having a trapezoidal cross section is integrally formed in a region where each heating dot 3A to be described later is formed. Specifically, the formation of the protrusion 2C is performed by etching the glaze layer 2 by etching using photolithography technology.
The height to the top of the tree is said to be approximately 30μ.
前記グレーズ層２上には、その突起２Ｃ上も含めて発熱
抵抗体３が積層されている。この発熱抵抗体３は、まず
、Ｔａ２ＮやＴａ−３ｉ０２等からなる発熱抵抗体層を
蒸着、スパッタリング等によりグレーズ層２上に積層し
たうえで、この発熱抵抗体層に対しフォトリソグラフィ
技術のエツチングを行なうことにより約１０００への膜
厚に形成される。A heating resistor 3 is laminated on the glaze layer 2, including on the projections 2C. This heating resistor 3 is made by first laminating a heating resistor layer made of Ta2N, Ta-3i02, etc. on the glaze layer 2 by vapor deposition, sputtering, etc., and then etching the heating resistor layer using photolithography technology. By doing so, a film thickness of approximately 1000 µm is formed.
前記発熱抵抗体３上には、電極４が積層されている。こ
の電極４は、前記発熱抵抗体３上に積層される下層電極
４Ａと、この下層電極４Ａ上にさらに積層される上層電
極４Ｂとにより構成されており、グレーズ層２の突起２
Ｃの頂面上に形成される発熱抵抗体３の発熱ドツト３Ａ
の一側に導出される共通電極４ａ、他側に導出される複
数本の鱗別電極４ｂともそれぞれ重積された下層電極４
Ａおよび上層電極４Ｂにより構成されている。An electrode 4 is laminated on the heating resistor 3. This electrode 4 is composed of a lower layer electrode 4A laminated on the heating resistor 3 and an upper layer electrode 4B further laminated on this lower layer electrode 4A.
The heating dot 3A of the heating resistor 3 formed on the top surface of C
A lower layer electrode 4 is stacked with a common electrode 4a led out to one side and a plurality of scale electrodes 4b led out to the other side.
A and an upper layer electrode 4B.
前記下層電極４Ａは、Ｗ、ＭＯ、Ｃｒ 、Ｔｉ等からな
る硬質の高融点金属により形成されており、この下層電
極４Ａは、まず、これらの材質からなる電極層をグレー
ズ層２および各発熱抵抗体３上に蒸着、スパッタリング
等により積層したうえで、この電極層に対しフォトリソ
グラフィ技術のエツチングを行なうことにより、先端部
が突起２Ｃの頂面上に位置するようにして所定のパター
ンに形成され、グレーズＭ２の突起２Ｃの頂面上に位置
する各発熱抵抗体３の両側上に積層される。そして、相
互に間隔を隔てた共通電極４ａをなす下層電極４Ａの先
端と個別１ｉｉ！ｆ１４ｂをなす上層電極４Ｂの先端間
に発熱ドツト３Ａが形成される。この下層電極４Ａの膜
厚は、前記発熱抵抗体３と同様、約１０００八と薄く形
成されている。The lower electrode 4A is made of a hard, high melting point metal such as W, MO, Cr, Ti, etc., and the lower electrode 4A is first formed by applying an electrode layer made of these materials to the glaze layer 2 and each heating resistor. The electrode layer is laminated on the body 3 by vapor deposition, sputtering, etc., and then etched using photolithography technology to form a predetermined pattern so that the tip portion is located on the top surface of the protrusion 2C. , are laminated on both sides of each heating resistor 3 located on the top surface of the protrusion 2C of the glaze M2. Then, the tip of the lower electrode 4A forming the common electrode 4a separated from each other and the individual 1ii! Heat generating dots 3A are formed between the tips of the upper layer electrode 4B forming f14b. The lower electrode 4A has a thin film thickness of approximately 1000 mm, similar to the heat generating resistor 3.
前記下ＷＩ電極４Ａ上に積層される上層電極４Ｂは、へ
１等の良電導金属に形成されており、この上層電極４Ｂ
も、下層電極４Ａと同様、フォトリソグラフィ技術によ
り先端部がグレーズ層２の突起２Ｃ上に全く到達しない
ように所定のパターンに形成されている。この上層電極
４Ｂの膜厚は、上層電極４Ｂと比較して厚い約２μ扉に
形成されている。また、この上層電極４Ｂの幅は、前記
グレーズ層２の突起２Ｃ上における下層電極４Ａよりも
狭く形成されているこの部位の下層電に４Ａの幅と等し
くされている。The upper layer electrode 4B laminated on the lower WI electrode 4A is formed of a highly conductive metal such as metal.
Similarly to the lower electrode 4A, it is formed into a predetermined pattern by photolithography so that the tip does not reach the protrusion 2C of the glaze layer 2 at all. The film thickness of the upper layer electrode 4B is approximately 2 μm thicker than that of the upper layer electrode 4B. Further, the width of the upper layer electrode 4B is made equal to the width of the lower layer electrode 4A at this portion, which is formed narrower than the lower layer electrode 4A on the protrusion 2C of the glaze layer 2.
ところで、本実施例における電極４は、下層電極４Ａお
よび上層電極４Ｂにより２１！構造とされ。By the way, the electrode 4 in this embodiment has 21! Structure and structure.
下層電極４Ａは上層電極４Ｂの先端を越えて単独で延在
し、グレーズ層２の突起２ｃの頂面の端部にまで到達し
ている。そして、下層電極４Ａの材質は上層電極４Ｂの
材質より電気的な抵抗値が大なので、この下層電極４Ａ
が上層電極４Ｂの先端を越えて単独で延在している部位
（以下単独延在部と称する）においては、抵抗値の上昇
により電力損失が発生する。本実施例においては、この
電力損失が約１％以下となるように、下層電極４Ａが単
独延在部の長さ、厚さおよび幅寸法を設定している。The lower electrode 4A extends independently beyond the tip of the upper electrode 4B and reaches the end of the top surface of the projection 2c of the glaze layer 2. Since the material of the lower layer electrode 4A has a higher electrical resistance value than the material of the upper layer electrode 4B, this lower layer electrode 4A
In a portion where the electrode 4B extends independently beyond the tip of the upper electrode 4B (hereinafter referred to as an independent extension portion), power loss occurs due to an increase in resistance value. In this embodiment, the length, thickness, and width of the single extending portion of the lower electrode 4A are set so that this power loss is about 1% or less.
下層電極４Ａの単独延在部の長さは、発熱抵抗体３の抵
抗値の大小により支配されるものであり、例えば発熱ド
ツト３Ａの抵抗値が１０００で発熱抵抗体３のピッチが
３０００ＯＴ／インチの高精細なサーマルヘッドにおい
ては、高融点金属中で比゛抵抗の最も小さいＷ、Ｍｏを
用いても、薄膜化することにより比抵抗は約１０μΩα
程度になるし、また、発熱ドツト３Ａと下層電極４Ａの
段差をほぼ無視しうる程度にして機械的、熱的特性を改
良するためには、下ＪＥ［極４Ａの単独延在部の厚みを
０．１μ肌程度と簿くする必要がある。これを考慮して
、下Ｍ電極４Ａの幅を７０μｍ、厚さを０．１μ扉、電
力損失を１％とすると、下層電極４Ａの各単独延在部の
長さは約３５μ扉となる。一方、Ｔｉや７−ｒを用いる
と、比抵抗は約６０μΩα程度になるので、Ｗ、Ｍｏを
用いた場合の１／６になり、下層電極４Ａの単独延在部
として約６μ扉の長さしかとれず、本発明の目的にそぐ
わないものとなる。The length of the individual extending portion of the lower electrode 4A is determined by the resistance value of the heating resistor 3. For example, when the resistance value of the heating dot 3A is 1000 and the pitch of the heating resistor 3 is 3000 OT/inch. In high-definition thermal heads, even if W or Mo, which has the lowest specific resistance among high-melting point metals, is used, the specific resistance is reduced to about 10 μΩα by making the film thinner.
In addition, in order to improve the mechanical and thermal characteristics by making the level difference between the heating dot 3A and the lower electrode 4A negligible, It is necessary to keep it at around 0.1μ skin. Considering this, assuming that the width of the lower M electrode 4A is 70 μm, the thickness is 0.1 μm, and the power loss is 1%, the length of each individual extending portion of the lower electrode 4A is approximately 35 μm. On the other hand, when Ti or 7-r is used, the specific resistance is about 60μΩα, which is 1/6 of that when W or Mo is used, and the length of the door is about 6μ as an independent extension of the lower electrode 4A. However, this is not suitable for the purpose of the present invention.
このように下層電極４Ａとして高融点金属を用いる場合
は、発熱ドツト３Ａの抵抗値を数１０００４、（上とす
ることによって数１０μ次の十分な下層電極４Ａの単独
延在部の長さが得られ、かつ、電力損失の少ない省電力
のサーマルヘッドとすることができる。When a high melting point metal is used as the lower electrode 4A in this way, by setting the resistance value of the heating dot 3A to several 10004 (above), a sufficient length of the single extended portion of the lower electrode 4A on the order of several tens of microns can be obtained. It is possible to provide a power-saving thermal head with low power loss and low power loss.
ところで、下層電極４Ａの単独延在部の長さが長い場合
については、一般に、高融点金属は比抵抗が高く、かつ
スパッタリング等により薄膜化した場合にはバルクの比
抵抗よりかならず大きなものとなるため、下層電！ｆ１
４Ａの単独延在部の長さを数１００μ■〜数履とすると
、この下層電極４Ａの単独延在部の抵抗値が異常に大き
いものとなり、発熱ドツト３Ａの実効電力が減少し、エ
ネルギ密度が低下して高速印字ならびに高品質印字が達
成できず、電源等のコストアップの問題が生じる。By the way, when the length of the single extending portion of the lower electrode 4A is long, the high melting point metal generally has a high specific resistance, and when it is made into a thin film by sputtering etc., the specific resistance is always greater than the bulk specific resistance. Because of that, the lower level electricity! f1
If the length of the single extending portion of the lower electrode 4A is several hundred microns to several micrometers, the resistance value of the single extending portion of the lower electrode 4A becomes abnormally large, the effective power of the heating dot 3A decreases, and the energy density decreases. As a result, high-speed printing and high-quality printing cannot be achieved, leading to the problem of increased costs for power supplies, etc.
そこで、本実施例は、グレーズ！２に形成した突起２Ｃ
の段差を活用することで、電極の単独延在部の長さを数
１００μｍ以下と短くすることができ、発熱ドツト３Ａ
と下層電極４Ａの段差を無視することができる。Therefore, in this example, Glaze! Protrusion 2C formed on 2
By utilizing the step difference, the length of the individual extending part of the electrode can be shortened to several hundred μm or less, and the heating dot 3A
The difference in level between the lower electrode 4A and the lower electrode 4A can be ignored.
前述した本実施例のサーマルヘッドは、グレーズ層２上
にほぼ台形状の突起２Ｃを十分に高く形成し、この突起
２Ｃの頂面に各発熱抵抗体３の発熱ドツト３Ａを配設し
たものである。The thermal head of this embodiment described above has a substantially trapezoidal projection 2C formed at a sufficiently high height on the glaze layer 2, and the heating dots 3A of each heating resistor 3 are arranged on the top surface of the projection 2C. be.
各発熱ドツト３Ａの形成において、フォトリソグラフィ
技術によりパターン形成する際に最もパターン間隙が狭
くなる部位は、第２図に示すように、隣位の１対の発熱
ドツト３Δ、３Ａ問および発熱ドツト３Ａに隣接する各
１対の下層電極４Ａ。In the formation of each heating dot 3A, the portions where the pattern gap is narrowest when forming a pattern by photolithography are the adjacent pair of heating dots 3Δ, 3A and the heating dot 3A, as shown in FIG. each pair of lower layer electrodes 4A adjacent to .
４Ａ間である。これらのパターンにおける狭い間隙の部
位は、できるだけ平坦面としてパターン形成用マスク板
に最大限密着できることにより高精度で歩留り向上を達
成できることになるので、本実施例においては、グレー
ズ層２の突起２Ｃの平坦に形成された頂面上に発熱抵抗
体３、ならびに、発熱抵抗体３と同様的１０００人と厚
さの薄い高融点金属からなる下層電極４Ａと発熱抵抗体
３の境界部を配設して突起２Ｃの頂面上に発熱ドツト３
八を形威し、グレーズ層２の突起２Ｃの斜面の外部に、
グレーズ層２の突起２Ｃ上における発熱抵抗体３の幅お
よび下層電極４Ａの幅よりも狭くし、かつ厚さ約２μ卯
の上層Ｎ極４Ｂを配設することにより、フォトリソグラ
フィ技術による加工のばらつきにより精度低下や製造歩
留りの低下が生じないようにできる。It is between 4A. The narrow gap portions in these patterns can be made as flat as possible so that they can be brought into close contact with the pattern forming mask plate as much as possible, thereby achieving high precision and yield improvement. A heating resistor 3 and a boundary between the heating resistor 3 and a lower electrode 4A made of a thin high melting point metal similar to the heating resistor 3 are arranged on the flat top surface. A heating dot 3 is placed on the top surface of the protrusion 2C.
8, on the outside of the slope of the protrusion 2C of the glaze layer 2,
By making the width of the heating resistor 3 on the protrusion 2C of the glaze layer 2 narrower than the width of the lower layer electrode 4A, and by arranging the upper layer N-pole 4B with a thickness of approximately 2 μm, variations in processing due to photolithography technology can be reduced. Therefore, it is possible to prevent a decrease in accuracy and a decrease in manufacturing yield from occurring.
このように、本実施例のサーマルヘッドにおいては、グ
レーズ層２の突起２Ｃの高さを従来よりも著しく高く形
成しても、前述した特有の電極４の構成とすることによ
り、フォトリソグラフィ技術における加工の精度、歩留
り低下がなく、しかも、グレーズ層２に突起２Ｃを形成
することにより抵抗値が大きい下層電極４Ａの単独延在
部の長さを著しく短くできるので、感熱記録部材のバッ
クアップとなるプラテンとの接触性が極めて良好なもの
となるし、また、電力損失を小さく、しかも、機械的強
度ならびに熱的特性の安定した高信頼度のサーマルヘッ
ドとすることができる。In this way, in the thermal head of this embodiment, even if the height of the protrusion 2C of the glaze layer 2 is formed to be significantly higher than that of the conventional one, the unique structure of the electrode 4 described above makes it possible to use the photolithography technique. There is no reduction in processing accuracy or yield, and by forming the protrusions 2C on the glaze layer 2, the length of the single extending portion of the lower layer electrode 4A, which has a large resistance value, can be significantly shortened, so it serves as a backup for the thermosensitive recording member. This provides extremely good contact with the platen, reduces power loss, and provides a highly reliable thermal head with stable mechanical strength and thermal characteristics.
なお、本発明は前述した実施例に限定されるものではな
く、必要に応じて種々の変更が可能である。例えば、第
３図に示すように、グレーズ層２に突起２Ａと小突起２
Ｂを形成したうえで第１実施例のような下層電極４Ａお
よび上層電極４Ｂの構成を採用してもよいし、また、第
３図に示すように、上層電極４Ｂの先端を小突起２Ｂの
上下方向の中間位置にまで到達するようにしてもよい。Note that the present invention is not limited to the embodiments described above, and various changes can be made as necessary. For example, as shown in FIG.
Alternatively, the structure of the lower layer electrode 4A and the upper layer electrode 4B as in the first embodiment may be adopted after forming the upper layer electrode 4B, or as shown in FIG. It may also be possible to reach an intermediate position in the vertical direction.
〔発明の効果］
以上説明したように本発明のサーマルヘッドによれば、
高い信頼が得られ安定した印字品質の印字を行なうこと
ができるという優れた効果を奏する。[Effects of the Invention] As explained above, according to the thermal head of the present invention,
It has the excellent effect of being able to print with high reliability and stable print quality.
１・・・絶縁性基板、２・・・グレーズ層、２Ａ、２Ｃ
・・・突起、２Ｂ・・・小突起、３・・・発熱抵抗体、
３Ａ・・・発熱ドツト、４・・・電極、４ａ・・・共通
電極、４ｂ・・・個別電極、４Ａ・・・下層電極、４Ｂ
・・・上層電極、５・・・保護層。1... Insulating substrate, 2... Glaze layer, 2A, 2C
...Protrusion, 2B...Small protrusion, 3...Heating resistor,
3A... Heat generating dot, 4... Electrode, 4a... Common electrode, 4b... Individual electrode, 4A... Lower layer electrode, 4B
... Upper layer electrode, 5... Protective layer.
第１図および第２図は本発明に係るサーマルヘッドの第
１実施例を示すものであり、第１図は縦断面図、第２図
は保護層を省略した平面図、第３図は本発明の第２実施
例を示す縦断面図、第４図および第５図はそれぞれ従来
のサーマルヘッドを示す縦断面図である。1 and 2 show a first embodiment of the thermal head according to the present invention, FIG. 1 is a longitudinal sectional view, FIG. 2 is a plan view with the protective layer omitted, and FIG. 3 is a main view. A longitudinal sectional view showing a second embodiment of the invention, and FIGS. 4 and 5 are longitudinal sectional views showing a conventional thermal head, respectively.
Claims (1)
に、複数の発熱抵抗体ならびに各発熱抵抗体に選択的に
通電する複数の電極をそれぞれ整列状に積層して各発熱
抵抗体に発熱ドットを形成し、これらの上方を保護層に
より被覆してなるサーマルヘッドにおいて、前記グレー
ズ層に断面ほぼ台形状の突起を形成し、この突起の頂部
に各発熱抵抗体の発熱ドットを位置せしめるとともに、
前記電極を２層構造とし、このうち下層電極のみを前記
グレーズ層のほぼ頂部にまで位置せしめ、上層電極が積
層されていない下層電極の単独延在部において発生する
電力損失を約１％以下としたことを特徴とするサーマル
ヘッド。A glaze layer is formed on an insulating substrate, and on this glaze layer, a plurality of heat generating resistors and a plurality of electrodes that selectively conduct electricity to each heat generating resistor are laminated in an aligned manner so that each heat generating resistor generates heat. In a thermal head formed by forming dots and covering the upper part of these with a protective layer, a protrusion having a substantially trapezoidal cross section is formed in the glaze layer, and the heating dots of each heating resistor are positioned at the top of the protrusion. ,
The electrode has a two-layer structure, of which only the lower electrode is positioned almost to the top of the glaze layer, so that the power loss occurring in the independent extension of the lower electrode on which the upper electrode is not laminated is about 1% or less. Thermal head is characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3593490A JPH03239562A (en) | 1990-02-16 | 1990-02-16 | Thermal head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3593490A JPH03239562A (en) | 1990-02-16 | 1990-02-16 | Thermal head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03239562A true JPH03239562A (en) | 1991-10-25 |
Family
ID=12455855
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3593490A Pending JPH03239562A (en) | 1990-02-16 | 1990-02-16 | Thermal head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03239562A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008213316A (en) * | 2007-03-05 | 2008-09-18 | Tdk Corp | Thermal head, photographic printing equipment, and manufacturing method for thermal head |
| JP2012111049A (en) * | 2010-11-19 | 2012-06-14 | Rohm Co Ltd | Thermal print head and method of manufacturing the same |
| CN102555515A (en) * | 2010-11-19 | 2012-07-11 | 罗姆股份有限公司 | Thermal print head and method of manufacturing the same |
| JP2021100826A (en) * | 2016-09-15 | 2021-07-08 | ローム株式会社 | Thermal print head |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54140547A (en) * | 1978-04-24 | 1979-10-31 | Matsushita Electric Ind Co Ltd | Thin film type thermal head |
| JPH01286864A (en) * | 1988-05-14 | 1989-11-17 | Fuji Xerox Co Ltd | Thermal head |
-
1990
- 1990-02-16 JP JP3593490A patent/JPH03239562A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54140547A (en) * | 1978-04-24 | 1979-10-31 | Matsushita Electric Ind Co Ltd | Thin film type thermal head |
| JPH01286864A (en) * | 1988-05-14 | 1989-11-17 | Fuji Xerox Co Ltd | Thermal head |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008213316A (en) * | 2007-03-05 | 2008-09-18 | Tdk Corp | Thermal head, photographic printing equipment, and manufacturing method for thermal head |
| JP2012111049A (en) * | 2010-11-19 | 2012-06-14 | Rohm Co Ltd | Thermal print head and method of manufacturing the same |
| CN102555515A (en) * | 2010-11-19 | 2012-07-11 | 罗姆股份有限公司 | Thermal print head and method of manufacturing the same |
| JP2021100826A (en) * | 2016-09-15 | 2021-07-08 | ローム株式会社 | Thermal print head |
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