JP3560311B2 - Recording head and recording apparatus using the same - Google Patents

Description

【００４３】
表１から明らかなように、記録素子基板のバンプ状電極のヤング率と駆動素子基板のバンプ状電極のヤング率との差が２．８×１０^１０Ｐａ以上であれば、接合の信頼性等の点で、より好ましいことがわかる。
【００４４】
このような組み合わせのバンプ状電極を有する記録ヘッドでは、例えば記録素子基板が故障して記録素子基板を交換する必要が生じても、この交換によって電気的接続の信頼性を損なうことなく交換を行うことが可能になる。
【００４５】
図７〜図１３は、図１，図４および図６にて説明した記録素子ユニットの製造工程を説明する図である。
【００４６】
まず、発熱抵抗体層１６２０となるＨｆＢ_２ を３５０μｍ、Ｔｉを５０μｍ、電極１６０８を形成するＡｌを６０００μｍの厚さでそれぞれスパッタリング法により基材１６０４上に形成する（図７）。上記で形成された膜上に、フォトリソグラフィ法を用いて、レジストを塗布、露光、現像してパターニングし、さらに上記の膜をエッチングにより配線形成し、その後、レジストを剥離する。さらに、上記で形成された基板上に、上記と同様なフォトリソグラフィ法を用いてレジストをパターニングしさらに、Ａｌをエッチングにより部分的に除去してヒータ部を形成する。レジストは、エッチング後剥離する（図８）。
【００４７】
次に、ヒータ耐酸化層および層間絶縁層１６５４としてのＳｉＯ_２ 層９０００μｍ、耐キャビテーション層１６５５としてのＴａ５０００μｍを連続スパッタにより基板全面に成膜する（図９）。さらに、前述したような方法によりレジストをパターニングし、Ｔａをエッチングにより部分的に除去して、Ｔａパターンを形成する。また、ＳｉＯ_２ を同様な方法によりパターニングする。耐インク層、層間絶縁層としての有機絶縁膜２．５μｍを塗布し、前述と同様な方法でパターン形成するかもしくは、感光性のある有機絶縁膜を塗布して、露光、現像してパターン形成する（図１０）。
【００４８】
次に、電気メッキ下引き層として、Ｃｕ３０００μｍ、Ｔｉ５００μｍを基板全面に成膜する（図１１）。
【００４９】
メッキ形成用のレジストを塗布し、露光、現像する。レジストは東京応化製のＰＭＥＲ−ＡＲ９００を用い通常の塗布、露光、現像を行い、その後、酸素プラズマアッシングを行う。例えば、レジスト膜厚は、２５ミクロンとする。アッシング条件は、真空度１ｔｏｒｒ、酸素ガス厚５００ｓｃｃｍ、基板温度３５度、パワー１ｋｗ、アッシング時間１０から２０分で行うと、上記のレジストパターンの断面形状は、逆テーパー状に形成される。このテーパー角はアッシング時間によりある程度調整可能であり、時間を長くすると逆テーパー状態が大となる。
【００５０】
上記のようにして形成したメッキレジストを用いて、電気メッキ法により、Ａｕ，Ｎｉ，Ｃｕ，Ｐｔ，Ｐｄ，Ｉｎ，半田等のめっきを数ミクロンから数十ミクロン形成する。最後にレジストを剥離する（図１２）。
【００５１】
以上の工程によって製造された記録素子基板のバンプ状電極の詳細を図１３に示す。
【００５２】
一方、駆動素子基板については、保持体上に、前述してきたような方法と同様に、配線電極パターン、層間距離パターン、バンプ状電極パターンを形成することができる。
【００５３】
このようにして形成した記録素子基板および駆動素子基板を用いて構成した記録素子ユニットはバンプ状電極を除き図４に示すものと同様のものとなる。
【００５４】
図１４は以上のようにして作成した記録素子基板にインクを吐出させるための吐出口およびこれに連通する液路とを形成するための天板１６６１を接合して形成される記録素子ユニット、および同様の駆動素子基板からなるインクジェット駆動ユニットを接続して形成されるインクジェットヘッドを示す図である。
【００５５】
また、図１５は天板１６６１を接合した部分のインクジェットヘッドの詳細を示す分解斜視図であり、インク吐出１６６２およびこれに連通する液路１６６３、さらには共通液室１６６４が形成される。各液路１６６３にはヒータ１６０７が形成され、また、天板１６６１にはインク供給のための供給口１６６６が設けられる。
【００５６】
図１６は本実施形態のインクジェット記録装置の一例を示す図である。
【００５７】
図１６において、記録媒体としての記録シート５０３は、給紙ローラ５０２によって、上下に所定間隔を置いて設置されたシート送りローラ５０１まで搬送され、矢印方向にシート送りされる。また、上記記録シートの全面にはガイド軸５１３に沿って移動するキャリッジ５１０が設けられている。キャリッジ５１０は、前述したインクジェットヘッド５１２の吐出口が記録シート５０３の上面に所定の間隔をおいて対向するようにしてインクジェットヘッドを支持する支持体である。図示例では、キャリッジ５１０上にインクジェットヘッド５１２が搭載されている。なお、キャリッジ５１０は、キャリッジ駆動モータによりベルト５０１等の伝達機構を介して往復駆動される。
【００５８】
記録に際しては、キャリッジ５１０の記録シート幅方向の走査に同期して、インクジェットヘッド５１２の吐出口から記録シートへ向けてインクが吐出されることにより記録が行われる。
【００５９】
図１７は上記インクジェット記録装置を用いたプリンタの一例を示す斜視図である。基本的に図１６に示したインクジェット記録装置を外装ケース１０００によって覆うことによってプリンタが構成される。ケース１０００には、走査部１２００等が設けられている。
【００６０】
図１８はインクジェット記録装置の他の例を示す概略斜視図である。図１６に示す装置と異なる点は、インクジェットヘッドは搬送される記録紙の記録幅分に対応したインク吐出口を備え固定された点である。すなわち、キャリッジを往復移動させる必要がなく、そのため機構が簡単で、かつ高速記録が可能となる。本発明は、このように比較的長尺のヘッドを用いる場合に、特に有効である。
【００６１】
（その他）
なお、本発明は、特にインクジェット記録方式の中でも、インク吐出を行わせるために利用されるエネルギとして熱エネルギを発生する手段（例えば電気熱変換体やレーザ光等）を備え、前記熱エネルギによりインクの状態変化を生起させる方式の記録ヘッド、記録装置において優れた効果をもたらすものである。かかる方式によれば記録の高密度化，高精細化が達成できるからである。
【００６２】
その代表的な構成や原理については、例えば、米国特許第４７２３１２９号明細書，同第４７４０７９６号明細書に開示されている基本的な原理を用いて行うものが好ましい。この方式は所謂オンデマンド型，コンティニュアス型のいずれにも適用可能であるが、特に、オンデマンド型の場合には、液体（インク）が保持されているシートや液路に対応して配置されている電気熱変換体に、記録情報に対応していて核沸騰を越える急速な温度上昇を与える少なくとも１つの駆動信号を印加することによって、電気熱変換体に熱エネルギを発生せしめ、記録ヘッドの熱作用面に膜沸騰を生じさせて、結果的にこの駆動信号に一対一で対応した液体（インク）内の気泡を形成できるので有効である。この気泡の成長，収縮により吐出用開口を介して液体（インク）を吐出させて、少なくとも１つの滴を形成する。この駆動信号をパルス形状とすると、即時適切に気泡の成長収縮が行われるので、特に応答性に優れた液体（インク）の吐出が達成でき、より好ましい。このパルス形状の駆動信号としては、米国特許第４４６３３５９号明細書，同第４３４５２６２号明細書に記載されているようなものが適している。なお、上記熱作用面の温度上昇率に関する発明の米国特許第４３１３１２４号明細書に記載されている条件を採用すると、さらに優れた記録を行うことができる。
【００６３】
記録ヘッドの構成としては、上述の各明細書に開示されているような吐出口，液路，電気熱変換体の組合せ構成（直線状液流路または直角液流路）の他に熱作用部が屈曲する領域に配置されている構成を開示する米国特許第４５５８３３３号明細書，米国特許第４４５９６００号明細書を用いた構成も本発明に含まれるものである。加えて、複数の電気熱変換体に対して、共通するスリットを電気熱変換体の吐出部とする構成を開示する特開昭５９−１２３６７０号公報や熱エネルギの圧力波を吸収する開孔を吐出部に対応させる構成を開示する特開昭５９−１３８４６１号公報に基いた構成としても本発明の効果は有効である。すなわち、記録ヘッドの形態がどのようなものであっても、本発明によれば記録を確実に効率よく行うことができるようになるからである。
【００６４】
さらに、記録装置が記録できる記録媒体の最大幅に対応した長さを有するフルラインタイプの記録ヘッドに対しても本発明は有効に適用できる。そのような記録ヘッドとしては、複数記録ヘッドの組合せによってその長さを満たす構成や、一体的に形成された１個の記録ヘッドとしての構成のいずれでもよい。
【００６５】
加えて、上例のようなシリアルタイプのものでも、装置本体に固定された記録ヘッド、あるいは装置本体に装着されることで装置本体との電気的な接続や装置本体からのインクの供給が可能になる交換自在のチップタイプの記録ヘッド、あるいは記録ヘッド自体に一体的にインクタンクが設けられたカートリッジタイプの記録ヘッドを用いた場合にも本発明は有効である。
【００６６】
また、本発明の記録装置の構成として、記録ヘッドの吐出回復手段、予備的な補助手段等を付加することは本発明の効果を一層安定できるので、好ましいものである。これらを具体的に挙げれば、記録ヘッドに対してのキャッピング手段、クリーニング手段、加圧或は吸引手段、電気熱変換体或はこれとは別の加熱素子或はこれらの組み合わせを用いて加熱を行う予備加熱手段、記録とは別の吐出を行なう予備吐出手段を挙げることができる。
【００６７】
また、搭載される記録ヘッドの種類ないし個数についても、例えば単色のインクに対応して１個のみが設けられたものの他、記録色や濃度を異にする複数のインクに対応して複数個数設けられるものであってもよい。すなわち、例えば記録装置の記録モードとしては黒色等の主流色のみの記録モードだけではなく、記録ヘッドを一体的に構成するか複数個の組み合わせによるかいずれでもよいが、異なる色の複色カラー、または混色によるフルカラーの各記録モードの少なくとも一つを備えた装置にも本発明は極めて有効である。
【００６８】
さらに加えて、以上説明した本発明実施例においては、インクを液体として説明しているが、室温やそれ以下で固化するインクであって、室温で軟化もしくは液化するものを用いてもよく、あるいはインクジェット方式ではインク自体を３０℃以上７０℃以下の範囲内で温度調整を行ってインクの粘性を安定吐出範囲にあるように温度制御するものが一般的であるから、使用記録信号付与時にインクが液状をなすものを用いてもよい。加えて、熱エネルギによる昇温を、インクの固形状態から液体状態への状態変化のエネルギとして使用せしめることで積極的に防止するため、またはインクの蒸発を防止するため、放置状態で固化し加熱によって液化するインクを用いてもよい。いずれにしても熱エネルギの記録信号に応じた付与によってインクが液化し、液状インクが吐出されるものや、記録媒体に到達する時点ではすでに固化し始めるもの等のような、熱エネルギの付与によって初めて液化する性質のインクを使用する場合も本発明は適用可能である。このような場合のインクは、特開昭５４−５６８４７号公報あるいは特開昭６０−７１２６０号公報に記載されるような、多孔質シート凹部または貫通孔に液状又は固形物として保持された状態で、電気熱変換体に対して対向するような形態としてもよい。本発明においては、上述した各インクに対して最も有効なものは、上述した膜沸騰方式を実行するものである。
【００６９】
さらに加えて、本発明インクジェット記録装置の形態としては、コンピュータ等の情報処理機器の画像出力端末として用いられるものの他、リーダ等と組合せた複写装置、さらには送受信機能を有するファクシミリ装置の形態を採るもの等であってもよい。
【００７０】
【発明の効果】
以上の説明から明らかなように、本発明によれば、２つのユニットの一方のバンプ状電極を形成する材料のヤング率を、他方の電極のヤング率より小さくしたので、ヤング率の相対的に小さい一方のバンプ状電極の変形に対する剛性がヤング率の相対的に大きい他方のバンプ状電極の変形に対する剛性よりも小さなものとなり、その接合の際にはヤング率の相対的に小さい一方のバンプ状電極自ら変形することにより他方のバンプ状電極に変形を生じさせずに済む。そして、上記ヤング率の小さい方のバンプ状電極が設けられた一方のユニットが新たなものに交換され、これが他方のユニットと接合する場合には、他方のユニットのバンプ状電極には変形が生じていないので、未接合状態が生じることはない。このようなバンプ状電極を用いることにより、記録ヘッド内における電気的接続の信頼性低下を防止できる。
【図面の簡単な説明】
【図１】（Ａ）および（Ｂ）は、インクジェットヘッドを構成する記録素子基板および駆動素子基板をそれぞれ示す平面図およびその縦断面図である。
【図２】図１に示される記録素子基板の縦断面図である。
【図３】記録素子基板と駆動素子基板との電気的接続のための構成の一例を示す図である。
【図４】記録素子基板と駆動素子基板との電気的接続のための構成の一例を示す図である。
【図５】（Ａ）〜（Ｅ）は、図４に示す電気的接続のためのバンプ状電極の一従来例の接合およびそれによる変形を説明するための図である。
【図６】（Ａ）〜（Ｅ）は、本発明の一実施形態に係るバンプ状電極の形状およびその接合を説明するための図である。
【図７】（Ａ）および（Ｂ）は、本発明の一実施形態に係る記録素子基板の製造工程を説明する図であり、（Ａ）は平面図であり、（Ｂ）は（Ａ）のｂ−ｂ′線の縦断面図である。
【図８】（Ａ）〜（Ｃ）は、本発明の一実施形態に係る記録素子基板の製造工程を説明する図であり、（Ａ）は平面図であり、（Ｂ）は（Ａ）のｂ−ｂ′線の縦断面図であり、（Ｃ）は（Ａ）のｃ−ｃ′線の縦断面図である。
【図９】（Ａ）〜（Ｃ）は、本発明の一実施形態に係る記録素子基板の製造工程を説明する図であり、（Ａ）は平面図であり、（Ｂ）は（Ａ）のｂ−ｂ′線の縦断面図であり、（Ｃ）は（Ａ）のｃ−ｃ′線の縦断面図である。
【図１０】（Ａ）〜（Ｃ）は、本発明の一実施形態に係る記録素子基板の製造工程を説明する図であり、（Ａ）は平面図であり、（Ｂ）は（Ａ）のｂ−ｂ′線の縦断面図であり、（Ｃ）は（Ａ）のｃ−ｃ′線の縦断面図である。
【図１１】（Ａ）〜（Ｃ）は、本発明の一実施形態に係る記録素子基板の製造工程を説明する図であり、（Ａ）は平面図であり、（Ｂ）は（Ａ）のｂ−ｂ′線の縦断面図であり、（Ｃ）は（Ａ）のｃ−ｃ′線の縦断面図である。
【図１２】（Ａ）〜（Ｃ）は、本発明の一実施形態に係る記録素子基板の製造工程を説明する図であり、（Ａ）は平面図であり、（Ｂ）は（Ａ）のｂ−ｂ′線の縦断面図であり、（Ｃ）は（Ａ）のｃ−ｃ′線の縦断面図である。
【図１３】図７〜図１２に示した上記製造工程において形成されるバンプ状電極を示す概略断面図である。
【図１４】本発明の一実施形態に係るインクジェットヘッドを示す縦断面図である。
【図１５】上記インクジェットヘッドのインク吐出部を中心に示す分解斜視図である。
【図１６】上記実施形態のインクジェットを用いたインクジェット記録装置を示す概略斜視図である。
【図１７】上記記録装置を用いたプリンタの外観斜視図である。
【図１８】本発明の他の実施形態に係るインクジェットヘッドを用いたインクジェット記録装置を示す概略斜視図である。
【符号の説明】
１６０１ ベース板
１６０４，１６０５ 基材
１６３１ａ，１６３１ｂ，１６３２ａ，１６３２ｂ バンプ状電極
１６６１ 天板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording head and a recording apparatus using the same, and more particularly, to an electrical connection between a recording element unit having a recording element formed thereon and a driving element unit having a driving element for driving the recording element in the recording head. It is about.
[0002]
[Prior art]
As a recording element unit and a driving element unit which constitute a recording head used in a recording apparatus, for example, those shown in FIGS. 1A and 1B are known. 1A and 1B, a recording element unit 161 and a driving element unit 162 constitute a recording head of an ink jet system, and are formed on a common base plate 1601. That is, the recording element unit 161 is configured by arranging a heater 1607, segment electrode wiring 1608, common electrode electrode 1613, common electrode wiring 1614, and the like on a substrate 1604 made of silicon (Si). Is formed by disposing an integrated circuit 1606 of a driving element including a transistor and the like, electrode wirings 1617 and 1618, and the like on a similar substrate 1605. Each of the substrates 1604 and 1605 is connected to a common base plate 1601 by an adhesive or the like. The recording element unit 161 and the driving element unit 162 are electrically connected by bonding wires 1616.
[0003]
FIG. 2 shows the details of the recording element unit 161. FIG. 2 is a longitudinal sectional view of the recording element substrate shown in FIG. A heater 1607 that generates heat energy used for ejection in the recording element unit 161 connects the segment electrode wiring 1608 and the comment electrode wiring 1614 to the heating resistor layer 1620, and has an ink-resistant layer 1654, an anti-cavitation layer, etc. By using the heat energy generated by the heater 1607, bubbles can be generated in the ink, and the ink can be ejected by the pressure of the bubbles.
[0004]
As shown in FIGS. 1 and 2, by providing a plurality of heating elements in the recording element unit, it is possible to obtain an ink jet recording apparatus that performs recording of a plurality of dots at the same time, and to increase the recording speed. . In particular, today, demands for high-density, high-speed printing are high, and it has become common to simultaneously print a plurality of dot array lines arranged in the main scanning direction. The recording unit arranged in has appeared.
[0005]
By the way, when a plurality of heating elements are arranged in the recording element unit and printing of a plurality of dots is performed at the same time, on / off of each of the heating elements must be individually controlled. As a means for performing such control, a driving element including a transistor or the like as shown in FIGS. 1 and 2 is used. Although this drive element can be formed in the recording element unit, it is usually formed on an independent substrate as shown in FIGS. 1 and 2, and is connected to the recording element unit. This is because when the recording element and the driving element are formed on an integrated substrate, even if a defect occurs in any part of the recording element or the driving element, the function of the entire substrate is disturbed. This is because there is a problem that it must be performed for each integrated substrate.
[0006]
Conventionally, when a recording element substrate and a driving element substrate are separately provided as described above, as a technique for electrically connecting the recording element substrate and the driving element substrate, as shown in FIGS. As shown in FIG. 3, a method using an electrical connection member 1630 for making electrical connection between the substrates 1604 and 1605 is known.
[0007]
However, in the wire bonding method, in order to avoid contact or the like between adjacent micro-electrodes, the connection pitch of each element on the recording element substrate or the driving element substrate must be some distance. Therefore, if the sizes of the recording element substrate and the driving element substrate are determined, the maximum number of connection parts is inevitably determined. However, in the wire bonding method, since this pitch dimension is usually as large as about 0.2 mm, the number of connection parts must be reduced. Conversely, this means that if the number of connecting portions on the printing element substrate or the driving element substrate is determined, the size of the printing element substrate and the driving element substrate must be extremely long.
[0008]
Further, in the method using the electrical connection member as shown in FIG. 3, there is a demand for miniaturization and cost reduction.
[0009]
To solve such a problem, a configuration for electrical connection shown in FIG. 4 has been proposed. That is, electrical connection is made by bump-shaped electrodes 1630a and 1630b provided so as to protrude at the end of the electrode wiring. This has advantages, such as extremely high density, easy downsizing, and low cost, as compared with the above-described wire bonding method and the method using an electrical connection member.
[0010]
One embodiment of a recording head using this method includes a wiring for supplying an electric signal to a heater, a holding body for holding the wiring, and a printing element provided on the holding body and having a wiring for supplying an electric signal. And a bump-shaped electrode connected to an end of the wiring and provided so as to protrude, and corresponding to a heater as an energy generating unit of the recording element, and communicating with a discharge port for discharging ink. Is provided.
[0011]
In another aspect, a wiring for supplying an electric signal to the heater, a holding member for holding the wiring, a printing element provided on the holding member and having a wiring for supplying the electric signal, A printing element unit including a bump-shaped electrode provided so as to be protruded and a driving element unit having a driving element for driving the recording element and a wiring connected to the driving element. The bump-shaped electrode is connected to the wiring of the electric drive element substrate, and a liquid path communicating with a discharge port for discharging ink is provided corresponding to a heater as an energy generating unit of the recording element. ing.
[0012]
In the above configuration, the pattern wiring and the bump-shaped electrode are as follows. The pattern wiring of the printing element and the driving element substrate is formed on the surface of the holder. Further, when a protective layer is formed on the surface of the holder for protection and insulation of the pattern wiring, it is necessary to expose a sufficient area for forming the bump-shaped electrode. The pattern wiring is formed of, for example, a conductive material such as Al. A bonding portion composed of a bump-shaped electrode is formed on the pattern wiring of the recording element substrate.
[0013]
The bonding portion composed of the bump-shaped electrode is for making an electrical connection with another circuit substrate. That is, the electrical connection is made by directly joining with a joining portion such as another circuit board. As the material of the bump-shaped electrode, a metal such as Cu, Ni, Au, Cr, Rh or an alloy composed of a combination thereof is used. Further, the bump-shaped electrode and the pattern wiring may be formed integrally from the beginning of manufacture, or the bump-shaped electrode may be formed on the pattern wiring after forming the pattern wiring.
[0014]
The bonding is performed as shown in FIG. 4 using the above-mentioned bump-shaped electrodes. Here, the joining is particularly effective when the joining portion of the recording element substrate and the joining portion of the drive element substrate are joined by a pressure welding method. In addition, joining by a metal or an alloy, joining by a method other than a metal and an alloy may be used, or a combination of these and a pressure welding method may be used.
[0015]
In this method, as already disclosed, the tip of the bump-shaped electrode caused by the curvature or unevenness of the surface of the recording element substrate or the driving element substrate absorbs the positional variation and the electrical connection between the recording element substrate and the driving element substrate. It is important to ensure reliability.
[0016]
However, in general, the electric circuit board is not a perfect flat plate, but has some curvature or unevenness. In addition, the electric circuit board may be curved due to heat generated during driving. As described above, when the curvature or unevenness is large, a connection failure may occur in the electrical connection between the printing element substrate and the driving element substrate.
[0017]
In order to prevent this, it is desirable to strengthen the connection or to use a substrate having no curvature or unevenness, and therefore, there is a problem that the cost becomes extremely high. It is expected that the influence of the above-mentioned curvature will increase as the heater array direction of the printing element unit becomes longer. In order to solve such a problem, it has been proposed to form a bump-shaped electrode through a layer having a large thickness. According to this method, bonding can be performed relatively well.
[0018]
[Problems to be solved by the invention]
However, there is a problem that is not sufficiently solved by the above method. That is, in a configuration in which a large number of such bump-shaped electrodes are arranged on a substrate and pressed against each other to obtain electrical bonding, compared to the reliability of the first pressure bonding, during repeated pressing several times, The certainty is reduced, and a connection failure may occur during several repetitions.
[0019]
This is because when the bump-shaped electrodes are joined together, the bump-shaped electrodes are plastically deformed in a direction along the cross section to increase the reliability of the pressure contact, so that one of the substrates is replaced. Subsequent studies have clarified that, when pressure welding is repeated, the reliability of the connection is reduced due to deformation of the bump-shaped electrode.
[0020]
On the other hand, in the printing element unit and the printing apparatus using the same, the durability of the printing element unit is generally shorter than the useful life of the printing apparatus.
[0021]
Therefore, in the recording apparatus, when the recording element unit fails, it is desirable to replace the recording element unit.However, the failed recording element unit is replaced as simply as possible, and even after replacement, the same as before the replacement. Reliability must be ensured.
[0022]
In general, the life of the printing element substrate is shorter than that of the driving element substrate. The reason for this is that the lifespan of a large number of printing elements arranged in the printing element unit is much shorter than the driving elements of the driving element unit.
[0023]
Under such circumstances, in the above-described printing apparatus, the printing element units, particularly, among them, the printing element substrate is frequently replaced. Further, when the recording element substrate is replaced, it is not necessary to replace the driving element substrate. Also, from the viewpoint of cost, the driving element substrate is a high cost because it is a module made of a semiconductor element. Even when the recording element substrate is replaced, the driving element substrate can be used without replacement. It has been demanded.
[0024]
However, as already described, it has been found that in the connection configuration using the bump-shaped electrode, the reliability of the bonding is reduced during several times of press-bonding, and an element in an unbonded state occurs. .
[0025]
FIGS. 5A to 5E are schematic side views schematically showing this state.
[0026]
As shown in FIGS. 5A and 5B, when the recording element substrate 1604 and the driving element substrate 1605 are connected to each other, the bump electrodes 1630a and 1630b are pressed against each other. At this time, for example, if the three bump-shaped electrodes 1630b of the printing element substrate 1604 have a variation in height or misalignment, or unevenness of the substrate, the bump-shaped electrode 1630a of the driving element substrate is The electrode 1630b is deformed into an irregular shape due to a variation in height or the like. Then, when the recording element substrate 1604 is removed for replacement (FIG. 5C) and another substrate 1604 is newly attached (FIG. 5B), it is caused by pressure contact with the previous substrate 1604. Due to the irregular deformation, an unbonded bump-like electrode may be generated (FIG. 5E).
[0027]
The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a recording head capable of preventing a decrease in the reliability of pressure contact of a bump-shaped electrode due to repeated joining between substrates and a recording head used in the recording head. A recording device is provided.
[0028]
Therefore, according to the present invention, there is provided a print head including: a print element unit provided with a print element; and a drive element unit provided with a drive element for driving the print element of the print element unit. The unit and the drive element unit each have a pair of bump-shaped electrodes for making an electrical connection between the two units by joining each other, and form one bump-shaped electrode of the two units. Young's modulus of the material forming the other bump-shaped electrode is smaller than that of the material forming the other bump-shaped electrode. One unit provided with the bump-shaped electrode formed of a material having a relatively small Young's modulus is a unit to be replaced. It is characterized by the following.
[0030]
According to the above configuration, since the Young's modulus of the material forming one of the bump-shaped electrodes of the two units is smaller than the Young's modulus of the other electrode, the rigidity of one of the bump-shaped electrodes against deformation is reduced. Is less than the rigidity against deformation, and at the time of joining, one of the bump-shaped electrodes having a small Young's modulus is deformed by itself, thereby preventing the other bump-shaped electrode from being deformed. Then, when one of the units provided with the bump electrodes having the smaller Young's modulus is replaced with a new one, and the new unit is joined to the other unit, the bump-shaped electrodes of the other unit have the same structure. Since there is no deformation in the direction along the cross section, the length of the bump-shaped electrode does not become non-uniform, there is no gap between the bump-shaped electrode of the partner unit and no gap between the two units. No joining condition occurs.
[0031]
Here, the above-described Young's modulus will be described.
[0032]
The Young's modulus is, for example, a stress acting on a cross section of a rod-shaped object represented by T, a contraction per unit length of the rod-shaped object represented by ε, and when a relation of T = Eε is established within a proportional limit, E = Refers to T / ε. That is, the fact that the Young's modulus (E = T / ε) of the rod-shaped object A is smaller than the Young's modulus of the rod-shaped object B means that if the stresses T acting on the rod-shaped objects A and B are the same, the rod-shaped objects A This means that the contraction ε per unit length of the object A is large. Therefore, in the present invention, when the rod-shaped object A and the rod-shaped object B are butt-joined to each other, the same stress T acts on the two, and deformation occurs only on the rod-shaped object A having a relatively small Young's modulus. No deformation occurs on the side of the rod-shaped object B having a relatively large Young's modulus.
[0035]
In short, in the present invention, it is assumed that a bump-shaped electrode for making an electrical connection between two units is deformed at the time of bonding, and the deformation is applied only to the bump-shaped electrode provided in one unit, Only the deformed unit is replaced, and the new unit and the undeformed unit are joined to ensure the reliability of the electrical connection between them.
[0036]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0037]
FIGS. 6A to 6E show deformation states of the bump-shaped electrodes of the recording element substrate and the drive element substrate according to the embodiment of the present invention when the bonding and detachment of the substrates are repeated. FIG.
[0038]
The units of the printing element substrate and the driving element substrate of the present embodiment are the same as those shown in FIG. 4 and those described above with respect to this configuration, and differ only in the material of the bump-shaped electrodes shown in FIG. Therefore, illustration and description of those similar elements are omitted.
[0039]
Bump shape of this embodiment electrode Is that the Young's modulus of the material of the bump-shaped electrode 1631b of the recording element substrate 1604 is smaller than the Young's modulus of the material of the bump-shaped electrode 1631a of the driving element substrate 1605. Accordingly, the rigidity of the bump-shaped electrode 1631b of the recording element substrate 1604 against deformation in the pressure contact direction becomes smaller than that of the bump-shaped electrode 1631a of the driving element substrate 1605.
[0040]
As a result, even if, for example, the bump-shaped electrode 1631b of the recording element substrate 1604 to be attached first has a variation in height (FIG. 6A), when the bump-shaped electrode 1631a on the drive element side is pressed against the bump-shaped electrode 1631a, the electrode itself is pressed. The bump-shaped electrode 1631a is deformed and hardly deforms (FIGS. 6B and 6C). Thus, at the time of the next joining, no unjoining occurs between the bump-shaped electrodes, and as at the time of the first joining, the bump-shaped electrodes 1631b on the recording element substrate side are deformed, so that the bump-shaped electrodes on the driving element side are deformed. 1631a can hardly be deformed.
[0041]
When citing a combination of materials for the bump-shaped electrode applied to the present invention, when the bump-shaped electrode having a relatively small Young's modulus is made of a material mainly composed of gold, such as pure gold or a gold alloy, The bump-shaped electrode having a relatively large Young's modulus is made of zinc or invar brass, tungsten, titanium, iron, copper, nickel, platinum, palladium, molybdenum, phosphor bronze, a combination thereof, or an alloy thereof. More specific combinations of materials for the bump-shaped electrodes are shown in Table 1 below.
[0042]
[Table 1]

[0043]
As is clear from Table 1, the difference between the Young's modulus of the bump-shaped electrode of the recording element substrate and the Young's modulus of the bump-shaped electrode of the driving element substrate is 2.8 × 10 ¹⁰ It can be seen that if it is Pa or more, it is more preferable in terms of bonding reliability and the like.
[0044]
In a print head having such a combination of bump-shaped electrodes, for example, even if the print element substrate fails and the print element substrate needs to be replaced, the replacement is performed without deteriorating the reliability of the electrical connection. It becomes possible.
[0045]
FIGS. 7 to 13 are views for explaining a manufacturing process of the recording element unit described with reference to FIGS. 1, 4 and 6.
[0046]
First, HfB to be the heating resistor layer 1620 ₂ Is formed to a thickness of 350 μm, Ti to 50 μm, and Al for forming the electrode 1608 to a thickness of 6000 μm on the base material 1604 by a sputtering method (FIG. 7). Using a photolithography method, a resist is applied, exposed, developed, and patterned on the film formed above to pattern the film, and further, a wiring is formed by etching the film, and then the resist is removed. Further, on the substrate formed as described above, a resist is patterned by using the same photolithography method as described above, and Al is partially removed by etching to form a heater portion. The resist is peeled off after etching (FIG. 8).
[0047]
Next, SiO as a heater oxidation-resistant layer and an interlayer insulating layer 1654 is formed. ₂ A layer of 9000 μm and Ta 5000 μm as an anti-cavitation layer 1655 are formed on the entire surface of the substrate by continuous sputtering (FIG. 9). Further, the resist is patterned by the method described above, and Ta is partially removed by etching to form a Ta pattern. In addition, SiO ₂ Is patterned by the same method. Apply an organic insulating film of 2.5 μm as an ink-resistant layer and an interlayer insulating layer and form a pattern by the same method as described above, or apply a photosensitive organic insulating film and expose and develop to form a pattern. (FIG. 10).
[0048]
Next, Cu 3000 μm and Ti 500 μm are formed on the entire surface of the substrate as an electroplating undercoat layer (FIG. 11).
[0049]
A plating resist is applied, exposed, and developed. The resist is subjected to ordinary coating, exposure, and development using PMER-AR900 manufactured by Tokyo Ohka, and thereafter, oxygen plasma ashing is performed. For example, the resist film thickness is 25 microns. The ashing conditions are as follows: a vacuum degree of 1 torr, an oxygen gas thickness of 500 sccm, a substrate temperature of 35 degrees, a power of 1 kw, and an ashing time of 10 to 20 minutes, the cross-sectional shape of the above resist pattern is formed in an inverse tapered shape. The taper angle can be adjusted to some extent by the ashing time, and the longer the time, the larger the reverse taper state.
[0050]
Using the plating resist formed as described above, plating of Au, Ni, Cu, Pt, Pd, In, solder, or the like is formed from several microns to several tens microns by electroplating. Finally, the resist is stripped (FIG. 12).
[0051]
FIG. 13 shows details of the bump-shaped electrodes of the recording element substrate manufactured by the above steps.
[0052]
On the other hand, for the driving element substrate, a wiring electrode pattern, an interlayer distance pattern, and a bump-shaped electrode pattern can be formed on the holder in the same manner as described above.
[0053]
The recording element unit formed by using the recording element substrate and the driving element substrate thus formed is the same as that shown in FIG. 4 except for the bump-shaped electrodes.
[0054]
FIG. 14 shows a recording element unit formed by joining a top plate 1661 for forming an ejection port for ejecting ink to the recording element substrate prepared as described above and a liquid path communicating with the ejection port, and FIG. 4 is a diagram illustrating an inkjet head formed by connecting inkjet drive units each including a similar drive element substrate.
[0055]
FIG. 15 is an exploded perspective view showing the details of the ink jet head at the portion where the top plate 1661 is joined. An ink discharge 1662, a liquid passage 1663 communicating therewith, and a common liquid chamber 1664 are formed. A heater 1607 is formed in each liquid passage 1663, and a supply port 1666 for supplying ink is provided in the top plate 1661.
[0056]
FIG. 16 is a diagram illustrating an example of the ink jet recording apparatus of the present embodiment.
[0057]
In FIG. 16, a recording sheet 503 as a recording medium is conveyed by sheet feed rollers 502 to sheet feed rollers 501 installed at predetermined intervals above and below, and is fed in the direction of the arrow. A carriage 510 that moves along the guide shaft 513 is provided on the entire surface of the recording sheet. The carriage 510 is a support that supports the inkjet head such that the ejection openings of the inkjet head 512 face the upper surface of the recording sheet 503 at a predetermined interval. In the illustrated example, an inkjet head 512 is mounted on a carriage 510. The carriage 510 is reciprocated by a carriage drive motor via a transmission mechanism such as a belt 501.
[0058]
At the time of recording, the recording is performed by ejecting ink toward the recording sheet from the ejection port of the inkjet head 512 in synchronization with the scanning of the carriage 510 in the recording sheet width direction.
[0059]
FIG. 17 is a perspective view showing an example of a printer using the ink jet recording apparatus. Basically, a printer is configured by covering the ink jet recording apparatus shown in FIG. The case 1000 includes a scanning unit 1200 and the like.
[0060]
FIG. 18 is a schematic perspective view showing another example of the ink jet recording apparatus. The difference from the apparatus shown in FIG. 16 is that the ink jet head is provided with ink ejection ports corresponding to the recording width of the recording paper being conveyed, and is fixed. That is, there is no need to reciprocate the carriage, so that the mechanism is simple and high-speed recording is possible. The present invention is particularly effective when such a relatively long head is used.
[0061]
(Other)
In addition, the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for causing ink to be ejected, particularly in an ink jet recording system. The present invention provides an excellent effect in a print head and a printing apparatus of a type that causes a change in state. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.
[0062]
Regarding the typical configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or the liquid path holding the liquid (ink). Applying at least one drive signal corresponding to the recording information and providing a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, thereby causing the electrothermal transducer to generate thermal energy, and This is effective in that film boiling occurs on the heat-acting surface of the liquid, and as a result, air bubbles in the liquid (ink) corresponding to this drive signal one-to-one can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of the liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.
[0063]
As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, liquid path, and electrothermal converter as disclosed in the above-mentioned specifications, A configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which a is bent, is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.
[0064]
Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by combining a plurality of recording heads, or a configuration as a single recording head that is integrally formed.
[0065]
In addition, even with the serial type printer as in the above example, the recording head fixed to the main unit or attached to the main unit enables electrical connection with the main unit and supply of ink from the main unit. The present invention is also effective when a replaceable chip-type recording head or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.
[0066]
Further, it is preferable to add a discharge recovery means for the print head, a preliminary auxiliary means, and the like as the configuration of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. Specifically, heating is performed on the recording head by using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer or another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.
[0067]
Regarding the type or number of print heads to be mounted, for example, in addition to one provided for single color ink, a plurality of print heads are provided corresponding to a plurality of inks having different print colors and densities. May be used. That is, for example, the printing mode of the printing apparatus is not limited to the printing mode of only the mainstream color such as black, but may be any of integrally forming the printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.
[0068]
In addition, in the embodiments of the present invention described above, the ink is described as a liquid, but an ink that solidifies at room temperature or below and that softens or liquefies at room temperature may be used, or In general, in the ink jet method, the temperature of the ink itself is adjusted within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. A liquid may be used. In addition, in order to positively prevent the temperature rise due to thermal energy by using it as energy for changing the state of the ink from the solid state to the liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to the case of using an ink having a property of liquefying for the first time. In such a case, the ink is held in a state of being held as a liquid or solid substance in the concave portion or through hole of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, it may be configured to face the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.
[0069]
In addition, as the form of the ink jet recording apparatus of the present invention, in addition to a form used as an image output terminal of an information processing device such as a computer, a form of a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function are adopted. Or the like.
[0070]
【The invention's effect】
As apparent from the above description, according to the present invention, the Young's modulus of the material forming one of the bump-shaped electrodes of the two units is made smaller than the Young's modulus of the other electrode. The rigidity of one of the small bump-shaped electrodes against deformation becomes smaller than the rigidity of the other bump-shaped electrode having relatively large Young's modulus, and the other bump-shaped electrode with relatively small Young's modulus is used for bonding. By deforming the electrode itself, the other bump-shaped electrode does not need to be deformed. Then, one of the units provided with the bump electrodes having the smaller Young's modulus is replaced with a new one, and when this is joined to the other unit, the bump electrodes of the other unit are deformed. No unjoined state is generated. By using such bump-shaped electrodes, it is possible to prevent a decrease in the reliability of the electrical connection in the recording head.
[Brief description of the drawings]
FIGS. 1A and 1B are a plan view and a longitudinal sectional view showing a recording element substrate and a driving element substrate constituting an ink jet head, respectively.
FIG. 2 is a longitudinal sectional view of the recording element substrate shown in FIG.
FIG. 3 is a diagram illustrating an example of a configuration for electrical connection between a printing element substrate and a driving element substrate.
FIG. 4 is a diagram illustrating an example of a configuration for electrical connection between a printing element substrate and a driving element substrate.
5 (A) to 5 (E) are views for explaining bonding of a conventional example of a bump-like electrode for electrical connection shown in FIG. 4 and deformation thereof.
FIGS. 6A to 6E are diagrams for explaining the shape of a bump-shaped electrode and the bonding thereof according to an embodiment of the present invention.
FIGS. 7A and 7B are diagrams for explaining a manufacturing process of a recording element substrate according to an embodiment of the present invention, wherein FIG. 7A is a plan view, and FIG. FIG. 4 is a vertical sectional view taken along line bb ′ of FIG.
FIGS. 8A to 8C are diagrams illustrating a process for manufacturing a recording element substrate according to an embodiment of the present invention, wherein FIG. 8A is a plan view, and FIG. (C) is a vertical cross-sectional view taken along the line cc 'of (A).
FIGS. 9A to 9C are diagrams illustrating a process for manufacturing a recording element substrate according to an embodiment of the present invention, FIG. 9A is a plan view, and FIG. (C) is a vertical cross-sectional view taken along the line cc 'of (A).
FIGS. 10A to 10C are diagrams illustrating a manufacturing process of a printing element substrate according to an embodiment of the present invention, wherein FIG. 10A is a plan view, and FIG. (C) is a vertical cross-sectional view taken along the line cc 'of (A).
FIGS. 11A to 11C are diagrams illustrating a manufacturing process of a recording element substrate according to an embodiment of the present invention, wherein FIG. 11A is a plan view, and FIG. (C) is a vertical cross-sectional view taken along the line cc 'of (A).
12 (A) to 12 (C) are views for explaining a manufacturing process of the recording element substrate according to one embodiment of the present invention, wherein FIG. 12 (A) is a plan view and FIG. 12 (B) is (A). (C) is a vertical cross-sectional view taken along the line cc 'of (A).
FIG. 13 is a schematic cross-sectional view showing a bump-shaped electrode formed in the manufacturing process shown in FIGS. 7 to 12.
FIG. 14 is a longitudinal sectional view showing an inkjet head according to an embodiment of the present invention.
FIG. 15 is an exploded perspective view mainly showing an ink ejection unit of the inkjet head.
FIG. 16 is a schematic perspective view showing an ink jet recording apparatus using the ink jet of the embodiment.
FIG. 17 is an external perspective view of a printer using the recording apparatus.
FIG. 18 is a schematic perspective view showing an inkjet recording apparatus using an inkjet head according to another embodiment of the present invention.
[Explanation of symbols]
1601 Base plate
1604, 1605 Base material
1631a, 1631b, 1632a, 1632b Bump-shaped electrode
1661 Top plate

Claims (4)

A print head having a print element unit provided with a print element and a drive element unit provided with a drive element for driving the print element of the print element unit,
The recording element unit and the driving element unit each have a pair of bump-shaped electrodes for making an electrical connection between the two units by bonding to each other, and one of the bump-shaped electrodes of the two units. Young's modulus of the material forming the electrode is rather smaller than the Young's modulus of the material forming the other bump electrodes,
The recording head according to claim 1, wherein one of the units provided with the bump-shaped electrodes formed of a material having a relatively small Young's modulus is a unit to be replaced . Said unit being exchanged, the recording head according to claim 1, characterized in that the recording element unit. 3. The recording element according to claim 1, wherein the recording element of the recording element unit has a thermal energy generator that generates bubbles in the ink using thermal energy and discharges the ink by the pressure of the bubbles. Recording head. A recording apparatus comprising: the recording head according to claim 1 ; and a support that supports the recording head so as to face one surface of a recording medium at a predetermined interval.

Images