JPS6155626A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To shorten the time for forming a protective film and to increase its reliability by providing a recessed part at a place where metallic film wiring is to be formed in a glass substrate, embedding the metallic film wiring in this recessed part and covering it with a protective film, and thereby reducing the thickness of the protective film and lowering the film stress. CONSTITUTION:A recessed part 4 is provided at a place where the metallic film wiring 1a of a glass substrate 3 is to be formed, and the metallic film wiring 1a is embedded in the recessed part 4 not to form stepped part. Accordingly, no break is generated in the protective film 2 that covers it. An organic film that does not make stress in the film large is formed as the protective film 2. A photolithographic process is used to form the recessed part 4 of the substrate 3 face, and etching work can be completed in a short time by using hydrogen fluoride etc. for etching solution. Thus, the thickness of the protective film 2 can be reduced to lower film stress, and at the same time, mass production can be made with high reliability.

Description

【発明の詳細な説明】 〔発明の利用分野〕 本発明はガラス基板上に液晶駆動用ｒｃを直接搭載した
チップオン液晶表示素子に好適な、丈夫な金Ｂ膜配線を
有する液晶表示素子に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a liquid crystal display element having strong gold B film wiring suitable for a chip-on liquid crystal display element in which an RC for driving a liquid crystal is directly mounted on a glass substrate.

〔発明の背景〕[Background of the invention]

従来のチップオン液晶表示素子では、例えば特開昭５６
−５０３６８号公報に開示されているように、液晶表示
素子を構成するガラス基板面上に、まず金属膜配線を形
成させ、更にその上を配線保護膜で被覆して耐候性を高
めた金属膜配線に、液晶駆動用ＬＳＩを半田接続してい
た。In conventional chip-on liquid crystal display elements, for example, Japanese Patent Application Laid-Open No. 56
As disclosed in Publication No. 50368, a metal film wiring is first formed on the surface of a glass substrate constituting a liquid crystal display element, and then the metal film is further covered with a wiring protection film to improve weather resistance. A liquid crystal driving LSI was connected to the wiring by soldering.

第２図は前記のような従来の液晶表示素子の金属膜配線
を示す図で、１は金属膜配線、２は保護膜、３はガラス
基板である。FIG. 2 is a diagram showing the metal film wiring of the conventional liquid crystal display element as described above, in which 1 is the metal film wiring, 2 is a protective film, and 3 is a glass substrate.

通常、金属膜配線１は、例えば直接ガラスと接する下層
膜にはガラスとの馴染も良く、銅とも成分が相互拡散し
てよくなじむニクロムを用い、その上層に導電性の良い
銅の膜などを積層した複合膜である。しかし、銅などは
大気中、特に汚・れた大気に対しては、耐候性が余り良
くないから、この金属膜配線１を外部環境から保護する
ために、すなわち耐候性向上のために、無機質の保護膜
たとえばＳ　ｉ　Ｏ２膜で被覆することが好ましい。Normally, the metal film wiring 1 uses nichrome, which is compatible with glass and has good compatibility with copper due to mutual diffusion of components, for the lower film that is in direct contact with the glass, and a copper film with good conductivity is used as the upper layer. It is a laminated composite membrane. However, copper and other materials do not have very good weather resistance in the atmosphere, especially in dirty air, so in order to protect this metal film wiring 1 from the external environment, that is, to improve weather resistance, inorganic It is preferable to cover with a protective film such as a SiO2 film.

しかし、第２図に示すように、ガラス基板３の面上に、
金属膜配線１、無機保護膜２を逐次積層して形成させる
場合、先に形成した金属膜配線１の縁の段差部で、保護
膜２に膜切れが生じない゛で完全に金属膜配線を被覆で
きるようにするためには、この無機保護膜２の厚さを金
属膜配線１の２倍程度の厚いものにしなければならない
。これらの膜は、通常、蒸着法によって形成させるが、
膜厚が厚いと、材料が蒸気となるような高温で飛散して
来て、比較的冷たい基体上で蒸着、固化した蒸着膜の中
には大きな応力が生じ、膜の材質には相当注意している
にもかかわらず、金属膜配線のガラス基板からの剥離や
無機質保護膜表面のクランク不良などが発生しやすいと
いう欠点があった。なお、これらの不良は成膜時だけで
なく、金属膜配線に液晶駆動用ＩＣを半田付けする際の
温度上昇によっても、それぞれの材料の熱膨張の相違に
原因して生ずることがある。However, as shown in FIG. 2, on the surface of the glass substrate 3,
When forming the metal film wiring 1 and the inorganic protective film 2 by sequentially laminating them, the metal film wiring is completely formed without causing film breakage in the protective film 2 at the stepped portion of the edge of the previously formed metal film wiring 1. In order to cover the metal film wiring 1, the thickness of the inorganic protective film 2 must be approximately twice that of the metal film wiring 1. These films are usually formed by vapor deposition, but
If the film is thick, the material will scatter at such high temperatures that it becomes vapor, and large stress will be generated in the deposited film when it is deposited and solidified on a relatively cold substrate. Despite this, there are drawbacks such as peeling of the metal film wiring from the glass substrate and cranking defects on the surface of the inorganic protective film. Note that these defects may occur not only during film formation but also due to temperature rise during soldering of the liquid crystal driving IC to the metal film wiring due to differences in thermal expansion of the respective materials.

〔発明の目的〕[Purpose of the invention]

傘発明の目的は、上記のような問題のない、薄く丈夫な
耐候性保護膜付き金属膜配線を有する液晶表示素子を提
供することにある。An object of the invention is to provide a liquid crystal display element having a thin and durable metal film wiring with a weather-resistant protective film, which is free from the above-mentioned problems.

〔発明の概要〕 上記目的を達成するために本発明においては、ガラス基
板の金属膜配線を形成すべき個所に、あらかじめ凹部を
配設し、この凹部の中に金属膜配線を埋込んで、段差部
が生ぜず、従って、その上を被覆する保ＷＬ膜に膜切れ
が生ずる恐れがないようにした上で、比較的薄いために
、膜の中の応力が大きくならない無機質保護膜を形成さ
せることにした。[Summary of the Invention] In order to achieve the above object, in the present invention, a recess is provided in advance at the location where the metal film wiring is to be formed on the glass substrate, and the metal film wiring is embedded in the recess. Forming an inorganic protective film that does not create any step portions and therefore eliminates the risk of film breakage in the overlying WL film, and is relatively thin so that stress within the film does not increase. It was to be.

なお、ガラス基板面の所望の個所に凹部を形成させるた
めには、周知のホトリソグラフ法によれば良く、エツチ
ング液に、これも周知のフン化水素やフッ化アンモンの
水溶液を用いれば、比較的短時間（例えば１〜２μｍの
深さに対し数分間程度）で容易にエツチング作業を終了
することができる。これに対し、一般に無機質保護膜を
蒸着法で形成する場合には、例えばμｍあたり３０分程
度必要である。In order to form a recess at a desired location on the glass substrate surface, a well-known photolithography method may be used, and if a well-known aqueous solution of hydrogen fluoride or ammonium fluoride is used as the etching solution, a comparatively The etching operation can be easily completed in a relatively short time (for example, several minutes for a depth of 1 to 2 .mu.m). On the other hand, when an inorganic protective film is generally formed by a vapor deposition method, for example, about 30 minutes are required per μm.

〔発明の実施例〕[Embodiments of the invention]

第１図は本発明一実施例の金運膜配線とその近傍を示し
、１ａはガラス基板の凹部４の中に埋込まれた金属膜配
線で、その他の符号は第２図の場合と同様である。FIG. 1 shows the metal film wiring and its vicinity in one embodiment of the present invention, 1a is the metal film wiring embedded in the recess 4 of the glass substrate, and other symbols are the same as in FIG. 2. It is.

このような金属膜配線構造を実現するためには、例えば
下記の如くすれば良い。In order to realize such a metal film wiring structure, the following may be performed, for example.

ａニガラス基板の両面にホトレジストを塗布し、金運膜
配線を形成すべき部分のホトレジストだけを露光して除
去する。(a) Coat photoresist on both sides of a glass substrate, and remove only the photoresist in the area where the metal film wiring is to be formed by exposing it to light.

ｂ＝ニガラス基板フッ酸等、ガラス基板を食刻する液に
浸し、凹部を形成させ、水洗後、ホトレジストを除去す
る。b=Niglass substrate A glass substrate is immersed in a liquid for etching, such as hydrofluoric acid, to form recesses, and after washing with water, the photoresist is removed.

Ｃニガラス基板に配線用全屈膜を蒸着、スパ７り法など
により形成する。このとき金泥膜の膜厚は、先にガラス
基板に形成させた凹部の深さと同じにする０本実施例で
は膜厚２μｍである。A full-reflective film for wiring is formed on a C. glass substrate by vapor deposition, a spa process, or the like. At this time, the thickness of the gold mud film is 2 μm in this example, which is the same as the depth of the recess previously formed on the glass substrate.

ｄ：ホトレジストを塗布し、凹部（金属膜配線を形成す
べき個所）を被覆する部分以外のホトレジストを除去す
る。d: Apply photoresist, and remove the photoresist except for the portions covering the recesses (locations where metal film wiring is to be formed).

ｅ：金属膜を食刻し、更にホトレジストを除去する。e: Etching the metal film and removing the photoresist.

ｆ　：　Ｓ　ｉ　Ｏ，などの無機質保護膜を蒸着、スパ
ック法などにより形成する。f: An inorganic protective film such as S i O is formed by evaporation, spacing, or the like.

このようにして形成した保護膜は、厚さ１μｍ程度にす
れば、金属膜配線に対する耐候性被覆効果は十分にあり
、しかも配線の剥離、保護膜のクラック発生などの問題
は生じない。If the protective film thus formed has a thickness of about 1 μm, it will have a sufficient weather-resistant coating effect on the metal film wiring, and problems such as peeling of the wiring and cracking of the protective film will not occur.

〔発明の効果〕〔Effect of the invention〕

以上説明したように、本発明によれば、膜厚が比較的厚
い金属膜配線を形成する際にも、保護膜の厚さを薄くす
ることができるので、膜応力を下げることが出来ると共
に、保護膜形成時間が大幅に、例えば３０分程度、短縮
され、高信頼化、量産性向上の効果が得られる。As explained above, according to the present invention, even when forming a relatively thick metal film wiring, the thickness of the protective film can be made thinner, so that the film stress can be reduced, and The time required to form the protective film is significantly shortened, for example, by about 30 minutes, resulting in higher reliability and improved mass productivity.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明一実施例の金属膜配線とその近傍を示す
図、第２図は従来の液晶表示素子の金運膜配線を示す図
である。FIG. 1 is a diagram showing a metal film wiring according to an embodiment of the present invention and its vicinity, and FIG. 2 is a diagram showing a metal film wiring of a conventional liquid crystal display element.

Claims (1)

【特許請求の範囲】[Claims] ガラス基板に保護膜で被覆された金属膜配線を形成させ
た液晶表示素子において、ガラス基板の金属膜配線を形
成すべき個所に予め凹部を配設し、この凹部に金属膜配
線を埋込み、その上を保護膜で被覆したことを特徴とす
る液晶表示素子。In a liquid crystal display device in which a metal film wiring coated with a protective film is formed on a glass substrate, a recess is provided in advance at the location where the metal film wiring is to be formed on the glass substrate, and the metal film wiring is embedded in the recess. A liquid crystal display element characterized by having a top coated with a protective film.