離子轟擊聚亞醯胺薄膜

Abstract

在本論文中我們使用離子覆模機所產生的離子束轟擊聚亞醯胺 而使液晶配向，利用這種非接觸的方法大大的減少了髒顆粒與靜電的產生，改善了傳統的缺點，甚至可以結合半導體製程技術來製作multi-domain 改善其對比度。 實驗中我們改變了離子束入射角度、轟擊時間來探討其對液晶的預傾角和定向強度(A)的影響，並且針對定向強度的推導加入了預傾角的修正。 我們發現，在不同的轟擊時間條件下會有不同的A，並且在某些適當的轟擊時間會有較大的值，其改變的範圍約為10-7∼10-4 J/m2；對預傾角來說，轟擊時間加長預傾角也會慢慢增加並趨近某個角度。另一方面，改變離子的入射角度會使得A出現較大值的轟擊時間參數改變，對轟擊時間的關係曲線亦會有所不同。

Aligned liquid crystals are widely used in LC display technology. They are aligned by inducing anisotropy on the polyimide (PI). The pervasive method used in aligning liquid crystal is rubbing a PI film. It belongs to contact method and this kind of method produces some drawbacks. So we are interesting in non-contact method. Such as polarized UV radiation of PI film, atomic-beam alignment of inorganic materials and ion-beam bombard PI film. Here we describe ion-beam bombard PI film. We have replaced the rubbing roller by Ion-coater. The ion coater is an ion-beam sputter, which can produce glow discharge in the vacuum camber and then ionize the residual gas. The ionizing gas is accelerated by electric potential. Then we use ion beam to bombard the PI film with an incidence angle. The ion-beam creates directional alignment, which induces an anisotropy on the PI film, coated on a glass substrate. During our experiment, we have varied three parameters: (a) time (b) angle of incidence. We then analyze the effects of these parameters on the liquid crystal alignment properties such as anchoring strength and pretilt angle.