Toshihiko Ono

45.2: Two Point Bending of Thin Glass Substrate

The two-point bend test has been used extensively for optical fiber strength and fatigue measurements. This paper extends the theory of 2-point bending to thin glass substrates. The key advantages of the 2-point bend test are 1) the simplicity of a test fixture and its operation, 2) the uniformity of a bend stress along the width of a substrate, 3) the inverse relationship between a bend stress and parallel plate spacing, and 4) the non-contact bending.

72.2: Strength Measurements of Thin AMLCD Panels

The biaxial strength using ring-on-ring (ROR) test and uniaxial strength using 4-point bend test (4PB) were measured for 13.3″ panels with substrate thicknesses ranging from 0.25 mm to 0.5 mm. The effect of thinning process was quantified by these data along with identifying break sources using fractography. Strain gages were used to convert failure load to strength.

69.4: Superior Cuttability Performance of Jade™ Glass for Thin and Strong Mobile Displays

In addition to thermal stability of Cornings Jade™ glass, its cuttability is better suited for mobile displays with thin panels. The key focus of this paper is to provide cuttability data for thin Jade glass substrates. These data confirm that Jade offers easier panel separation than that for a-Si glasses without compromising panel strength.

48.1: Behavior of LCD Panel During Bending

When an LCD panel is subjected to pure bending, for example during strength measurement or proof testing, the question arises “does it behave as a monolith of twice the substrate thickness? or does it behave as two independent substrates?”. Both theory and experiment suggest that the panel behavior depends on how its edges are held together, i.e. well bonded? or loosely held together? Indeed, the former renders the panel nearly twice as strong and four fold as stiff as the latter. This paper will provide the analysis of the bending behavior of a two-layer laminate using St Venant flexure theory. Experimental data, using strain gages, will demonstrate that an LCD panel can behave either as a monolith of twice the substrate thickness or two independent substrates depending on how its four edges are held together in the support structure including the bezel. The paper derives appropriate equations for computing panel strength when it is bent to constant curvature or when its specimens are flexed in 4-point bending for both i) well bonded edges and ii) loosely held edges.

6.2: Mechanical Properties of Jade™ Glass Substrate for LTPS Application

Mechanical properties of Jade™ glass substrate, including ring-on-ring strength of surfaces, vertical bend strength of ground edges, dynamic fatigue constant, fracture toughness, and Youngs modulus, are presented. This high strain point glass is designed to meet low compaction requirement for low temperature polysilicon process (LTPS). Its fusion surface quality ensures pristine surfaces with high strength. Its superior edge finish leads to high edge strength. Its composition and manufacturing process eliminate the need for post-forming thermal treatment. Its intrinsic thermal stability minimizes viscous distortion during LTPS processing. Its fracture toughness is similar to that of a-Si glasses, yet its fatigue resistance is superior due, primarily, to its composition.