Defective analysis of liquid crystal panels

We will introduce the observation of the shape of conductive particles in COG implementation. ICs and liquid crystal panels are implemented using the COG method with ACF (anisotropic conductive film). A resin ball is used as the core, and a metal layer (such as nickel or gold) for conductivity is deposited on its surface. During connection, the particles deform appropriately to electrically connect the IC and the panel. To confirm the degree of particle deformation and connection status, cross-sectional observations were conducted, revealing that the particle deformation was at a "medium" level, indicating an appropriate degree of deformation. By examining the deformation of conductive particles from both the planar and cross-sectional directions, we can explore the correlation with display defects. Please feel free to contact us for any inquiries regarding panel-related defects.

We will introduce a case where ICP measurement was conducted using panels before and after reliability testing, along with quantification. The liquid crystal molecules in an LCD are oriented within the panel, and the display is controlled by changes in the orientation state of the liquid crystal due to voltage. When ionic substances, such as metal elements, are present inside the panel, the liquid crystal may not drive correctly, leading to display defects. It is known that ionic substances can increase due to contamination during manufacturing or long-term use, making it important to quantify and understand them as part of panel quality. Metal ions can be quantitatively analyzed using ICP analysis, and depending on the differences in pretreatment methods and detection sensitivity, ICP-AES and ICP-MS are used selectively. [Analysis Content] ■ Comparison of metal element content using ICP-AES analysis ■ Comparison of metal element content using ICP-MS analysis For more details, please refer to the related products and catalog below.

Liquid crystal displays use various organic materials, including liquid crystals, sealing materials, encapsulants, and polarizers. Considering the material properties and degradation mechanisms of each component from a chemical perspective is important for product evaluation and failure analysis. This document presents examples of chemical analyses for the components of liquid crystal displays. 【Examples of Chemical Analysis】 ■FT-IR: Principal component analysis ■EDX: Elemental analysis ■GCMS: Liquid crystal component analysis ■HS-GCMS: Outgassing analysis (degradation analysis) and others