Interested areas – Page 3

Photo elastic modulator

photo elastic modulator

Photo elastic modulator (PEM) is one the critical components in a phase modulated ellipsometer, which modulates phase and amplitude changes in detected signal, based on that Psi and Delta will be measured and n, k, d, and others accordingly in principle.

Transmittance/Haze/Clarity measurement-ASTM D 1003

As a simplified view, light is incident upon a sample, three processes occur: transmission, absorption, and reflection, as schematically shown in the follow figure, including retroflection, diffuse reflection, specular reflection, diffuse transmission, and specular transmission.

Major coating method and thickness control

The following are simple introduction of major coating methods and factors affecting coating process and coating thickness.

Thermally stimulated current measurement

In semiconductors based devices, defects such as dislocations, grain boundaries, and impurities can function charge traps, which in turn play important roles in determining devices properties

EM shielding effectiveness measurements by MIL-DTL-83528

Electromagnetic shielding effectiveness of EMI materials is commonly measured based on MIL-DTL-83528 or ARP 1705.

Cathodic & anodic electrochromic metal oxides

The following shaded boxes in Periodic Table of the elements refer to the transition metals whose oxides have well-documented cathodic and anodic electrochromism

A method to reduce nodules on ED copper foil

ED copper foil is broadly used in Li-ion battery and printed circuit boards in electronics industry. However, nodules are commonly observed on the surface of ED copper foil made through a conventional electro-deposition method. Patent of US 9,562.298 B2 teaches a new way to reduce the number of the nodules on the surface.

Liquid metal

For liquid metals, people may immediately think of mercury; in fact there are several other metals with melting point close to room temperature in addition to Mercury (Hg, MP=−38.8 °C, e.g. Caesium(Cs, MP=28.5 °C, Rubidium (Rb, MP=39 °C, Francium (Fr, estimated MP= at 27 °C), and Gallium (Ga, MP=30 °C). However, due to the issues of radioactivity, vapor pressure, and toxicity, etc, the practical liquid metal is typically Ga based eutectic alloy with melting point less than that of Ga.

Accuracy of Steady State Thermal conductivity measurement

The steady state method is commonly adopted to measure thermal resistance and conductivity of thermal interface materials or TIMs. A heat flow through the TIM is generated and the temperature gradient across the TIM is measured, and the thermal resistance or conductivity can be calculated through the procedure defined by ASTM standard ASTM D5470.

Polymer hard coat

Hard coat is an indispensable materials in consumer electronics, building, automobile, medical, and optics industries to add on more multifunctions to the base materials, e.g. anti-reflection (AF), anti-glare (AG), Anti-smudge, Anti-fingerprint and more.