Surface Roughness Evaluation of Memory Cards

Micron-scale shape measurement using a laser microscope

Memory card

(1) Application

Memory cards vary in size and are widely used as storage media for digital cameras, cell phones, recorders, etc. The cards are inserted into slots on these devices, and the card’s surface roughness affects the smoothness of insertion. Because the cards’ surface roughness contributes to their commercial value, it is an important measurement criterion in quality control. Quality control using conventional roughness testers may have measurement limitations because these testers require contact with the surface being tested and typically only measure height (roughness) along a single line of motion.

(2) Solution

The Olympus LEXT OLS5000 3D scanning laser microscope enables high-resolution and high-precision 3D profile measurement without contacting the examined surface. It enables users to obtain clear, high-resolution images using a confocal optical system. The system uses three-dimensional roughness parameters that comply with ISO 25178, enabling contactless surface-area evaluation. Its wide surface evaluation is more suitable for seemingly random irregularities and provides more measurement information than conventional roughness testers that measure along a single line. The OLS5000 microscope includes the standard auto stage function that facilitates data acquisition of multiple points on the surface by registering measurement coordinates and using the imaging stitching function.

Images

(1) Sample A (Objective: 20X. Effective field of vision: 640 µm）

(2) Sample B (Objective: 20X. Effective field of vision: 640 µm）