Memory cards of various sizes are commonly employed as storage media for cell phones, digital cameras, recorders, and more. These cards are inserted into slots in these devices, with the card’s surface roughness affecting the smoothness and ease of insertion.
Memory card.
The surface roughness of memory cards is a major contributor to their commercial value so it is an important measurement criterion in quality control (QC). When conventional roughness testers are used to conduct QC evaluation of memory cards, there can be measurement limitations. Conventional testing devices must be in contact with the card’s surface, generally only measuring height (roughness) along one line of motion.
Evident’ Solution
The Evident LEXT™ OLS5000 3D scanning laser confocal microscope enables precise 3D profile measurement without contacting the surface being examined. OLS5000 microscope users can acquire clear, high-resolution images of memory cards’ surfaces, applying three-dimensional roughness parameters that comply with ISO 25178.
The OLS5000 microscope’s wide surface evaluation is adept at revealing seemingly random irregularities and provides extensive measurement information not offered by traditional roughness testers that only measure along a single line.
The system also incorporates a standard automatic stage function that facilitates the acquisition of data across multiple surface points, registering the coordinates of measurements and using the imaging stitching function.
(1) Sample A (Objective: 20X. Effective field of vision: 640 µm)
Measurement point 1–Memory card sample A surface roughness evaluation.
Measurement point 2–Memory card sample A surface roughness evaluation.
Measurement point 3– Memory card sample A surface roughness evaluation.
Table 1. Memory card sample A surface roughness measurements
| Parameter |
Sq [µm] |
Sa [µm] |
Sz [µm] |
Sku [µm] |
| Point 1 |
3.5 |
2.897 |
26.501 |
2.518 |
| Point 2 |
3.766 |
3.033 |
30.446 |
2.966 |
| Point 3 |
3.626 |
2.955 |
25.5 |
2.741 |
| Average |
3.631 |
2.962 |
27.482 |
2.742 |
| Standard deviation |
0.133 |
0.068 |
2.615 |
0.224 |
(2) Sample B (Objective: 20X. Effective field of vision: 640 µm)
Measurement point 1–Memory card sample B surface roughness evaluation.
Measurement point 2–Memory card sample B surface roughness evaluation.
Measurement point 3–Memory card sample B surface roughness evaluation.
Table 2. Memory card sample B surface roughness measurements
| Parameter |
Sq [µm] |
Sa [µm] |
Sz [µm] |
Sku [µm] |
| Point 1 |
1.608 |
1.259 |
17.946 |
3.833 |
| Point 2 |
1.579 |
1.241 |
18.158 |
3.86 |
| Point 3 |
1.646 |
1.296 |
22.166 |
3.936 |
| Average |
1.611 |
1.265 |
19.423 |
3.876 |
| Standard deviation |
0.034 |
0.028 |
2.378 |
0.053 |
Products Used for This Application
Image Credit: Evident Corporation - Industrial Microscopy
The Evident LEXT™ OLS5000 laser scanning confocal microscope enables users to make contactless, nondestructive 3D observations and measurements with ease. Fine shapes can be measured at the submicron level at the touch of a button.
This user-friendliness is combined with cutting-edge features to offer an acquisition speed that is four times faster than its previous incarnation. Customers with larger samples may benefit from the use of LEXT long working distance objectives, alongside the implementation of an extended frame option that accommodates samples as tall as 210 mm.
This information has been sourced, reviewed and adapted from materials provided by Evident Corporation - Industrial Microscopy.
For more information on this source, please visit Evident Corporation - Industrial Microscopy