Application Note | Connector Inspection
Connector Pin Inspection Using 3D Profilometry
Flatness, Pin Coplanarity and Pin-Tip Roughness from One 3D Scan
Research & Experimental Testing
Craig Leising
Visual Design & Editorial
Andrew Shore
Introduction
Electronic applications typically have challenging surfaces, angles, steps and structures to be measured during development. Whether it is circuit board flatness or microstructures on the board itself, precise measurement is crucial. As components continue to shrink and surfaces become more problematic, the measurement needs to be precise.
Importance of 3D Non-Contact Profilometry for Electronics Measurement
Because precise measurement is vital to the end use, it is crucial to monitor and control the end result. Understanding surface roughness, planarity, flatness and other parameters can lead to the best selection of processing and control measures, and ensuring quality control of such parameters relies heavily upon quantifiable, reproducible and reliable inspection. The NANOVEA 3D Non-Contact Profilometers use chromatic confocal technology with a unique capability to measure applications found in microelectronics. Where other techniques fail to provide reliable data due to probe contact, surface variation, angle, absorption or reflectivity, NANOVEA Profilometers succeed.
ℹ️ Learn more about surface profiling lab services.
Measurement Objective
In this application, the NANOVEA ST400 is used to measure the full area of a connector surface and its pins. The application was chosen for its challenging features while highlighting the measurement options of the technique. A long list of surface parameters can be calculated automatically after the surface scan; here we review a full 3D profile, the flatness of the connector base, the coplanarity of the pins and the roughness of a pin tip.
NANOVEA ST400 Standard
Optical 3D Profilometer
Results
3D Profile and Surface Flatness
2D Profile and Planarity of Pins
| Step | Maximum step height (µm) | Mean step height (µm) |
|---|---|---|
| 1 | 5031.259 | 4985.369 |
| 2 | 5039.055 | 4984.381 |
| 3 | 5023.463 | 4985.567 |
| 4 | 5069.264 | 4987.931 |
| 5 | 5017.616 | 4976.670 |
| 6 | 5051.236 | 4991.364 |
Table 1: Step heights across the pins (from Fig. 5).
Roughness of Pin Tip
| ISO 25178 parameter | Value |
|---|---|
| Sa | 2.076 µm |
| Sq | 3.125 µm |
| Sp | 11.498 µm |
| Sv | 59.893 µm |
| Sz | 71.392 µm |
| Ssk | −2.149 |
| Sku | 18.585 |
Table 2: Pin-tip roughness (from Fig. 6).
Conclusion
In this application, we have shown how the NANOVEA ST400 3D Non-Contact Profilometer can precisely characterize both the topography and the nanometer details of an electronic connector and its pins. From the 3D surface measurements, areas of interest can quickly be identified and analyzed with a wide list of measurements (dimension, roughness, finish and texture, shape, form and topography, flatness, warpage and planarity, volume and area, step height, depth and thickness, and others), and a 2D cross section can be chosen to analyze details at the nanometer range. Special areas of interest could also have been analyzed with the integrated AFM module.
NANOVEA 3D Profilometer speeds range from 20 mm/s to 1 m/s, from laboratory and research use to high-speed inspection; they can be built with custom sizes, speeds and scanning capabilities, Class 1 clean room compliance, an indexing conveyor and inline or online integration.
Frequently Asked Questions About Connector Pin Inspection
Why inspect connector pins in 3D?
Electronics have challenging surfaces, angles, steps and structures, and as components shrink, precise measurement of roughness, planarity and flatness is needed to select processes and control quality.
What was measured on the connector?
A full 3D profile of the connector and its pins, the flatness of the connector base, the coplanarity of the pins and the roughness of a pin tip.
How flat was the connector base?
The flatness of the connector base, measured over its full area with the pins excluded, was 432 µm.
How coplanar were the pins?
Maximum step heights across the row ranged from 5017.616 to 5069.264 µm, and mean step heights from 4976.670 to 4991.364 µm.
How rough was the pin tip?
Sa 2.076 µm and Sq 3.125 µm, with Sz 71.392 µm (ISO 25178).
Can this run at production speed?
NANOVEA profilometers scan from 20 mm/s to 1 m/s and can be built with custom sizes, Class 1 clean room compliance, indexing conveyors and inline or online integration.
