Four-Point Probe Head
A four-point probe head for the Ossila Four-Point Probe System that can be used to measure sheet resistance, resistivity, and conductivity. The probe head features gold-coated, spring-loaded probes to provide good electrical contact, whilst reducing or eliminating damage to samples that can be caused by sharp probes.
The probes have rounded tips (unlike other probes which are sharp needles) with a radius of 0.24 mm, giving them a larger contact surface area than a needle would. This spreads the downward force being applied to the sample over a larger area. They are also mounted on springs, enabling them to retract into the probe head when making contact with a sample. This ensures that a uniform force of 60 grams is applied. A schematic of the probes is shown below.
Please note, this probe head is not suitable for silicon or other materials which naturally form insulating oxide layers. To measure such materials, the oxide layer needs to be penetrated by the probes, which may not be possible with the spring-loaded, round tipped probes utilised by this probe head.
|Probe Spacing||1.27 mm|
|Probe Radius||0.24 mm|
|Probe Stroke||1.4 mm|
|Spring Force||25 - 60 grams|
To the best of our knowledge the information provided here is accurate. However, Ossila assume no liability for the accuracy of this page. The values provided are typical at the time of manufacture and may vary over time and from batch to batch. All products are for laboratory and research and development use only, and may not be used for any other purpose including health care, pharmaceuticals, cosmetics, food or commercial applications.