The probe plays a role in signal conduction during ICT,FCT,aging tests,and functional verification.Inconsistent pressing can affect the consistency of conduction and the accuracy of testing.Users often encounter various unstable phenomena in the actual process.

The common manifestation of unstable probe bonding is the fluctuation of contact resistance.When the contact pressure between the tip of the probe and the pad is insufficient,the resistance value will fluctuate.The larger the fluctuation range,the more obvious the deviation of the test data.This is commonly seen in small pads and in cases of wear on the coating.

Unstable probe bonding may manifest as intermittent breakpoints.The test screen may experience momentary disruptions.The device end may record abnormal signals.If the tip of the needle has burrs or is oxidized,it will reduce the reliability of contact.After long-term use,the spring fatigue of the fixture can also cause intermittent issues.

Unstable probe pressing may also manifest as excessive pressing.Improper pressure control can cause pad indentation.Some soft board processes are sensitive to indentation.Applying excessive force at the operation end may cause the needle body to deform.Needle tip deviation often occurs in the field.

The instability of probe bonding may also manifest as conduction delay.When the tip of the probe first makes contact,a stable circuit is not immediately established.Delayed data appears during the testing process.Such situations are usually related to the oxidation of the tip or insufficient elasticity.

Unstable probe bonding may manifest as an increase in the re-test rate of test data.The fixture exhibits abnormal points repeatedly in consecutive orders.Uneven spring force of the needle body can cause repeated errors at the same point.Fixture engineers usually handle this by replacing the probes or adjusting the height.

The instability of probe bonding can also manifest as needle tip slippage.The position of the contact point shifts.This leads to solder pad contamination.If the deviation of the needle tip angle is significant,it will cause the probe head to deviate from its trajectory.Slippage may also result in unstable test readings.

Unstable probe bonding may result in abnormal appearance.The pins may be skewed.The spring may not rebound adequately.The coating may come off.There may be stains at the pin tip.Any such appearance abnormalities may affect the bonding performance.

When dealing with the issue of unstable probe bonding,users usually conduct troubleshooting from aspects such as cleaning the tip of the probe,checking the elasticity,calibrating the fixture,and inspecting the bonding stroke.Choosing the appropriate tip shape and coating can improve the consistency of bonding.