The original ICT probe design was created to address the probe-related challenges of In-Circuit Testing. The introduction of the ICT probe series made available the first fundamentally new probe technology in 30 years, benefiting test personnel by surpassing performance levels obtainable from previous industry standard designs. The Titanium Pro ICT Series continues the evolution of high performance probe design by refining the ICT concept to achieve an even greater performance threshold. Previously unattainable results are realized through a stronger, more rugged design and platings designed to handle the harshness of today's In-Circuit Test environments.

Probe Design and Performance
Probe design is focused on ensuring internal contact between the plunger and barrel, attempting to prevent elevated and large variations in resistance caused by poor internal contact. This performance aspect is important because relatively small variations in resistance, voltage and/or current must be measured on the UUT during test. If the variation in the probe's resistance is greater than the allowable signal tolerance, a good product is rejected.

Until recently, to ensure a positive electrical contact, probes have been designed using a bias technology. These designs include bias ball, bias plunger and bias spring. As with all bias technology, the goal of the design is to force the plunger off-center to ensure contact with the barrel. Obviously, this does not enhance pointing accuracy. It also forces the plunger to contact the barrel at a single point. The effect of the single track wear and the forced side loading is commonly noticed as a dark or black area on a single side of the plunger. The ICT probe virtually eliminates this problem by bringing the barrel into contact with the plunger.

In addition to electrical performance, accuracy and durability are crucial aspects of probe performance. Correct registration of the fixture to the target is essential for successful contact. The inherent pointing accuracy of the probe is a considerable factor in the total accuracy of the system. Poor fixture to target registration causes increased side load forces on the probe, accelerating the wear of the plunger plating at the critical barrel contact surface, causing premature spring failure, and diminishing the tip and edge life.

Contamination can take the form of flux residues and particulate matter from the board production process and environment. These contaminants work their way into the internal portion of the probe and entrenched in the plunger tip, creating an insulating effect. Once the contaminants are trapped in the probe, an abrasive grit forms. This grit wears the plunger and barrel platings, and also accelerates spring failure. The probe then suffers from the inconsistently high resistance values seen during test.

The Titanium Pro Advantage
The Titanium Pro ICT Series features an improved plunger design and a corresponding new beam design. During the manufacturing process, the bifurcated beams are customized for each plunger, eliminating any manufacturing tolerance between the plunger outside diameter and the inside diameter of the beams. In the new design, the retained length of the plunger is reduced by .100 (2,54), allowing for a longer spring. Thus, higher forces are obtainable while eliminating the tendency for premature mechanical failure, specifically when over stroking occurs.

The ICT series features our new G2 proprietary barrel material and plating. Our G2 barrel was designed to increase the friction force between the inside of the receptacle and the outside of the barrel. In essence, it has a “less slick” fit. As a result, the Ti-Pro Series probes are less likely to “walk out” during test. To further reduce probe walk out, IDI receptacles also feature four detents as compared to others' single detent design. In testing, the Ti-Pro Probes with G2 barrels had an extraction force 25% greater than probes manufactured with an unplated surface on the outside of the barrel.

These new design features make the Ti-Pro Series by far the most robust in-circuit test probe. The compliant fit between the plunger and barrel and the gentle wiping of the plunger shaft during deflection vastly reduce wear commonly seen as a black surface on the shaft of the plunger, resulting in longer probe life. The longer spring volume, corresponding lower spring forces, and absence of grit in the internal portion of the probe all contribute to increasing mechanical spring life.

The redesigned beams, the new plunger design, the longer spring volume, the G2 barrel and the increased hardness in steel plungers, when added to the benefits of the original ICT (improved pointing accuracy, low resistance and most consistent resistance) make the Titanium Pro ICT Series Probes the total solution to In-Circuit Test.

ICT Design Features
The ICT design is the first fundamental new probe technology that addresses the three primary aspects of performance important for In-Circuit Testing: electrical resistance, pointing accuracy, and durability.

The ICT design features a process that machines the barrel top into four bifurcated beams of precise length and profile. The beams are then coined to perfect center by a special manufacturing process. This provides a compliant pressure fit against the plunger, resulting in a zero working clearance between the plunger and barrel. This seemingly simple innovation, adapted and refined from proven pin and socket connection technology, is exceedingly effective at providing substantial performance gains.

In contrast to the single and highly variable contact point in a bias design, the bifurcated beams provide full radial contact to the plunger. This enlarged contact area never changes as the probe is compressed, always occurring at the point the plunger meets the barrel beams which results in the lowest, most consistent resistance of any probe.

Additionally, the four bifurcated beams are coined to perfect center, positioning the plunger in axial and radial alignment with the barrel, as compared to bias designs that force the plunger off axis for electrical performance. The zero clearance between the plunger and barrel provides a self-centering of the plunger in the barrel, resulting in the best pointing accuracy of any probe. The zero clearance also closes the pathway for contamination to enter the internal portion of the probe dramatically impacting the longevity of the electrical performance and the probes' durability in contaminated environments.

During compression, there is a light wiping force between the barrel and plunger. This wiping keeps contamination from entering the internal area of the probe, further prolong probe life. The ICT probes have a distinct feel when compressed. Compress one between your fingers. The friction you sense during deflection of the probe is normal and expected. It is your assurance that the probe is indeed providing the pointing accuracy and consistently low resistance we promise.