Integrated circuit (IC) testing apparatuses aimed at Kelvin contact testing typically use cantilever type contact, where one of the contacts is formed as a cantilever, and part assembly types, where both contacts are assembled over an electrical insulator. With both these types, there is a long wiping action on the pad/lead of the chip. With the part assembly type, the width of the housing partition wall is very thin, thus making it structurally weak and prone to breakage. Also with the part assembly type, accumulated tolerances are high, making assembly for fine pitching difficult.
With the ever smaller contact pads of the latest IC chips, such as wettable flank and dimple pads, Kelvin contact type testing is getting more challenging. One of the biggest problems is the tolerances accumulated throughout the testing apparatus using today's manufacturing methods. Manufacturing processes that involve contact based (cutting tool) processing often lead to accumulated tolerances that are the sum of the machine capability, method, tooling etc. Upper and lower tolerances on the component level create stack up issues that influence the final assembly. End result is a large overall tolerance that can lead to various test failures that result in more downtime.
What is needed is an improved IC chip testing solution that overcomes the above problems for a Kelvin testing solution as well as for multi-row chip testing.