Test socket in back-end chip testing

In the microchip manufacturing process it is important to test the chips under various conditions to ensure specific functionalities as well as durability. Different test sockets are used to test numerous microchips, as specified by integrated circuit designers. As several types of high-performance and engineering plastics are used to manufacture test sockets, the demand for plastic materials continues to grow rapidly.

The same basic properties need to be provided by all variations of test sockets. These include high dimensional stability over a wide temperature range, good machinability with minimal burr formation and good mechanical strength and stiffness. These properties are important because the test sockets have to pass various tests, and at the same time be resistant and durable during various cycling tests. Furthermore, the choice of material for IC test socket applications is based on operating temperature, electrical properties, and accordingly relative cost.

In the field of test sockets we particularly recommend:

• TECAPEEK CMF
• TECAPEI natural
• TECASINT

Choose TECAPEEK CMF as a slightly more cost-effective option than polyimides. It is especially suitable for those applications that require the excellent dimensional stability characteristics that are often associated with the machining of very fine hole and pitch diameters common in micro-fabrication, combined with a need for high temperature resistance. TECAPEEK CMF has good abrasion resistance and ductility, which allows the tolerances to be maintained after 100,000 chip insertions.

TECAPEI is an excellent lower-cost choice when ESD properties are of no concern and temperature requirements are only moderately high. It also offers consistent properties and dimensional stability over a range of temperatures as those temperatures change. It should not be used in situations that require the drilling of microscopic holes. TECAPEI GF30 is a refined version of TECAPEI, which includes 30 % glass-reinforced polyetherimide. It provides greater rigidity and improved dimensional stability while maintaining many of the useful characteristics of unfilled PEI.

The highest-cost alternative, TECASINT polyimides, also offer the highest performance. TECASINT is the ideal choice for the most challenging high-temperature applications.  We can provide this polyimide-based material either with or without ESD properties.

All of the materials listed offer excellent machinability with extremely low burring. It is therefore possible to produce test sockets with tight tolerances. Using TECAPEEK CMF and TECAPEI the service life of test sockets can be improved significantly, and the materials are easy to machine.