KYOCERA advanced ceramics for the semiconductor industry

There is currently more than enough demand to justify the expansion of semiconductor production in Europe. As a result, continuous progress is also being made on the development front. The structures of these highly integrated circuits are becoming smaller and more compact every year. The production of AI chips and components for fifth-generation electronic devices, such as 5G smartphones, is particularly demanding. Accordingly, the quality and functional testing of these advanced microchips is equally complex.

The key material: silicon nitride

Before the chips are separated further, they are tested on the silicon wafer. What are known as ‘probe cards’ guide up to 100,000 fine contact needles and more to the contacts of the microchips, making it possible to test their functionality. A silicon nitride plate is used to guide and insulate the contact pins from each other in the probe card. This fixes the needles at regular intervals of a few tens of micrometres.

Silicon nitride is able to keep these small distances absolutely constant even over the extreme temperature range of between -40 and +200 °C (degrees Celsius) at which the tests are carried out.

The coefficient of thermal expansion of the new material has been specifically increased in comparison to Starceram N3000 P (comparison temperature of +150 °C):

Starceram N3000 P                           Newly developed material

a=2.2× 10^(-6)× K^(-1)        -->            a=4.4× 10^(-6)× K^(-1)

In addition to the increased coefficient of thermal expansion, the new silicon nitride also has a high flexural strength of > 800 MPa (megapascals). This allows the production of thin silicon nitride plates with very narrow distances between the contact needles. These are important properties, especially when it comes to testing next-generation microchips.