Alpha Counting

All materials within direct proximity of the die have the potential to create failures in the chip.

These failures are due to the decay of radioactive elements that can be found in those materials, sporadically emitting alpha particles with energies sufficient enough to travel
through several tens of micrometers and to create upset. The integration of latest process technologies and a wider usage of flip chip package makes this issue more critical as before. As a consequence, Ultra Low Alpha(ULA) materials are in growing demand for use in the manufacturing and packaging of the latest semiconductor chip technologies.

We provide alpha counting service through our partnership with Alpha Scicences, the manufacturer of one of the most widely adopted ultra low backgroun alpha particles counter in the industry. The goal of this service is to provide the industry with unbiased, accurate measurement data to help in the decision process of wether to invest in ultra low alpha materials for their devices or not. As a third party expert, we complement and confirm the alpha emission data given provided the material manufacturer.

Running accelerated alpha particles test is not enough for an accurate FIT rate assessment. This gives only the cross section, or sensitivity of the die. Many engineers just assume the average alpha emission of the package be 0.01 alpha/cm2/hr, and derive the FIT rate from there.

This approach is highly inaccurate because it does not represent the reality of the alpha particles field generated by the packaging and can yield to unacurate reults.

The geometry of the packaging is also an element to take into consideration, as well as any layer of material which the particles travel through before depositing charges in the sensitive volume of the transistor.

IROC offers its customers to take all these parameters into consideration.

IROC Alpha Counting Test Services offer accurate alpha particle counting of any type of material involved in a chip:

  • Solder paste
  • Finished packaging
  • Underfill, molding compound
  • Solder bumps
  • wafers (up to 300mm)