Alpha counting for packaging materials
Read our Alpha Counting Case Study.
iRoC Technologies Alpha Counting Test Services
offer accurate alpha particle emission counting of any type of
material
involved in a chip:
- Die
- Finished packaging
- Glues and resins (underfill, molding compound)
- Solder bumps
Paste, pelletes, powder, liquids, balls, wafers (up to 300mm) or even finished packages or products can be measured. iRoC Technologies partners with Alpha Science ( Milpitas, California ) to bring the industry decades of experience in the field and including the most used detectors (proportional gas type) in the world.
The value proposition is to provide the industry with accurate data in the decision process of wether to invest in ultra low alpha materials for their devices or not. This investment which can be significant is not always necessary to keep a low level of failure in time (FIT). The value proposition is also to have a third party measure the alpha emission to complement and confirm the data given by 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 meaningless data.
An accurate knowledge of the source of alpha hitting the die is important for the calculation of FIT rate. The geometry of the packaging is also an element to take into consideration, as well as any layer of material which the particles pass through before depositing charges in the sensitive volume of the transistor. iRoC offers its customers to take all these parameters into consideration.
The typical duration of an alpha counting test with the detector is 2 to 3 days. According to the configuration of the sample, test can be either started immediately or few days are necessary for the sample preparation. The accuracy of the test is directly correlated to the duration of the test. We typically achieve ultra low alpha measurement.
The reporting to the customer comes within a few days of the end of the measurement. The report gives the alpha particles emission number and accuracy, and shows the history of the counts per hour during the test, showing the stabilization of the measurements after a first period of decay of radon and other impurities brought into the detector by the sample or just by opening its door.
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iRoC Technologies entered in a agreement with Alpha Science in 2007 under the following terms: The customer interface for the measurement of samples as well as the calibration of Alpha Science detectors and purchase of new detectors will be performed by iRoC Technologies. Alpha Science will provide the same level of technical expertise and quality of measurement for both iRoC customers and Alpha Sciences direct customers. Customer in Europe will have the benefit to use the counting service set up in iRoC’s Grenoble (France) labs. For North American customers, the counting setup in California will be used. This allow a capability for ramp up with the demand.