Ceramic ball grid array

Figure 12.9 Acoustic image of solder bumps in a ceramic ball grid array package. Comparing this image with the results of X-ray microscopy indicated that some of the solder bumps had separated from the die surface.

CBGA ceramic ball grid array NEPP NASA Electronic Parts and Pad ging... 

The solder balls for area array components (e.g., ceramic ball grid arrays—CBGAs plastic ball grid arrays—PBGAs chip scale packages—CSPs) do have, of course, a processing-related cost that will not have as much effect in blurring the cost differential between lead and lead-free solders as occurs with solder pastes. Like solder bars, the cost of solder will likely track more closely with the raw material cost. 

Farooq, M. Ray, S. Sarkhel, A. Goldsmith, C. Evaluation of lead(Pb)-free ceramic ball grid array (CBGA) wettability, microstructure and reliability. Proceedings Electronic Components and Technology Conference, Orlando, FL, May 2001 978-986. 

The failure data of area array solder joints (e.g., flip chips, ceramic ball grid arrays) are often fitted to a lognormal distribution. The choice of the distribution selected may depend on the confidence level chosen for the fit. A lognormal distribution may satisfactorily represent failure data at a lower confidence level in some cases. There are two variations for WeibuU distributions the two-parameter distribution and the three-parameter distribution. The third parameter, called the location parameter, represents the minimum time-to-failure. Sometimes the failure data exhibit a slight curvature at a lower failure probability deviating from a two-parameter Weibull distribution. A three-parameter Weibull distribution can be utilized to better fit the data. 

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