Cleaning and BGA Reballing

Cleaning and BGA Reballing

After the reworking of components, especially high speed BGAs and CSPs, it is important to maintain a level of cleanliness post processing. BEST has the capability to either assure or document a given level of device cleanliness if your specifications demand this.
The Omega Meter, Ionograph, and ZeroIon are used by a number of assemblers for quality assurance purposes. These instruments compare the conductivity of the extract solution before and after testing. The "result" of this testing is reported as a sodium chloride (NaCl) equivalent per unit area.

Ion Chromatography (IC) is a tool that can be used for precision testing and process base lining. This test system can quantify and identify specific ionic species that are present on an electronic device. The most common test method is the IPC TM-650 2.3.28. The device is placed into an ionically-clean bag and is immersed in an extract solution of 75% alcohol and 25% deionized water at 80�C for one hour. This is a much more rigorous extraction method than the methods used by automated ROSE equipment. The IC then separates and detects each individual ion for which it was calibrated. Typical systems detect and measure fluoride (F-), chloride (Cl-), bromide (Br-), nitrate (NO3-) nitrite (NO2-), phosphate (PO4-), sulfate (SO42-), and weak organic acids (WOAs). Results are reported in �g/in2.