assembly cleanliness and ionic testing| 13 February, 2009
Many shops require levels for typical component packages on FR-4 or a like substrate to be 2, 9, 15, 1 and 10 mg/in2 for fluoride, chloride, bromide, nitrate, and sulfate respectively. These levels can change for Medical or Automotive.
assembly cleanliness and ionic testing| 14 February, 2009
We believe that it's perfectly resonable for you to define the cleanliness that you require. We recommend that you leave it at that and not define the process or materials that your supplier use in meeting that cleanliness level.
Start with a dirty board, end-up with a dirty assembly.