COMPONENT SOLDERABILITY TEST/CRITERIA EVALUATION

摘要

As we move out of water soluble halogen activated fluxes into the era of no-clean fluxes, component solderability will become a key part of our success or failure. This migration can typically result in a process which is much less robust and much more affected by the properties of incoming materials such as solderability. To further complicate the issue, there is much disagreement in industry as to what exactly constitutes good solderability and how exactly to evaluate it.rnIBM Charlotte is presently evaluating no-clean pin-through-hole (PTH) and surface mount technology (SMT) processing and, therefore, is in the midst of this dilemma. Solderability problems, except in extreme cases, have typically been hidden by the use of highly activated water soluble fluxes. This is not the case with no-clean fluxes.rnThe purpose of this paper is two-fold. First to show a present snapshot of incoming component solderability, and secondly, attempt to compare two of the more common solderability test methods; namely the older 'Dip and Look' method and the newer Wetting Balance method as described in IPC ANSI/J-STD-002. Testing was performed on sixteen PTH components which were suspected of having poor solderability during initial stages of the no-clean conversion. As specified in the IPC document, type R flux was used as the test flux on components exhibiting Category 1 (as-received) and Category 3 (steam-aged) conditioning so as to determine their present and future solderability. In addition, the tests were also performed using a standard activated water soluble flux as well as three candidate no-clean fluxes on Category 3 components. Category explanations can be found in Section 1.4 Coaling Durability of the IPC document.