MSL Level 3 Microcontroller Components where pin 1 indicator (triangle on the bottom PCB) was observed with oxidation (see oxidation).
Welcome to the Forum! We are researching this and will get back to you soon with the answer to your question.
Hello again Mjiang - can you please share who the manufacturer is and the part number of the MCU you are asking about. The affect of oxidation on a part may vary from manufacturer to manufacturer, so it would be helpful if you can share that information.
That pin 1 indicator is not a “pin”, so that point, specifically, won’t affect solderability. What matters is the condition of the solder balls. It’s hard to say what condition they are in, based on the images. It does not look like that indicator has any sort of plating, so it would likely be much more sensitive to moisture than the solder balls.
Was the part removed from the moisture barrier packaging for some period of time? Digi-Key parts are stored in a humidity and temperature controlled environment and all parts are sealed with desiccant in moisture-proof packaging, so they should not have had the opportunity to be exposed to significant moisture here.
I hate to ask the obvious, but was this part even purchased from us? do you have the part number and invoice number?