Tool/software:
Hello Customer Service,
This message is in regard to Ti components sourced from Ti direct and authorized channels using the roughened leadframes.
With regard to the roughened leadframed parts, we have noticed a consistent discoloration of the leads that were not present in any regularity with Ti components previously sourced with non-rough leadframes.
When this discoloration issue was presented to Ti Support to obtain an explanation, Ti sent over a document entitled "Application Note Single Side Rough Leadframe" as their response. In this document, Ti explains the differences between the rough leadframe technology and the previously used non-rough leadframe technology. According to this document, both leadframes use a base copper and nickel, palladium, gold alloy finish.
With the composition of the leadframe alloys used being identical, an explanation is given in the document that rough leadframes cause a darker appearance due to the non-uniform/uneven dispersion of light rays that come into contact with the roughened surface.
Classic's Quality Team is aware of the darkening effect and the result of that effect is not the issue that is in question.
We have detected, with regularity, a discolored layer on the roughened leadframes which can be removed using various techniques chemical and mechanical. This discolored layer is what's causing our Quality Team and our customer's quality teams concern.
Upon further research, we were able to obtain an article written by the "International Research Journal of Advanced Engineering and Science" which is entitled, "Copper Migration Induces Discoloration on a NiPdAu Surface". In this article, the information provided and the sample photos seem to match the issues we are seeing with the roughened leadframe parts.
As such, it is Classic's belief that we are seeing copper migration and subsequent oxidation on the leads of the parts we're receiving from Ti with roughened leadframes.
Due to these parts being purchased direct from Ti and authorized sources only, we're confident that the parts have not been mishandled or exposed to the environment in a way that is inconsistent with Ti's recommended storage protocols.
Due to the copper migration and oxidation being consistently found on roughened leadframed parts only, we believe that the roughened surface is prone to accumulating more ionic contaminants, or in other ways fostering a surface that is far more susceptible to copper migration and oxidation than the non-rough leadframed parts.
We ask Ti Support to evaluate our presented findings and provide us with more information so that we can alleviate the concerns reported by our customers.
Our customer's are concerned that the discolored oxidized layer will potentially cause problems with the soldering and performance of the part.
Here is the link to the article: http://irjaes.com/wp-content/uploads/2020/10/IRJAES-V4N2P419Y19.pdf
Thank you in advance for your support.
