Part Number: TMUX4827
Dear TI Team,
We are using the TMUX4827YBHR in a fine-pitch analog application intended for long operational life (>10 years).
As per the datasheet, the recommended PCB pad width is 0.23 mm, with solder mask opening equal to pad size or up to +0.05 mm.
Since this device has a fine pitch package and is intended for long-term field usage (10+ years), we performed a reliability review focusing on potential tin whisker growth risks, especially considering lead-free assembly and long operational life.
As a precautionary design measure, we optimized the PCB pad width from 0.23 mm to 0.20 mm (approximately 13% reduction in exposed copper area). This change remains within IPC land pattern tolerance guidance (variation allowance up to ~20%).
Before releasing the layout for fabrication, we request clarification on the following:
- Is 0.20 mm pad width acceptable from functionality and reliability standpoint?
- Could reducing the pad width from 0.23 mm to 0.20 mm negatively impact solderability or assembly yield?
- Are there any internal TI assembly qualification margins built into the recommended 0.23 mm pad size?
- Does TI have specific guidance for high reliability / long-life (>10 years) applications regarding pad design optimization?
This product is intended for long-life deployment; therefore, PCB land pattern decisions must align with component qualification and reliability expectations.
We request TI’s formal technical confirmation that reducing the PCB pad width from 0.23 mm to 0.20 mm does not invalidate TI’s assembly qualification margins, reliability characterization, or recommended manufacturing guidelines.
If strict adherence to the datasheet land pattern is required to remain within TI’s validated conditions, please explicitly advise so that we can revert prior to layout release.
PFA of datasheet below
Best Regards,
Sadhana K V
