Discussion Overview
The discussion revolves around the best pad finish for a PCB designed for repeated soldering, focusing on the durability of the pads under mechanical and thermal stress. Participants explore various finishes, soldering techniques, and design considerations for a specific experimental setup involving low current measurements.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
- Mathematical reasoning
Main Points Raised
- One participant inquires whether ENIG or bare copper is better for pads that will undergo repeated soldering, suggesting that other finishes may also be considered.
- Another participant suggests using plated-through-holes (PTH) to reinforce the copper pads and mentions that solder resist can help maintain pad integrity.
- Several participants ask for clarification on the intended use of the pads, including whether they will be used for surface mount technology (SMT) or PTH components, and the sizes of the pads and components involved.
- A participant notes that increasing the thickness of the outer layer copper features could enhance pad robustness.
- One participant mentions that for mechanical loads, solder pins or rivets are commonly used, although this may not be applicable in all scenarios.
- Another participant discusses the degradation of the bond between copper and the board due to heat from repeated soldering, suggesting alternatives like bonding pigtail leads to the pads for connection changes.
- Concerns are raised about the potential damage to the board from thermal cycling and the process of removing solder, with a focus on the implications of using hot solder.
Areas of Agreement / Disagreement
Participants express various concerns and suggestions regarding pad finishes and soldering techniques, but no consensus is reached on the best approach. Multiple competing views remain on the optimal solution for the specific experimental conditions.
Contextual Notes
Participants highlight limitations related to thermal cycling, the potential for damage during solder removal, and the specific conditions under which the PCB will be used, including temperature and pressure considerations.
Who May Find This Useful
This discussion may be of interest to PCB designers, engineers working with soldering techniques, and researchers conducting experiments that involve repeated soldering on PCBs.
