A low void ratio lead-free tin paste for micro-pitch packaging and a preparation method thereof
By combining Sn-Ag-Cu-Ni-Ge alloy solder powder and non-traditional organic acid segmented activators, the problem of high void ratio in solder joints in micro-pitch packaging is solved, achieving high reliability and improved thermal conductivity of solder joints, making it suitable for high-density interconnect packaging.
Patent Information
- Application Number
- CN202610841319.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-11
- Publication Date
- 2026-07-17
AI Technical Summary
Existing lead-free solder pastes in micro-pitch packaging suffer from problems such as hindered flux evaporation, uneven solder spreading, and uncontrolled interface reactions, resulting in high void rates in solder joints and affecting the mechanical reliability and thermal conductivity of the solder joints.
By using Sn-Ag-Cu-Ni-Ge alloy solder powder and a combination of non-traditional organic acid segmented activators, the flux is activated through stepwise thermal decomposition characteristics. Combined with composite additives, a multi-level protective layer is constructed to ensure gas escape and oxide layer control, resulting in dense solder joints.
Significantly reduces solder joint void rate, improves long-term mechanical reliability and thermal conductivity of solder joints, ensures printing consistency and storage stability, and is suitable for high-density interconnect packages with pitch of 0.4mm and below.