Low-Temp Solders Are Suddenly Critical For Chiplets And Photonics


Key Takeaways: Tin-bismuth-based solders enable reduced warpage and compatibility with silicon photonics and other temperature-sensitive components. A novel soldering process using white light could help prevent cracks in flip-chip BGA package solder balls, while reducing the carbon footprint. Hypoeutectic Sn-Bi based solders prove especially promising as an SAC305 replacement. ... » read more

Challenges Grow For Creating Smaller Bumps For Flip Chips


New bump structures are being developed to enable higher interconnect densities in flip-chip packaging, but they are complex, expensive, and increasingly difficult to manufacture. For products with high pin counts, flip-chip [1] packages have long been a popular choice because they utilize the whole die area for interconnect. The technology has been in use since the 1970s, starting with IBM�... » read more

Bump Reliability is Challenged By Latent Defects


Thermal stress is a well-known problem in advanced packaging, along with the challenges of mechanical stress. Both are exacerbated by heterogenous integration, which often requires mingling materials with incompatible coefficients of thermal expansion (CTE). Effects are already showing up and will likely only get worse as package densities increase beyond 1,000 bumps per chip. “You comb... » read more