Maskless Screen Printing Process using Solder Bump Maker (SBM) for Low-cost, Fine-pitch Solder-on-Pad (SoP) Technology
- 한국마이크로전자및패키징학회
- 마이크로전자 및 패키징학회지
- 제20권 제4호
- : KCI등재후보
- 2013.12
- 65 - 68 (4 pages)
A novel bumping process using solder bump maker (SBM) is developed for fine-pitch flip chip bonding. It features maskless screen printing process. A selective solder bumping mechanism without the mask is based on the material design of SBM. Maskless screen printing process can implement easily a fine-pitch, low-cost, and lead-free solder-on-pad (SoP) technology. Its another advantage is ternary or quaternary lead-free SoP can be formed easily. The process includes two main steps: one is the thermally activated aggregation of solder powder on the metal pads on a substrate and the other is the reflow of the deposited powder on the pads. Only a small quantity of solder powder adjacent to the pads can join the first step, so a quite uniform SoP array on the substrate can be easily obtained regardless of the pad configurations. Through this process, an SoP array on an organic substrate with a pitch of 130 μm is, successfully, formed.
1. Introduction
2. SBM and Maskless Screen Printing Process
3. Parameter Affecting Aggregation of Solder Powder on Pads on Substrate
4. Conclusions
Acknowledgements
References