School is back in session and the subject in this video is low viscosity. Dr. B explains various applications that benefit from adhesive systems with a flowable consistency such as flip chip encapsulation and porosity sealing.




Video Transcript

Sam: Good morning Dr. B. We’ve been getting a lot of inquiries for adhesive bonding in which viscosity is the key criteria in the selection process. Can we review some of them now?

Dr. B: Sure Sam. What do you have?

Sam: The first call is from an electronic manufacturing company about a flip chip encapsulation. They need to fill the gap between the chip, solder balls, and the circuit board. Based on the geometry of the gaps, along with the configuration of the parts, I think a product with low viscosity offering good flow characteristics, might be useful. What would you recommend?

Dr. B: I agree with you. For such applications, dispensing needs to occur from the edge of the chip for most effective flow. That’s why low viscosity and surface wetting ability of the compound are essential for protecting the space between the die, substrate and interconnect bumps.

Sam: Would you recommend a one- or two-component system?

Dr. B: Either one might work well depending on thermal stability of the substrates. If heat curing is possible, the addition of heat can also help facilitate flow properties even further.

Sam: We also got a call from one of our current customers. They’re in need of a compound for a porosity sealing application. What do you suggest?

Dr. B: What are the details of their application?

Sam: They are sealing steel parts that require protection against water, oils and high pressure. We usually recommend one part epoxy systems for impregnation. Do you think that a low viscosity two component epoxy would be suitable for porosity sealing as well?

Dr. B: Yes, two part systems with extremely low viscosity and long working life are available for such applications. However, one component heat curing epoxies offer many advantages as they require no mixing and have unlimited pot life at room temperature. For efficient void filling of microporosity, the substrates can be dropped in a tank for vacuum impregnation.

Sam: Wow, Dr. B! That’s some great insight! Now I can recommend the most suitable one part system for their application!

Low viscosity compounds can be formulated to exhibit different cure speeds, working life and performance properties.