The Glue Talk Blog

Underfill for the electronics market from H.B. Fuller.

Understanding Underfill

Posted 12/13/2018 by Fei Xie, Ph.D. Senior Scientist, Microelectronics Packaging

According to the Thermal Management Market by Material Type (Adhesive, Non-Adhesive), Devices (Conduction, Convection, Advanced, Hybrid), Service (Installation & Calibration, Optimization & Post Sales), End-Use Application - Global Forecast to 2022 report, the thermal management market is expected to grow at a CAGR of 7.91 percent with a total worth of $14.24 Billion USD by 2022.

This market growth is likely due to a higher demand for smaller and lighter devices and an increased need for thermal management in consumer electronics. In the thermal cycling of electronic devices, there is relative movement between the Ball Grid Array (BGA) and Chip Scale Packages (CSPs) and the printed circuit boards (PCBs), resulting in mechanical fatigue and failure of the solder joints that electrically interconnect the chip to the board. An underfill, typically an epoxy composition, connects the chip to the board by capillary action and then is heated to cure. The underfill material provides mechanical reinforcement to the solder joints which can increase the life of the chip. This mechanical reinforcement improves dropping performance and raises the thermal cycling performance for CSP, Wafer Level Chip Scale Packages (WLCSP), and Flip Chip components by about seven to 10 times.

Flip Chip components


The use of underfill is increasing in portable devices due to:

  • Finer pitch packages.
  • POP packages.
  • Thinner main PCBs.
  • Challenging drop test requirements.
  • Larger BGA/CSPs and WLCSPs.

Underfill Diagram.

Device reliability is a critical measure of product performance in the electronics industry. High-performance underfill materials are used underneath chips, devices, or components of electronic products to improve their reliability and offer structural reinforcement of sensitive device components. Our PCB assembly materials have excellent performance and can increase productivity by matching materials to provide consistency in the manufacturing process and device performance.

H.B. Fuller underfills typically offer:

  • High reliability (drop, shock, autoclave and temperature cycle).
  • Fast flow and easy processing.
  • Rework versus reliability balance.
  • Excellent flux compatibility.

Read more about our PCB assembly and how we can partner with you to help solve all of your electronics bonding and encapsulation needs.

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