Polymer Material
Die attach and underfill material composed of non-conductive polymer resin provides structural reinforcement and environmental protection beneath semiconductor dies. Formulated non-conductive paste encapsulates flip-chip interconnects or fills spaces between die pads and substrates during component assembly. The polymer mixture governs mechanical strain distribution across micro-bump arrays and protects sensitive silicon faces.
The material stops functioning when processing temperatures exceed thermal decomposition thresholds or when cure state remains incomplete.
Joint Protection
Thermal expansion mismatch between silicon dies and organic carriers places severe shear stress on micro-scale solder joints. Pre-applied non-conductive paste flows around solder bumps during thermal compression bonding, hardening into a solid epoxy matrix. The cured resin distributes thermal strain across the full die surface, extending solder fatigue life.
Mechanical anchoring prevents interconnect cracking during drop impact and thermal cycling.
Rheology Control
Viscosity measurement using rotational rheometers establishes flow characteristics before application. Precision dispensing systems enforce volume accuracy across substrate array sites. Material specifications dictate target filler particle size distributions to prevent nozzle clogging during automated dispensing.
Automated inspection verifies dot diameter and placement accuracy on receiving substrates.
Void Formation
Moisture absorption in uncured paste causes outgassing during thermal compression bonding. Trapped volatiles generate voids within the cured matrix, reducing mechanical strength and introducing localized hot spots. Moisture exposure during storage destabilizes the resin matrix, shortening shelf life.
Improper storage temperatures cause pre-gelation, which prevents complete joint encapsulation.
