China PCBA factory Underfill of Eternity EMS What is Underfill? Underfill is an epoxy material that fills gaps between a chip and its carrier or a finished package and the PCB substrate. Underfill protects electronic products from shock, drop, and vibration and reduces the strain on fragile solder connections caused by the difference in thermal expansion between the silicon chip and carrier (two unlike materials). In capillary underfill applications, a precise volume of underfill material is dispensed along the side of a chip or package to flow underneath through capillary action, filling air gaps around solder balls that connect chip packages to the PCB or stacked chips in multi-chip packages. No-flow underfill materials, sometimes used for underfilling, are deposited on the substrate before a chip or package is attached and reflowed. Molded underfill is another approach that involves using resin to fill gaps between the chip and substrate. Without underfill, the life expectancy of a product would be significantly reduced due to the cracking of interconnects. The underfill encapsulation provides the following benefits to a flip chip assembly. 1. It provides mechanical protection by enhancing the mechanical bonding between the dies or die and distributes any mechanical stress throughout the assembly protecting the conductive balls/bumps. 2. It provides thermal protection by improving heat transfer from the dies to the substrate and provides better heat distribution relieving the conductive bumps/balls of thermal stress. 3. It also relieves mechanical stress from the bumps/balls caused by thermal expansion mismatch. 4. Overall it improves the function, reliability and durability of the flip chip assemblies. Brief Introduction of Eternity EMS: Established in 2005, We are an Electronics Manufacturing Services (EMS) Provider in China offering services from joint design, engineering and prototyping services to new product introduction (NPI) services and mass production. Besides, Eternity EMS can provide raw materials selection and procurement, quality control, logistic and delivery and after-sale services to our customers in respect of our assembling and production of Printed Circuit Board Assembly and fully-assembled electronic products. After 16 years' development, 1300 Eternity people in three production plants have confidence to provide professional electronics manufacturing services to OEMs and brands all the world. Eternity accumulates manufacturing knowledge by cooperation with global leading brands, and we stay focus in the fields as communication and telecom, financial device, industrial equipment, new energy, automotive, and medical electronics. We provide PCBA and Box Build for SAMSUNG, for ABB, for BYD etc., the cooperation with leading brands not only make Eternity build integrated system like ISO9001, ISO14001, ISO45001, ISO13485, ISO16949; but also motivate Eternity to keep investing in the latest technology and equipment. In one world, we are your R & D partner, your production provider, your supplier manager, and your after-sale supporter.China PCBA factory website:http://www.eternityem.com/pcba/