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Copper Bumps for Flip Chip Assembly

Traditional wire bonding used in the semiconductor manufacturing industry tends to have performance related issues that are tied to inductance and capacitance. Flip chip assembly, which is made using an entirely different structure, has resolved these issues and is able to perform at a higher level. While flip chips have been around for over five decades, companies of various industries have slowly began developing them for thousands of different applications, recently reaching the semiconductor manufacturing industry.

The semiconductor manufacturing industry has pre-built semiconductor devices called bumps onto the chips themselves. These copper bumps are then mounted onto the substrate. During this mounting process, the chip is flipped so the bumps are placed in a very specific location that will generate a strong electrical connection. While this method has successfully managed to resolve the issues of traditional wire bonding, flip chip assembly is not without its problems.

The flip chip assembly process creates a high level of mechanical stress between the chip and the substrate due to temperature changes, which create differences in thermal expansion coefficients. The constant changes in temperature throughout the semiconductor manufacturing process causes repeated expansion and contraction, which leads to damage, such as cracking, of the copper bumps along the surface of the chips.

To reduce this damage, underfilling has been designed to fill the space between the chip and the substrate, working as an adhesive to reduce expansion during this semiconductor manufacturing process. In addition to protecting the bumps, the underfill also protects the chip from moisture and other foreign matter. A number of semiconductor manufacturing companies also use taller copper semiconductor devices that reduce the amount of stress by creating a greater distance between the chip and the substrate. With taller bumps, underfill is distributed in a quicker and more consistent fashion.

Copper has a very high level of mechanical strength, which offers increased performance and connections. These copper bumps allow the semiconductor manufacturing industry to rely on the flip chip assembly process due to its increased ability to effectively manufacture semiconductor products for customers.

At Shin-Etsu MicroSi, we are always on top of the latest semiconductor manufacturing technologies to ensure that our customers are receiving the very best products and services in the business. We provide the supplies that you need to successfully manage your semiconductor and microelectronic operations. For more information on flip chip assembly or any other questions on semiconductor manufacturing products, please call Shin-Esu in Phoenix at (480) 893-8898 or contact us online.