Palomar Technologies Introduces the Gold Connection for Gold Ball Bump and Flip Chip Thermocompression Bonding.

Business Editors and High-Tech Writers

Palomar Technologies, the leading manufacturer of automated high-precision assembly systems for broadband communications, introduces Palomar's Gold Connection(TM), consisting of Palomar's new Gold Bumper(TM) and Flip Chip TCB(TM) (Thermocompression Bonder).

The Gold Connection is an integrated solution that addresses the industry's growing need for smaller package density, increased reliability, and increased signal performance, while providing a clean, environmentally safe alternative to lead-based processes.

The Gold Bumper produces gold wire ball bumps for flip chip applications. Using standard 1 mil gold wire in a process similar to wire bonding, the Gold Bumper creates planarized, tailless bumps in a consistent, repeatable, single-step process with up to 5-micron placement accuracy. Planarity and a consistent top surface area on each bump provide ideal connectivity and attachment for flip chip applications.

Palomar's Gold Bumper provides the flexibility to quickly and easily change the ball array, position, and bump shape to match the desired attach process. Because of the Gold Bumper's unique tool motion capabilities that can shear the top of the bump without leaving a tail, a flat top can be obtained without the need for a separate coining machine or process, saving process time and cost. Gold bumping is a solderless, dry, clean process that doesn't require reflow and can be used for small or large volume production.

Based on Palomar's Continuous Bonding Technology(R), the Gold Bumper creates a variety of bump shapes in an in-house, rather than a foundry or fab, process. The Bumper's 12 x 6 inch (300 x 150mm) platform bumps singulated die or entire wafers (up to 300mm) to accommodate small runs for R&D and prototyping, batch runs, and contract or high volume manufacturers.

Said Palomar product marketing manager Jerry Jordan, "Gold bumping provides superior electrical connectivity, low inductance values, reduced electrical loss, and lower power requirements, making it attractive for those seeking a seamless migration path from gold wire bonding."

In view of the increased demand for lead-free interconnect solutions, gold bumping is an excellent alternative to solder bumping. Gold bump connections offer a cleaner process and eliminate the need for under-bump metallization (UBM) and fluxing. Because gold bump formation is a variation on the 50-year old wire bonding process, the reliability of these bump connections is well established and documented.

Palomar's Flip Chip Thermocompression Bonder (TCB) for flip chip and die attach of gold wire ball bumps is the companion to the Palomar Gold Bumper. The bonder's 700 sq. in. (17780 mm2) work area is suited for prototyping, small runs, or volume production. Based on Palomar's proven 3500-II die bonder technology, the Flip Chip TCB provides a lead-free process that doesn't require additional off-line processes to complete the die connection to the substrate it is mounted on. The metal-to-metal process provides increased strength and electrical conductivity of the bond. It is accurate and repeatable to +5 microns. The flipping mechanism can flip die 90 or 180 degrees depending on the application.

Flip Chip is basically a three-step process: bump, flip, and attach. The first step involves the placement of gold bumps on a single die or die on a wafer (first metallic bond). This is performed by the Gold Bumper. The second and third steps, performed by the Flip Chip TCB, flip the die so that the bumps are facing the substrate, and then accurately attach (second metallic bond) the die to a substrate or package.

In thermocompression bonding, heat and force are applied to the die in order to form the second metallic bond. The force "sandwiching" the bumps between the die and the package causes the two metallic bonds (top and bottom of the ball bumps) to be nearly identical metal-to-metal connections that contribute to the high-speed electrical performance of the package. This attachment method can be used either by itself or in conjunction with adhesives such as conductive epoxy or non-conductive underfills. The gold-to-gold contact of a gold bump adhered with thermocompression bonding provides ten times more electrical connectivity than if solder were used. When gold bumps and thermocompression bonding are used on silicon chips, they eliminate the need for under bump metallization that is required for solder.

About Palomar Technologies

Palomar Technologies provides complete process and equipment solutions for precision automated assembly of optical, RF and microelectronic packages in the photonic, wireless, microwave, automotive, aerospace, and medical industries. Processes include high accuracy component assembly with eutectic solder or epoxy, precision ball bonding, and wedge bonding for fine pitch devices. Equipment solutions range from islands of automation to complete integrated assembly lines of dispensers, placement stations, ovens, cleaners, and wire bonders with automatic handling between process stations. Palomar Technologies won the 2001 Advanced Packaging Award, Fiberoptic Product News 2001 Technology Award, and the Microwaves & RF Top Products of 2001 award for its innovative products and technology. For more information, visit www.palomartechnologies.com or call 760/931-3600. Palomar Technologies, "Enabling Lightwave Connectivity."