Design and Process Considerations in Transitioning To Aluminum Ribbon

摘要

Bonding of power devices is experiencing a rapid transition to aluminum ribbon for many reasons. Better electrical characteristics,improved heat dissipation,fewer bonds,and improved reliability are some of the most obvious advantages. The huge increase in battery powered motors that require more powerful devices in smaller packages also increases the need for ribbon bonding. SPM has developed SPM POWER BOND RIBBON~TM,a high purity corrosion resistant aluminum bonding ribbon,to meet this demand. New improved spooling is now available for ribbons as large as .080 X .010,and as small as .030 X .003 mil. This spooling method decreases or eliminates most of the traditional issues with despooling of bonding ribbons and is compatible with the most commonly used bonding machines. Several Bonder Manufacturers have introduced new equipment to handle the conversion to heavy aluminum ribbon. Design consideration must be given to items such as bond pad design,loop heights,bonding angles and more. A key point to consider is that fact that one bond of a given size Bonding Ribbon can replace several wire bonds. For example: one bond of .060 X .008 ribbon can replace 6 wires of .010 diameter. This is key to increasing throughput and reliability and ultimately reducing costs. This paper will address the basic design characteristics that need to be considered in order to take advantage of this emerging technology.