Power amplifiers amplify the radio transmission of voice and data to and from wireless base stations. These components are essential to expanding wireless services and implementing new technologies, including Bluetooth and next generation 3G wireless. Because power amplifiers are the most expensive component in wireless base stations, manufacturers are looking for ways to reduce costs while meeting increasing performance requirements to support new services.
In manufacturing power amplifiers, precise placement of fragile galliumarsenide (GaAs) die is critical to the component's performance. Palomar has already significantly reduced manual labor with its automated wire bonding and die attach equipment that precisely picks and places die into its package and bonds it in place. The new HotRail RFA takes even more time out of the manufacturing process by eliminating batch processes. The full system, called an assembly cell, provides a highlyaccurate and repeatable process that meets stringent performance requirements at high volume production levels.
With the HotRail RFA, operators can load an entire shift of parts while the machine uses a sophisticated vision system to eject and attach fragile die. Pre-heat mesas, or HotRails, pre-heat the parts prior to bonding to achieve higher throughput. The HotRail clamping mechanism holds the parts in place at the optimum temperature to achieve precision side-by-side placement of die for subsequent wire bonding. Highly accurate and repeatable spacing of the die is critical so that wires connecting them to the package are the same length. This process is essential for meeting high frequency RF device impedance specifications. The HotRail RFA process control system monitors the heat, generating an alarm if temperatures exceed user-defined limits.