July 27, 2006 Carlsbad, CA -- Palomar Technologies has introduced the new Model 3500-III automatic die bonder. Designed for fully automatic, high-accuracy, precision microelectronics assembly, the computer-controlled work cell performs adhesive dispense, component placement, die attach, and flip-chip operations over a 720-square-inch (0.46-square-meter) work area. Applications include flip chip, stacked die, chip-on-board, fine pitch SMT, MEMS devices, multichip modules, microwave modules, optoelectronic modules, and hybrid microcircuits.
The 3500-III is capable of performing automated eutectic die attach using backside metalized die or preforms, and enables bonding of thin die with air bridges using two- or four-sided perimeter collets. Palomar's patented eutectic process is key for high yield and reliability, the company says, because eutectic die attach is one of the most difficult processes to control. Palomar's pulse heat process controls the heat throughout the entire process from temperature ramp up to cool-down.
Using look-up and look-down cameras for flip-chip applications and relative-to referencing for linear micro-strip line placement, the 3500-III's sub-micron axis resolution yields typical placement repeatability of better than ±12 micron (0.5 mil), 3 sigma with fluids and ±5 micron (0.2 mil), 3 sigma with pulse heat eutectic applications.
With the 3500-III, placement of the die in relation to a previously placed die can also be tightly controlled through custom automation algorithms. Relative-to-die placement algorithms place the die so that the second, third, and each die or substrate thereafter is placed relative to the final location of the last placed component rather than the package. This provides greater accuracy from component to component. It also controls the subsequent wire length and position, ensuring that the wires are parallel and the lengths are the same, factors important for high frequency electrical performance.
The machine base is a honeycomb core optical table that provides vibration damping and thermal settling response that Palomar asserts is superior to granite. Its work area is the largest available, the company adds. The cantilever design permits unobstructed, open access on three sides for set-up. Soft touchdown or non-contact laser height sensing mechanisms assist in precise pickup and placement of fragile devices such as gallium arsenide. An eight-position turret head can rapidly change tools on the fly without a space and time-consuming tool dock assembly. Because it is constructed from an optical breadboard where parts can be bolted down in a myriad of configurations, any form of presentation such as expanded wafers, waffle or gel packs, tubes, or tape and reel may be used and options for up to three dispensers, hot rails, heat cure stations, hot gas, UV fluid curing systems, and more can be incorporated.
The 3500-III employs an infrared light curtain around the entire open perimeter of the assembly cell. This safety curtain sends an infrared signature down each inch of the perimeter so that it cannot be fooled by background thermal radiation. When the system is in operation and the safety curtain is violated, the system immediately (within ~ 3 msec) shorts the inputs to the digital servo driven motors, bringing all motion to a near instant stop.
The system uses a Windows XP operating system, employing Cognex Corp.'s latest Series 8000 gray-scale pattern recognition systems.
Owners of the Model 3500-II Automatic Component Placement Systems can order a 3500-III upgrade directly from Palomar.