Here is the abstract you requested from the IMAPS_2013 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Better, Faster and Cheaper Precision Cleaning: Advanced CO2 Cleaning Technology|
|Keywords: Precision Cleaning, CO2 Technology, Contamination Control|
|Precision cleaning of microelectronic substrates is a requirement prior to critical fabrication steps such as wire bonding and adhesive bonding, and following processes such as laser machining and soldering. With respect to adhesive bonding, difficult-to-bond materials such as thermoplastics, metals, glasses, ceramics and composites of same present special challenges. Important surface preparation steps include surface cleaning, microscopic etching, and functionalization. This is especially true for materials which exhibit low surface energy or heterogeneous surface contamination and chemistry. Surface treatment challenges are amplified when bonding adherent surfaces with dissimilar cohesive energy densities, for example metal-to-polymer and metal-to-ceramic. Post-laser processing of organic substrates leaves carbon char and particles on or near the laser kerf and surrounding area. These residues must be removed prior to the follow-on fabrication steps such as plating, adhesive bonding, wire bonding, and precision assembly operations. In this regard, conventional precision cleaning processes typically require multiple steps, chemistries, and equipment to accomplish the decontamination and surface modification if required. Moreover, conventional cleaning methods are sometimes non-selective for both contaminant and contaminated surface. For example, conventional vacuum plasma using Ar/O2 is typically used to remove post-laser char on organic films such as Kapton flexible circuits. Vacuum plasma is usually performed off-line, taking up to 30 minutes to complete, and is generally non-selective for the organic contamination. The entire organic substrate is etched away during the cleaning process to remove laser char. In another example, surfaces are prepared for adhesive bonding using multiple steps involving vacuum plasma, organic solvents, chemical etchants or primers. Advanced carbon dioxide (CO2) cleaning technology uniquely and consistently achieves precision clean (and functional surfaces if needed), including 2D and 3D surface geometries, for a variety of critical cleaning applications using one process chemistry – CO2. Numerous possible hybrid combinations of CO2 are possible including centrifugal CO2 immersion, supercritical CO2 extraction, CO2 composite spray, and atmospheric CO2 plasma cleaning and treatment. Besides addressing a broad spectrum of surface treatment requirements, CO2 cleaning technology can adapt to existing or new manufacturing tools or processes to improve production flow, increase equipment utilization, and decrease floor space. Measurable benefits derived from utilizing this technology include more productive processes with reduced labor and material inputs, improved worker safety and environmental quality, and cleaner parts – faster and with a lower cost-per-clean.|
|David Jackson, President
Santa Clarita, CA