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Low Temperature Curing SMT-Adhesive
Heraeus recently introduced a new thermosetting polymer SMT adhesive, which is designed for curing at low temperatures, e.g. 90 °C for 3 minutes (peak time). Other particular features are: ultra-high-speed dispensing with standard equipment; very wide processing window, no tendency to string, capability for very low Z-height return.
PD 977 is a single-component, solvent-free, epoxy based adhesive developed especially for the surface mounting of SMT components on to PCBs and for use on bare substrates. Trials with fastest machines on the market have been successfully completed with no stringing phenomena observed. Tests were performed both on Overhead Pressure systems and on Archimedes Screw technology
The remarkable feature of PD 977 is fast curing at low temperatures. The curing temperature depends on the curing time, and should be between 80 and 120 °C with 90°C / 3 minutes being the optimum. In laboratory tests, adhesion was sufficient even when cured at 80°C for 1 minute. However, the standard deviation of adhesion values with this profile was considerably higher. Therefore Heraeus recommends curing at 90°C/3 min.
The adhesive can easily be removed before curing with a variety of water and solvent based cleaning mediums. Due to a residual thermoplasticity, the replacement of defective components by spot heating is possible. The well-studied formulation, and many years of experience in the production of SMT adhesive, guarantee constant batch-to-batch quality.
PD 977 is available in a large number of syringes for different dispensing machines.
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Phone: +49 (0) 61 81 / 35-52 65 · Fax: +49 (0) 61 81 / 35-78 60
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