Acceleration and deceleration in SMT feeders refer to the rapid changes in tape velocity that occur during each indexing cycle. Unlike continuous-motion systems, SMT feeders operate in short bursts, rapidly accelerating the tape forward and then stopping it precisely at the pickup location.
These velocity changes generate inertial forces that act on the tape, the components, and any splice joints present.
During indexing, the feeder motor applies torque to overcome tape inertia, friction, and component mass. The faster the acceleration, the higher the inertial force transmitted through the tape.
Deceleration is equally critical. When the feeder abruptly stops the tape, the inertia of the moving tape and components continues forward momentarily, creating a reverse load that stresses adhesive joints and carrier tape interfaces.
These forces are significantly higher than those observed during slow, manual tape pulling.
Acceleration-induced forces are a primary contributor to delayed splice failures. Adhesives that perform well under steady tension may gradually deform or slip when exposed to repeated inertial loading.
This is especially problematic for splice systems designed around peel strength rather than shear resistance, as inertial forces act parallel to the tape plane.
Repeated acceleration cycles can cause micro-slippage that accumulates until sudden failure occurs.
Higher placement speeds, tighter cycle times, and aggressive feeder tuning increase acceleration forces. Partial reels and short tape lengths amplify these effects because there is less mass downstream to dampen motion.
This is why identical splice methods may perform differently on different feeders or placement platforms.
