Solder pastes tackiness: the influences of the process atmosphere and of the test method

During the assembly of surface-mounted devices, a storage time may exist between screen printing and infrared reflow. For this reason, solder pastes have been characterized by their tackiness. Results given by two methods of tackiness measurement are presented in order to choose the more appropriate method for the present application. Tackiness evolution was observed during the storage of screen-printed circuits for different atmospheric compositions. A correlation between the pastes' tackiness and the intrinsic characteristics of their vehicles has been established. It is shown that the tack time is improved by storage of the screen-printed circuits in a dry atmosphere.<
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