The Model 1200 Table-Top Vacuum Solder Reflow Station has been designed for process development and low volume production of Flux-Free and Void-Free soldered joints in microelectronic packages and components. The station is easy to use and profile for a wide variety of soldering tasks. A ramping temperature controller is combined with customized PLC’s to provide automatic process control.
The aluminum process chamber is accessed via a manually locking lid for rapid entry and sealing. The heated work area is located at the top of the chamber for easy access. A large viewing window in the cover provides invaluable assistance in determining the proper processing temperatures for solder reflow.
Heat is provided by radiant energy emitted from a uniform resistive graphite heating element. The radiant energy heats a removable flat hot plate which may be machined with cavities to hold the parts to be soldered. The hot plate is typically made from high emissivity graphite, but may also be metallic. A single type K thermocouple inserted directly into the hot plate monitors the process temperature and provides feedback to the proportional temperature controller. A polished radiation shield minimizes heat loss, and excess process chamber heat is dissipated directly with water cooling.
Control of the processing atmosphere is integrated with the temperature controller through automatically actuated solenoid valves. An external vacuum pump is used to rapidly evacuate the chamber. Nitrogen gas (used for cooling and process) and one additional inert gas can be introduced into the chamber via ports in the cover and chamber bottom. Flow rates and pressures are set on the operator control panel. Void-Free solder joints are most reliably obtained through a carefully controlled and sequenced combination of heat, vacuum and pressurized inert gas.