All of the critical reflow profile and process data are measured including slope, peak temperature, time above liquidous, etc.
The reflow oven profiling software also measures the Process Window Index™ (PWI) statistic.
The PWI identifies your reflow profile’s ‘fit’ to the process window. A single number which indicates how well the reflow profile suits the board, solder paste and oven.
A PWI less than 100 indicates an in-spec profile. The lower the PWI the more your process is centered within the process window.
The PWI shows instantly where your process or the oven needs to be adjusted.
Setting the software up for profiling is easy.
The reflow profiling software needs to have the oven details entered, zone quantity, lengths and belt speed.
The solder paste can be selected from the list, most popular solder pastes are listed or you can define your own process spec.
The process spec. is contained within the solder paste type that is selected.
This is the solder paste manufacturers recommended process window.
These specifications include Slope, Preheat, Soak, Peak temperatures, and Time above
Once the oven and process has been set the board can be prepared for profiling.
The air thermocouple (channel 1) is attached to the PCB so it extends 25mm in front.
The air TC triggers the start of the profile automatically when the temperature rises.
This ensures the profile starts at the right time and there is no need for the operator to start the profile.
The other thermocouples are attached to key components and areas of the board, all channels of the data logger should be used.
A more accurate reflow profile will be created when more areas of the board are logged.
The reflow profile is now ready to start.
When the operator clicks on the start button they are prompted to put the data logger and board in the reflow oven.
Once the data logger exits and PCB exit the oven the data is downloaded and the reflow profile information is displayed.
The PWI is displayed indicating if this reflow profilw is within spec. or not.
The profile can be examined manually in more detail.
Automatic reflow profile optimisation is available using Autofocus or Navigator
Changes to the reflow oven zone temperatures are created to automatically bring the reflow profile within spec. if required.