7/11/2007 >>

 

“PROfile tools” - the new thermal profiler solution...

 

One of the issues facing production engineers when starting a new production job is

how to start when setting up a soldering thermal profile for a convection reflow oven.

 

PROfiler tools 2008 software aims to enhance speed and ease the process set-up.    

             

Taking into account the solder paste, oven and component specifications

the software is able to simulate a target thermal profile and decide relevant oven

settings before a thermal profile run has ever been made.

This eliminates the need for repeated thermal profile runs, which can take time and

reduce production throughput.

 

A built-in library of common reflow soldering ovens can simplify the initial input of

basic characteristics such as physical zone lengths although custom oven

configurations may be added by the user if necessary.

 

The process recipe specifies the temperature settings which are applied to the heating

and cooling zones in the oven, along with the line speed.

 

An additional solder paste library contains the rules extracted from various solder

paste manufacturer process specifications. These include such as maximum

temperature, liquidus time and temperature, soak times etc.

The thermal profile of the target features can then be tested against the solder

paste rules, any violations of the rules can then be used to derive an appropriate

recipe change.

 

Using the oven characteristics and its recipe, the software constructs a model of

the air temperature profile to which the intended PCB would be exposed.

 

The tools include a library from which the appropriate features can be selected for

modeling; this equates to selecting the positions on an actual PCB to which

thermocouple probes might be attached as per IPC7530.

 

The software then uses an air temperature profile to predict the thermal profiles

of target features on the PCB according to their thermal mass, thermal resistance

and physical dimensions. In fact these attributes get combined into a single characteristic

time constant value.

 

One of the software tools analyses actual recorded thermal profile data. It can extract

the time constant values of probed features, which may then be added to the feature

database.