Afternoon Agenda Deciding on your soldering equipment and important factors to consider on configuration for a robust process Reflow

In general machine created process defects are more to do with original configuration decisions and daily set up understanding rather than actual machine faults

One equipment contributor to reflow defects is the wrong oven size or the wrong number of zones

The wrong size oven leads to incorrect profile for the paste and the product and will lead to defects

Reflow The basic requirement of any Reflow oven is to be able to consistently reflow your product at the required speed to meet production needs Calculation is Process speed = Heated Length (inches) Paste Dwell (minutes)

Example Reflow system needs to process at 30”/minute with 4 minute paste dwell profile Heated Length = 30 x 4 = 120”(3M) Not all ovens have same heated length per zone Note this is NOT total oven length More zones will allow for greater process controls and zone definitions which allows for tighter profile control

Important factors for consideration Air or Nitrogen Flux maintenance Thermal performance Power consumption Cooling capability active or passive Other factors

Air or Nitrogen Air systems run invariably cleaner N2 will widen the process window Pin in paste type applications may influence need for secondary flux management systems due to flux amounts (GRS)

Global costs Nitrogen added expense

Flux management Typical GRS System Flux laden gas passes through condensation system and removable filters out side of the tunnel for ease of maintenance

Affect of heater cell design on power consumption and T Efficient design of heater cell increases thermal transfer rates and decreases T Lowers overall cost for energy Can allow for shorter total oven heated length resulting in lower overall cost of ownership

Heater cell design affect on power usage and costs Poor heater cell design results in much higher KW usage and slow reaction to loading which results in slower throughput ability or increased T

Cooling Cooling rate is a key component on joint integrity and strength Product density, size and complexity will determine your need Cooling affects the time above liquidious Active cooling needs to be considered

Active cooling Passive cooling involves using make up fresh air only and will heat up during the day causing TAL issues Active cooling involves using recirculated liquid and heat exchangers and will maintain down to 50 F Below this temperature an external chiller is needed

Other automatic options assisting process Automated recipe generation based on PCB type saving multiple profiling time

To ensure you have a robust process pay attention to the machine configuration and daily set up Don’t ignore the cooling section Have the machine automate decisions based on certain criteria