LED Soldermask – White, Browning Resistance

Current Resin Systems

  • Focus on initial thermal shock, not constant heat
  • Tend to brown over time
  • Not developed to a reflecting surface for LEDs

Desired Resin Systems

  • Remain white through Assembly and lifespan of LED final product
  • Have high reflectivity to enhance LED performance
  • Resulting in lower power consumption per same light output

Solution: White High Temperature LPI Soldermask

The new LED white soldermasks weren’t much of an improvement; consequently, SEC innovated our own solution.

2 Winners

We identified two offering demonstrating significant improvements. Find out more about them by watching the LED PCB webinar or setting up a free consultation with Yash Sutariya.

Resisting the Browning

One way to achieve a “SuperWhite” soldermask that resists browning is to apply a second coat of thermal cured white soldermask over the LPI. However, this can cause a concern that the second coat may impede the thermal dynamics of the PCB surface.

Thermal Images

Based on the thermal images below comparing a single coat of LPI to a board with a secondary coat, we can see that this is a non-issue.

Old coat

OldCoat OldCoat2

New coat

NewCoat NewCoat2