Datasheet

LUXEON LED Assembly and Handling Application Brief AB32 20121217 3
1. Component ................................................................................................................................................................ 4
1.1. Description ........................................................................................................................................................ 4
1.2. Optical Center .................................................................................................................................................. 4
1.3 Lens Handling .................................................................................................................................................... 8
1.4 Lens cleaning ...................................................................................................................................................... 8
1.5 Electrical Isolation............................................................................................................................................. 8
2. Board Design Rules ................................................................................................................................................... 9
2.1 PCB Requirements ........................................................................................................................................... 9
2.2 LUXEON LED Footprint and Land Pattern ............................................................................................... 9
2.3 Surface Finishing ..............................................................................................................................................11
2.4 LUXEON LED Close Proximity Placement .............................................................................................11
3. FR4-Based Boards ................................................................................................................................................... 11
3.1 Material Properties .........................................................................................................................................11
3.2 Optimal Thermal Design ...............................................................................................................................11
3.3 Thermal Via Design .........................................................................................................................................13
3.4 Component Spacing .......................................................................................................................................15
3.5 Thermal Resistance ........................................................................................................................................16
3.6 FR4 Board Handling .......................................................................................................................................20
4. MCPCB Board design ............................................................................................................................................22
5. Assembly Process Recommendations and Parameters ..................................................................................24
5.1 Stencil Design ..................................................................................................................................................24
5.2 Solder Paste .....................................................................................................................................................25
5.3 Pick and Place Nozzle ....................................................................................................................................25
5.4 Pick and Place Machine Optimization ........................................................................................................28
5.5 Placement Accuracy .......................................................................................................................................31
5.6 Reflow Profile .................................................................................................................................................. 32
5.7 Reflow Accuracy .............................................................................................................................................33
5.8 Void Inspection and Solderability Indicators ............................................................................................34
6. JEDEC Moisture Sensitivity Level ........................................................................................................................36
7. Product Packaging Considerations – Chemical Compatibility .....................................................................37
Table of Contents