Simulation-Based Investigation of PCB Thickness Effects on DC–DC Buck Converter Performance in Laptop Motherboard Voltage Regulator Modules at Elevated Temperatures

Abstract

Laptops are getting smaller and more powerful, putting a lot of heat stress on motherboard parts, especially voltage regulator modules. As these devices shrink, their temperatures go up during heavy use, causing excess heat to build up. This trapped heat makes the power system unstable, leading to power loss and crashes. Because of this, cooling the system is no longer just about adding fans; we must rethink how the motherboard is built. This study looks at how printed circuit board thickness affects heat control and electrical performance in a buck converter running at high temperatures. To do this, the study used a physics-based AI assisted simulation instead of building physical prototypes. A multiphase buck converter (12 V input, 0.5–2.0 V output, 35 A total load) was modelled. The evaluation varied PCB thickness (0.8–4.0 mm) and ambient temperature (35–100 °C). The results indicate that conversion loss increased consistently with ambient temperature across all board thicknesses. Thicker boards, particularly near 4.0 mm, trapped heat, causing a drop in efficiency to approximately 81% at 100 °C. Conversely, thinner boards exhibited lower thermal resistance and maintained higher conversion efficiency. Based on the electro-thermal simulation, board thicknesses between 1.2 mm and 1.6 mm offered a favorable thermal baseline for high-performance laptop VRMs.