Transient response and thermal safe operating area extension of dual-heat-source vapor chambers for high-performance laptops

As high-performance laptops evolve toward ultra-thin form factors, extreme thermal loads and severe nonlinear thermal coupling within their CPU-GPU multi-chip modules limit reliability and sustained performance. This paper develops a dual-heat-source vapor chamber (DHS-VC) with a heterogeneous composite wick to overcome heat transfer limitations in confined spaces, introducing a two-dimensional safe operating area (SOA) for global thermal evaluation. Under a constrained 3.0 mm thickness, localized porous copper foil and directional flow guides effectively mitigate liquid supply bottlenecks caused by competition between the dual heat sources. Under the high-load condition of 120 W–120 W, startup time was only 1051 s, 5.8%–31.1% shorter across the operating-condition matrix than that of the pure mesh-wick control sample. Across five alternating-load cycles, the device showed favorable dynamic liquid redistribution: no abrupt temperature excursion from local capillary dryout occurred, and inter-cycle temperature consistency was maintained. At steady state under the equal-load condition of 190 W–190 W (380 W total), the minimum overall thermal resistance reached 0.032 °C/W; under the unequal-load condition of 280 W–60 W, the local peak heat flux reached 58.33 W/cm 2 . Quantitative SOA evaluation corroborates the outward expansion of the cooling boundary: relative to the pure mesh-wick control, the outer envelopes bounded by the 100 °C physical limit are essentially comparable, whereas the 75 °C SOA area of the DHS-VC is enlarged by 26.0%, markedly widening the safety margin for sustained, throttle-free operation. This study provides theoretical and design guidelines for thermal management of integrated electronics, enabling higher dissipation limits and broader safety.