Abstract: A control method includes obtaining a theoretical discharge pressure according to a geometric parameter of an outdoor unit of a multi-split air conditioner, an air supply port parameter of an indoor unit of the multi-split air conditioner, an outdoor ambient temperature, and an indoor ambient temperature, obtaining a pressure deviation according to a high pressure of the outdoor unit and the theoretical discharge pressure, and performing starting control of the multi-split air conditioner according to the pressure deviation.

Abstract: An apparatus includes a printed circuit board (PCB), and an integrated circuit (IC) package connected with the PCB. The IC package includes a package substrate, a die secured to the package substrate and including an integrated circuit, and a stiffener ring secured to the package substrate and surrounding so as to define a perimeter around the die. The stiffener ring increases a rigidity of the package substrate and delivers electrical power to the integrated circuit, where the stiffener ring includes a first conductive layer forming a power (PWR) plane for the integrated circuit, a second conductive layer forming a ground (GND) plane for the integrated circuit, and an insulating layer disposed between the first conductive layer and the second conductive layer.