Last week Patently Apple posted an IP report titled "Apple Invents a new Thermal Module for Future MacBooks, Mac Desktops and iPads running Higher-End Processors." Today the U.S. Patent Office published yet another patent application of Apple's covering a possible future thermal module for high-end MacBooks and iPads.  

Apple's patent background states that notebooks continue to use advanced integrated circuitry (e.g., system on a chip, or SOC) for various complex processing functions. This may cause the integrated circuitry to operate for longer durations and at higher frequencies. As a result, the heat (e.g., thermal energy) generated during operation of the integrated circuitry tends to increase. Current thermal modules (e.g., heat spreaders), relying significantly on thermal conductivity of its components, may lack the necessary thermal transport capabilities.

High-End MacBooks & iPads with a Looped Thermal Module having a Unidirectional Valve

Apple's invention covers thermal modules that promote unidirectional, or one-way, flow of substances, such as liquids and vapor, used to transport heat. Thermal modules described herein may include several flow barriers that take the form of stationary structures (e.g., stationary flow barriers) extending from a base or housing part. The flow barriers may take the shape of a herringbone, a chevron, or a V-shape, as non-limiting examples. Collectively, the flow barriers may function as a valve (e.g., one-way valve, check valve) that promotes a unidirectional and uniform flow of a refrigerant used to transport heat. Additionally, thermal modules described herein may include one or more voids. The flow barriers may cause vapor to circulate, or flow around, the void in a loop. Based in part on the flow barriers causing the unidirectional flow, thermal modules described herein may provide a thermal transport capacity, Q.sub.max (in Watts per meter-degree), several times greater than traditional thermal modules. Beneficially, thermal modules described herein may be used in more thermal applications in which heat generation (e.g., in electronic devices) becomes increasingly higher, and where space constraints limit the use of conventional thermal modules of comparable thermal transport capacity.

Based in part on the shape and spacing of the flow barriers, the refrigerant, in a gas state (e.g., vapor, gaseous state, gas phase), can flow around the flow barriers with minimal restriction provided by the flow barriers. However, when the refrigerant flows in the opposite direction, the flow barriers may block or substantially restrict the flow. In this regard, the flow barriers provide a pressure differential that causes flow bias in an intended direction, thus limiting the flow to a (generally) single direction.

Thermal modules may include additional features. For example, a thermal module may include an evaporator section that receives heat and causes (based on the received heat) a phase change of a refrigerant from a liquid state (e.g., liquid phase) to a gas state. In the gas state, the refrigerant may flow as pressurized vapor from the evaporator region through an additional, intermediate section to a condensation section, where the heat is dissipated from the refrigerant and converted back to its liquid state.

Based in part on causing a flow bias, the flow barriers may cause the refrigerant to flow in one general direction (thus preventing or limiting flow in the opposite direction) from the evaporator section to the condensation section via the intermediate section. The condensation section is designed to condense the refrigerant from the gas state to the liquid state. However, in the condensation section, when some of the refrigerant is still in the liquid state, the refrigerant may take the form of a liquid-vapor mixture, e.g., a mix of refrigerant in the liquid and gas states. The refrigerant may be transported the refrigerant to the evaporator section via capillary wicking through, for example, the valve, with the pressurized vapor from the refrigerant in the gas state and the capillary pressure in the valve providing a force to push the refrigerant.

Additionally, one or more wick structures may provide additional capillary pressure. Thus, the refrigerant may circulate in a unidirectional, two-phase (e.g., gas and liquid) cooling loop through the thermal module.

Apple's patent FIGS 1A and B point to the devices the new thermal solution is designed for; FIG. 2 illustrates an exploded view of an example of a thermal module; FIG. 9 illustrates an example of a thermal module that includes channels.

Apple's patent FIG. 13 above illustrates an example of a thermal module with multiple openings; FIG. 15 illustrates a block diagram of a thermal module with a pump.

One of inventors listed on the patent is Anthony Aiello, Product Design Engineers, Thermal Design.  

Another related patent was published today titled "Thermal Management Module of an Integrated Circuit Assembly."  That one covered all Apple devices (iPhone, Apple Watch, iMacs, MacBooks, iPads). For more on this, review patent application 20240395660.