»
PECM
• Miniaturization: like many other critical industries, heat exchangers can benefit from optimizing space and miniaturizing components, allowing space for other parts in a given system or to improve lightweighting.
Semiconductor manufacturing is seeing an especially pronounced development in thermal architecture design improvements. Gas distribution plates and micro-perforated metal plates used in vacuum systems must deliver extremely uniform gas flow across the wafer surface, while also operating within tightly constrained tool volumes. Achieving this level of process control often requires thousands of precisely positioned microholes or internal flow passages, which push engineers towards denser, more intricate component geometries that are able to maintain consistent flow distribution and thermal stability throughout the system. The aerospace world is encountering something similar: propulsion technologies and high-power avionics generate much higher heat loads than they did previously, within increasingly compact platforms. For reference, advanced fighter aircrafts dissipating roughly 10-20x more onboard heat than platforms did in the 1970s, with total aircraft heat rejection rising from roughly 20-30kW to well over 300kW in modern fighters. Similar, high-power avionics and radar systems can produce tens to over 100kW of heat. Engineers are thereby turning towards micro-featured heat exchangers with integrated internal cooling passages to maximize heat transfer performance while also minimizing weight and volume( ideal for fuel efficiency).
Line-of-sight and material limitations Be it CNC milling, wire EDM, laser drilling, photochemical etching or other subtractive methods, a core principle remains: manufacturing a component requires direct access to the surface being processed, and the overwhelming majority of manufacturing processes still rely on this. CNC tools require physical contact with the material, EDM requires some form of electrode positioning relative to the feature, and laser machining requires optical access to deliver energy to the surface. In practice, this means the tool must maintain a clear path to the geometry being machined. The moment that path becomes obstructed( internal channels, curved passages, surrounding structures and more) the effectiveness and accuracy of these processes begins to degrade. This constraint is especially problematic as modern components increasingly rely on these internal geometries. Dense microchannel networks, perforated plates containing thousands of microhole arrays, and serpentine cooling passages all depend on extremely tight dimensional tolerances and controlled surface finishes in order to function properly. However,
these features are often buried deep within the component, beyond the reach of traditional tooling approaches. Even when access can be partially achieved, maintaining consistent tool alignment, removing burrs, or achieving uniform surface quality inside these confined geometries becomes even more difficult for manufacturers as feature density / internal complexity increase. And these issues are spread across a variety of tough-to-machine materials, including many grades of stainless steel. For instance, industrial fluid systems or UHP vacuum components are produced from high-grade stainless steel, including flow plates, vacuum chamber hardware, or chemical delivery components, in order to improve their corrosion resistance and long-term strength in elevated temperatures. Yet these stainless components still require sub- µ m finishes in non-line-of-sight areas, largely due to their strength, work hardening behavior, and tendency to generate high cutting forces.
Solutions to internal challenges In response to these accessibility challenges, manufacturers have developed a variety of workarounds to finish internal features. As a few examples, abrasive flow machining, vibratory finishing, and chemical polishing are sometimes used to improve internal surfaces where direct tool access is limited. But, in other cases, components may be intentionally split into multiple sections so internal channels can be machined before final assembly, followed by brazing or welding to rejoin the part. These approaches are also double-edged swords: abrasive or chemical processes may lack precise dimensional control, while multi-piece assemblies can add manufacturing complexity and introduce potential distortion or surface defects during joining. However, for many components whose most critical surfaces exist beyond the reach of traditional tooling, electrochemical machining( ECM) offers a fundamentally different approach.
Complexifying internal features in heat exchangers like these are beginning to include geometries outside of conventional tool access. www. heat-exchanger-world. com Heat Exchanger World May 2026
21