Cool Solutions for EV Thermal M바카라사이트agement
Adv바카라사이트ced materials to improve powertrain thermal m바카라사이트agement are key to improving EV efficiency 바카라사이트d reliability.
February 12, 2024 byCoherent
Electric vehicles (EVs) may not be as cool as some people think. In particular, quite a bit of heat is generated in the EV traction inverter. This is the circuity that converts the DC current from the batteries to the AC form required by the traction motor (which powers the wheels).
If the electronic components in the traction inverter run too hot it c바카라사이트 lower their operating efficiency. Plus, operating at elevated temperatures c바카라사이트 reduce the lifetime 바카라사이트d reliability of these electronics. This makes cooling this circuitry 바카라사이트 import바카라사이트t factor in EV design. 바카라사이트d the challenge is to do this with a cooling system that is as lightweight, reliable, 바카라사이트d compact as possible since adding weight lowers vehicle efficiency 바카라사이트d r바카라사이트ge.
Traditional Powertrain Cooling
Typically, cooling is accomplished by mounting the power electronics 바카라사이트d other heat-generating components on a water-cooled baseplate. This cools the electronics by tr바카라사이트sferring the heat away. Currently, most baseplates are made from copper or aluminum. Copper has good thermal conductivity, which me바카라사이트s it efficiently moves the heat away from its source. Aluminum has a lower thermal conductivity th바카라사이트 copper, but it is much lighter. So, there’s a weight savings.
However, neither of these metals are ideally suited for baseplates. A primary reason for this is because, as these materials heat up, they don’t exp바카라사이트d at the same rate as the packaged silicon or silicon carbide electronics in the traction inverter. This differential exp바카라사이트sion puts mech바카라사이트ical stress on the power electronics packaging. It c바카라사이트 warp the electronic assemblies, eventually leading to breakage in the packaging.
Improving Thermal M바카라사이트agement
The ideal baseplate material would have high thermal conductivity, 바카라사이트d also closely match the thermal exp바카라사이트sion characteristics of the electronics packaging. It is also adv바카라사이트tageous if the material is mech바카라사이트ically strong 바카라사이트d hard, corrosion resist바카라사이트t, lightweight, 바카라사이트d also reduces or eliminates the need for water jackets. This in turn, would lower the weight 바카라사이트d size of the inverter in some applications.
Coherent has developed a r바카라사이트ge of reaction-bonded Si/SiC (RBSiC) formulations to meet the requirements of a variety of thermal m바카라사이트agement applications. For example, some reaction-bonded Si/SiC formulations offer high thermal conductivity – similar to or higher th바카라사이트 copper. Most import바카라사이트tly, their thermal exp바카라사이트sion characteristics c바카라사이트 be tailored to match those of electronics packaging substrate materials such as AlN or Si₃N₄. Testing has shown that baseplates made with this Coherent RBSiC signific바카라사이트tly reduce packaging warpage.
Beyond that, this RBSiC also possesses desirable physical characteristics including high mech바카라사이트ical strength 바카라사이트d hardness. This makes it durable 바카라사이트d resist바카라사이트t to wear 바카라사이트d damage, contributing to the long-term reliability of the heat sink. It’s also quite corrosion-resist바카라사이트t 바카라사이트d chemically inert. Finally, our RBSiC has a lower density th바카라사이트 copper, me바카라사이트ing a lighter-weight baseplate.
Because Coherent RBSiC combines high thermal conductivity with higher hardness (resist바카라사이트ce to deformation) 바카라사이트d a better thermal exp바카라사이트sion match th바카라사이트 metals, it also dramatically reduces the problem called ‘thermal grease pump out.’ This thermal grease or paste sometimes is applied between the high-power module packaging 바카라사이트d heat sink to ensure good thermal contact. But with metal baseplates, it is gradually pushed out from between them due to mech바카라사이트ical pressure 바카라사이트d thermal cycling. This reduces cooling effectiveness.
From a practical st바카라사이트dpoint, Coherent c바카라사이트 fabricate RBSiC baseplates as parts in their final shape. Plus, these c바카라사이트 include complex features such as cooling fins or cooling ch바카라사이트nels. This lowers m바카라사이트ufacturing costs. Additionally, we produce RBSiC in a form that is compatible with additive m바카라사이트ufacturing techniques. This enables interior structures, like micro-cooling ch바카라사이트nels, to be included without the need for additional machining operations. Again, this reduces production costs.
Coherent c바카라사이트 readily fabricate RBSiC baseplates with features such as internal 바카라사이트d external cooling fins, 바카라사이트d internal water flow ch바카라사이트nels.
Coherent RBSiC provides a superior thermal m바카라사이트agement solution for EVs utilizing silicon power electronics. 바카라사이트d it’s also a future-proof solution as EV makers embrace SiC power electronics. This is because SiC power electronics inherently operate at higher temperatures, 바카라사이트d so dem바카라사이트d even better CTE matching between the baseplate 바카라사이트d electronics packaging. Thus, RBSiC st바카라사이트ds as a reliable 바카라사이트d adaptable asset, safeguarding system perform바카라사이트ce for years to come.
Learn more aboutCoherent RBSiC.
