Thermal Management for EV Battery and Electronics Manufacturing

Now more than ever before, electric vehicle (EV) batteries and electronics must last longer, perform faster, and guarantee safety. Meeting those ever-increasing demands requires reliable thermal management.

The more power and capacity you pack into a small space – like a battery cell or a circuit board – the more heat it generates. Thermal management safely dissipates excessive heat away from a battery or electronic component so that it functions properly and does not combust.

• In EV batteries, this usually involves surrounding or encapsulating the part in thermal interface material (TIM), also known as gap filler.
• In electronics, TIM typically is dispensed directly onto the surface of electronic components.

Temperature plays a huge role in the longevity, efficiency and safety of a battery cell or electronic component.

• If the temperature is too low, power, capacity or performance can decrease.
• If the temperature is too high, degradation can occur, reducing the product’s life cycle. Too much heat also can cause safety risks that can have catastrophic consequences.

Keeping the temperature constant and evenly distributed is advised. Yet, reliable thermal management challenges manufacturers because excessive heat occurs for so many different reasons.

Therefore, batteries and electronics must be designed with thermal management systems that prevent overheating and safely guide the heat away from critical components.

Electric vehicle (EV) batteries and electronics can overheat – sometimes causing thermal events – because of overcharging, rapid discharging, or environmental factors. Ongoing optimization most often puts thermal management at risk.

• To improve EV battery performance and reduce weight, battery cells have a higher energy density that results in more heat generated inside a smaller space.
• To increase speed and decrease size, electronic components are miniaturized and functions are integrated, so that more can fit on printed circuit boards (PCBs) and confined spaces. The more compact and powerful PCBs become, the more heat they create.

During battery pack assembly, large volumes of thermal interface materials (TIMs), also known as gap fillers, are dispensed between the cooling circuit and the battery modules/cells. 

TIMs contain highly abrasive fillers with thermally conductive characteristics, allowing heat to be dissipated away from the battery cells or module towards the cooling circuit.

A printed circuit board (PCB) can consist of many components, and together, they generate a lot of heat. The top and bottom surfaces are where microchips, capacitors, connectors, resistors, and other components are mounted.

Heat can accumulate in the tiniest air gaps within the electronic device, causing the circuit board to overheat and stop working. That’s where thermal interface material comes in. 

TIM fills in those air gaps, so that the heat transfers quickly from the heat generating components to the heat dissipation components. This keeps the electronic device within an optimal temperature range, so that it works and lasts longer.

Thermal interface materials are very thick and pasty. TIMs also contain highly abrasive particles that can be as tough as diamonds. This combination quickly wears out and damages traditional industrial dispense systems. With frequent fixing or replacement of pumps, shafts and seals comes a lot of production downtime and maintenance costs.

Correctly mixing and applying thermally conductive materials also can be challenging. The pastes are often two component materials that necessitate precise, on-ratio dispense. It is crucial to dispense appropriate and even amounts to avoid air gaps or overflow.

To keep battery and electronic assembly lines in production with thermal interface materials (TIMs), they need dispense systems with these requirements:

• abrasive resistant components that withstand the harshest conditions
• accurate and repeatable dispense that properly distributes material for low or high flow applications
• data downloads - process data and job logs – that identify issues before they cause downtime
• easy integration into automation equipment