Can flexible circuit boards withstand extreme temperatures?
flexible circuit boards withstand extreme temperatures
A flex circuit board’s materials and construction are vital to its maximum operating temperature capability. The conductive copper in the substrate film, adhesives used to bond the layers together and shielding films used for EMI-sensitive applications all have different maximum operating temperatures. The FR-4 and Kapton base materials have different maximum operating temperatures and the thickness of a stiffener (to support component/connector areas, for example) affects the overall flex circuit maximum operating temperature as well.
Most flex PCBs are exposed to high temperatures, including those during autoclaving for medical equipment or when they’re used in drilling equipment. They must also be able to handle extreme heat and cold, as well as vibrations.
In order to withstand these extreme conditions, a flexible circuit board copper traces must be able to dissipate the heat they generate, or the temperature will continue to rise and eventually damage the components on the circuit board. This is why choosing a higher-grade rolled annealed copper foil is often recommended for flex circuits that will be bending and moving all the time. This material can stretch longer before fatigue cracking and is springier in the Z deflection direction – perfect for a flex circuit that’s going to be bending and rolling all the time!
Can flexible circuit boards withstand extreme temperatures?
Flexible circuit boards are also able to withstand higher temperatures because they’re made of durable materials like polyimide. These materials can easily withstand high temperatures, and offer resistance against acids, oils and gasses. This makes them ideal for a variety of applications and environments.
Another important factor in determining the maximum operating temperature for a flex circuit board is the thermal cycle tolerance of its copper-to-substrate and copper-to-resin interconnections. Thermal cycling is a process that involves subjecting the circuit board to multiple cycles of heating and cooling. The goal is to replicate the operating environment of the circuit board over a period of time in a laboratory setting. A typical flex circuit board can be subjected to up to 10 thermal cycles, which will not cause any structural damage to the conductive layer or the base layer.
Lastly, the thermal cycling tolerance of a flex circuit board is determined by its CTE (coefficient of expansion) contrast between its resin and copper. Choosing matierals with similar CTEs will help to ensure that the vias on the flex circuit board don’t crack under stress.
A flex circuit board can be assembled with a variety of components and connectors, including crimped contacts, ZIF connectors and direct soldering. They’re able to accommodate these types of attachments because they’re designed with a range of dimensional tolerances. This allows for more design flexibility and makes it easier to fit the circuit board in the desired location. They’re also able to bend 360 degrees without any electrical faults, making them a great alternative for rigid circuit boards in a variety of applications.