A base material has several crucial roles to perform in a flex circuit board. The material is responsible to electrically insulate conductive circuit tracks from one another. It also provides the circuit with flexing strength and durability.
When it comes to manufacturing flex circuit boards, there are several base material options available. However, choosing the right base material determines the quality and performance of the final assembly.
This blog familiarizes you with two commonly used base materials in the assembly of flex circuit boards.
Polyimide or Polyester, Which One to Choose?
Being a crucial component in flex circuit boards assembly, it is important to choose the right base materials with:
- High dimensional stability
- Exceptional thermal resistance
- Low moisture absorption
- Good tear resistant
Amongst several options, polyimide and polyester are largely chosen for their excellent electrical and mechanical properties.
- Polyimide – These are non-flammable thermoset polymers exhibiting good flexing and electrical properties. They can withstand elevated or fluctuating temperatures. In addition, they possess excellent thermal stability, good chemical resistance, very low creep, and excellent tensile strength.
- Polyester – The material is characterized by its outstanding electrical properties, chemical, and moisture resistance. Polyester is compatible with several manufacturing techniques, including drilling, punching, embossing, thermal forming, coating and dying. This base material is cheap compared to polyimide, making it the perfect solution for high volume flex circuit boards.
Your decision between polyimide and polyester must be based on several factors. Before choosing one material, consider the application environments, production volume, intended service period of the applications, and electrical requirements, manufacturing methods, and overall costs. Have a discussion with your manufacturer regarding selecting base material as per the applications. He will have a lot more things to tell you about the both base materials.
