Many PCB manufacturing companies utilize FR4, the standard PCB manufacturing component, to produce PCBs. FR4 circuit boards are effective in many applications, plus they are also affordable. However, just because FR4 is the standard PCB manufacturing component doesn’t mean that there aren’t more component options that you can utilize. Some circuit board types require alternate materials to fit their functioning options.
One common alternate or substitute component you can utilize is known as Polyimide. Polyimide’s properties might help you generate a PCB that fits specific requirement criteria better than when you use FR4 or other components. However, before you utilize this material, you should know what it entails. You should also be able to answer the following questions: what are the benefits of working with Polyimide? Which applications best fit Polyimide? And when should you prefer Polyimide over FR4?
Polyimide in a Nutshell
Polyimides, which also go by the name polyamides, are incredibly effective polymers that encompass imide monomers. Moreover, these diverse polymers include a mixture of synthetic and natural components. For instance, natural polyamides may consist of the following:
However, in the production of Printed Circuit Boards, the polyamides that manufacturers utilize as board bases tend to be mass-produced synthetically.
Technicians produce polyimides by polymerizing particular chemicals that entail imide structures. In most cases, the production process of these polymers utilizes maleic anhydride and bismaleimides. The different additives and chemicals that technicians use to produce polyimides can produce varying results, generating varying polyimide types that provide varying advantages. Some major polyimide types include:
Pure Polyimide, which also goes by the name 2nd Gen polyimide, is developed without using additives and retardant brominate flames. As a result, these polyimides are more temperature resistant and have higher thermal stability than other polymers.
3rd Gen Polyimides
The 3rd gen polyimides include various additives that boost flammability resistance. Due to this feature, these polyimides can help prevent dangerous electrical fires that might damage the entire PCB or cause more terror. Moreover, while these Polyimides aren’t as thermally stable as pure polyimides, they provide better production times because of the lower production temperature and the time required to heal the circuit board.
These polyimide systems encompass a filler and Polyimide. The Polyimide in this mix helps generate efficient flexibility and thermal resistance. On the other hand, the filler reduces resin’s shrinkage, which helps technicians reduce the development of cracks in the drilling and curing process.
Low Flow Polyimides
The low-flow polyimides encompass a variety of flow restrictors and resins that reduce the material’s flexibility making it more rigid.
These are the most popular polyimide varieties; however, with time, experts predict that more polyimide varieties will gain popularity in the PCB sector. For instance, the 4th Gen polyimides are currently under development. These polyimides are expected to improve:
- CU (copper) foil adhesion
- Moisture sensitivity
- Overall stability
When should you Utilize Polyimide?
Though Polyimide is not the standard PCB production material, products made out of Polyimide are becoming popular in the market today, with their demand growing daily. The reason behind this demand growth is the fact that Polyimide is strong and flexible, which makes it a perfect fit for many applications. However, even though these are the primary reasons why most people are now turning to polyimide products, they are not the only reasons.
When selecting a base component for your printed circuit board, consider picking the materials that best fit your circuit board’s application. Therefore, Polyimide might be your best option if your printed circuit board application needs these circuit board characteristics:
Polyimides are famous due to their impeccable flexibility feature. Due to this reason, technicians primarily utilize them to produce rigid-flex and flex (flexible) printed circuit boards. Therefore, if flexibility is a significant factor in your circuit board functionality, you should go for Polyimide.
Impeccable Tensile Strength
Even though Polyimide is flexible, it is also pretty strong. Moreover, this component is warping-resistant. These two properties make Polyimide an excellent fit for applications needing physical durability.
Great Thermal Stability
Polyimide tends to be pretty stable at varying temperature ranges. Therefore, they can easily support regular PCB operation even at temperatures as high as 2600C. Moreover, these components have impeccable thermal conductivity and are thermal-damage resistant during their production and even during repair processes.
Polyimides are also chemically stable, which means that you can expose them to varying corrosive chemicals, and they will not be damaged. Therefore, if you plan on utilizing your printed circuit board in applications that expose the board to corrosive chemicals, then Polyimide might be your best base component option.
In addition to the fact that Polyimide components are chemical and heat-resistant, they are also resistant to immense physical stress. As a result, this component will retain its original shape even when you expose it to immense thermal and physical strain. Due to this feature, PCBs made of polyimides are ideal for application in harsh environments.
Applications of Polyimide Printed Circuit Board Material
Polyimide rigid-flex and flexible printed circuit boards have a lot of applications in the circuit board industry. These applications include:
21st-century automobiles heavily rely on electronics to function accordingly. To produce electronics that perform optimally in these automobiles, technicians primarily utilize flex PCBs made of Polyimide. Their flexible nature helps them handle intense vibrations.
Modern computer environments, for example, laptops, need some level of durability and flexibility for them to handle physical stress efficiently. Additionally, these environments heat up a lot which can cause thermal stress to printed circuit boards. However, technicians primarily utilize rigid-flex and flex PCBs made using Polyimide to cater to these needs. Due to their thermal stability, durability, and flexibility, they can handle these harsh conditions well.
Most consumer electronics, for example, tablets and smartphones, function via rigid-flex and flex PCBs. These PCBs can efficiently handle these environments’ physical and thermal stress.
Even though Polyimide Printed Circuit Boards are more expensive than FR4 circuit boards, they offer better flexibility and more significant functional benefits. Moreover, these circuit boards are durable, flexible, and lightweight, and they can solve so many printed circuit board design and integration issues. All these advantages make Polyimide components efficient and cost-effective options in the long run.