sales@ipcb.com
How to make flexible pcb is based on knowing what a flexible pcb is?
Simply put, a flexible printed circuit board, or flex PCB for short, refers to an electronic circuit board that can be bent, flexed or folded. To achieve this, PCBs are usually made of a thin and flexible insulating material called polyimide, in which conductive but flexible copper traces are printed and etched. As you know, the role of a PCB or printed circuit board is to establish connections between various components within an electrical or electronic device. While rigid PCBs have dominated the market for many years, the emergence of flexible pcbs has opened the door to new possibilities due to their dynamic characteristics.
The production process of flexible pcbs is as follows:
1. Design: Design a flexible pcb based on the needs and functional requirements of the product. Factors such as line width and line spacing, interlayer distance, and rigid-flexible joints need to be considered during the design process.
2. Make a film: According to the FPC pattern drawn by the design, the required pattern is generated on the conductive layer through processes such as chemical etching or photolithography. This step usually uses materials such as photoresist and photosensitive coatings.
3. Soft board production: The conductive layer and the insulating layer are pressed together according to the design requirements to form a flexible pcb. This step usually requires the use of equipment such as a heat press.
4. Inspection and repair: The produced flexible pcb is tested for electrical and physical properties to detect whether there are problems such as open circuits and short circuits. If problems are found, they need to be repaired.
5. Completion: After testing and repair, the production process of the flexible pcb is over. Subsequent assembly and use can be carried out.
The bare board of the flexible printed circuit board is made of flexible materials and can be bent and manipulated according to the requirements of the designer. This feature of bendability and flexibility is very useful in making various new-age gadgets such as wearable devices.
Classification of flexible printed circuit boards
Flexible PCB manufacturers can now design, manufacture and customize PCBs of various specifications. Although the variations are great, flexible circuit boards can be roughly divided into several types according to their number of layers and configurations.
By number of layers: single-sided, double-sided and multi-layer flexible pcbs
According to the number of layers of the flexible printed circuit board, it can be divided into single-sided, double-sided and multi-layer PCBs. Each type has its own advantages and characteristics. Although more layers allow more components to be connected, the complexity and overall cost also increase. Therefore, Viasion engineers carefully study the project requirements to find the type of flexible printed circuit board that best suits the application.
• Single-sided flexible pcb: Single-layer has only one conductive layer and is currently the most commonly used flexible printed circuit board. It has the excellent electronic and mechanical properties of flexible materials and is low cost, so it is widely used in consumer electronics.
• Double-sided flexible pcb: Double-layer flexible circuit boards have two layers of copper, connected by plated through holes, combining high electronic performance with cost-effectiveness. They are usually used in high-volume high-tech electronic devices such as laptops, cameras, headphones, etc.
• Multi-layer flexible pcb: For such very advanced devices that require very limited space or continuous movement, we need to use multi-layer flexible pcb boards, such as robots, industrial equipment, and medical applications. This type of flexible pcb has three or more copper layers. But in general, we recommend using more than four copper layers in flexible pcbs, which affects flexibility.
By Features: Standard Flexible PCB, Rigid-Flex and HDI Flexible PCB
Similarly, based on the configuration, flexible circuit boards can be divided into standard flexible pcb, Rigid-Flex PCB and HDI flexible pcb.
• Standard Flexible PCB: Standard flexible pcb is the most commonly used flexible circuit board. They are usually made of polyimide with one or two conductive layers and stiffeners.
• Rigid-Flex PCB: As the name suggests, rigid-flex PCB has the characteristics of both rigid and flexible pcb. In this type of flexible pcb board, only the required area of PCB is made of flexible material, which helps to connect the rigid part of the circuit. This reduces the cost while allowing the PCB to bend as needed.
• HDI Flexible PCB: HDI flexible pcb or high-density interconnect circuit board can be considered as an advanced version of flexible pcb. They have better functions and better performance than ordinary flexible printed circuit boards.
Differences between flexible pcb and rigid PCB
Rigid and flexible printed circuit boards work on the same principle, and their main function is to connect various components within electrical or electronic devices. However, the two differ in terms of physical flexibility as well as some other features such as heat resistance, durability, manufacturing process, and price.
Rigid PCBs are the traditional PCBs that you might think of when you think of PCBs in general. As the name suggests, they are rigid, non-bendable, and physically non-flexible. They are made of materials such as glass fiber reinforced epoxy resin, which provide excellent mechanical strength, support, and structure to the device. Similarly, flexible printed circuit boards are made of flexible materials such as polyimide, which have the unique property of being able to bend.
Rigid PCBs are the traditional PCBs that you might think of when you think of PCBs in general. As the name suggests, they are rigid, non-bendable, and physically non-flexible. They are made of materials such as glass fiber reinforced epoxy resin, which provide excellent mechanical strength, support, and structure to the device. Similarly, flexible printed circuit boards are made of flexible materials such as polyimide, which have the unique property of being able to bend.
What are the benefits of flexible circuit boards?
Flexible circuit boards are widely used in most industrial fields. The reason for the surge in demand for flexible printed circuit boards is their unique features and numerous advantages.
The assembly process is simplified due to the reduced number of connection points. Higher packaging density, i.e. reduced packaging size. Negligible possibility of defects, such as solder joint defects and wiring errors, higher reliability than rigid PCBs. Increased design freedom, resistance to extreme environments such as vibration and chemicals, enhanced heat dissipation and better airflow. Lower assembly costs due to the elimination of wire harnesses and uncomplicated testing processes. Shorter assembly time can further reduce costs and high-density configurations can be achieved.