1. Single-sided flexible board
Lowest cost. When the requirements for electrical performance are not high and single-sided wiring is possible, the single-sided flexible circuit board should be selected. This most common form has been used in commercial applications, such as ink cartridges of printers and memories of computers. The single-sided flexible board has a layer of chemically etched conductive pattern, and the conductive pattern layer on the flexible insulating substrate is rolled copper foil. The insulating substrate used for flexible assembly can be polyimide (Kapton), polyethylene terephthalate (PET), aramid fiber paper (Nomex) and polyvinyl chloride (PVC).
2. Double-sided flexible board
Double-sided flexible circuit board is a conductive pattern etched on both sides of the base film. Metallization connects the patterns on both sides of the insulating material to form a conductive path, so as to meet the design and use function of flexibility. The covering film can protect the single-sided and double-sided wires and indicate the placement position of components.
3. Multilayer flexible board
Multi-layer flexible circuit board is to laminate three or more layers of single-sided flexible circuit board or double-sided flexible circuit board together. Metallization holes are formed by drilling and electroplating, and conductive paths are formed between different layers. In this way, a complicated welding process is not needed. Although the number of conductive layers designed in this type of flexibility can be unlimited, in order to ensure the convenience of assembly, the interaction between assembly size, number of layers and flexibility should be considered when designing the layout.
4. Rigid-flexible combination type
The traditional rigid-flexible bonding plate is composed of rigid and flexible substrates selectively laminated together. Compact structure, forming conductive connection with metallized holes. Considering the reliability and price factors, the manufacturer should try to keep as few floors as possible.
HDI Rigid-flex board: High Density Interconnection,HDI) rigid-flex printed circuit board belongs to high-end printed circuit board products, and its goal is to meet the demand that electronic products grow towards miniaturization, high frequency, high speed and multi-efficacy. HDI rigid-flexible joint board combines the advantages of popular HDI board and rigid-flexible joint board, which promotes the high integration and intelligent growth of electronic system design and manufacture, and has been widely used in high-end electronic products such as aerospace skills, medical equipment and expenses.