Introduction:
The development and wide application of flexible PCB are due to its remarkable advantages. First of all, its agile structure, tiny volume, light weight, good quality, which are satisfied the requirement of contemporary electronic product. Secondly, it can extend to three dimensional space, and improve the freedom of circuit design and mechanical structure design. These advantages not only reduce the workload of the whole machine and assembly errors, but also greatly improve the reliability and high stability of the electronic equipment system as a whole.
Pretreatment:
In the process of production, in order to prevent the low yield caused by too many defects such as open/short circuit, or reduce the scrap rate and the feeding frequency caused by these coarse process problems such as drilling, rolling, cutting. And then, assess how to choose the material in order to meet customers’ requirements and manufacture the flexible PCBs which can achieve the best effect. All above these show that the pretreatment is especially important.
Manufacturing Process:
Double-side Flex-PCB:
Cutting → Drilling → PTH → Electroless Plating → Pretreating → Dry Film Lamination → Position → Exposure → Develop → Pattern Plating → Remove Dry Film → Pretreating → Dry Film Lamination → Position and Exposure → Develop → Etching → Remove Dry Film → Surface Finish → Coverlay Lamination → Lamination → Curing → Immersion Gold → Silkscreen → V-cutting/scoring → Electrical Test → Punching → FQC → Packaging → Shipment
Single-side Flex-PCB:
Cutting → Drilling → Dry Film Lamination → Position and Exposure → Develop → Etching → Remove Dry Film → Surface Finish → Coverlay Lamination →Lamination → Curing → Surface Finish → Immersion Gold → Silkscreen → V-cutting/scoring → Electrical Test → Punching → FQC → Packaging → Shipment
Size and Weight Reduction Benefits to Flexible Circuitry:
Generally, flexible circuitry is the go-to solution for manufacturers who need:
1. Wiring solutions that fit where rigid boards cannot.
2. Thin, lightweight products that are nonetheless durable.
3. Miniaturized versions of existing technologies.
4. Three-dimensional packaging geometry.
5. A low number of device interconnects.
6. Shock and vibration resistance.
These benefits point to flexible circuitry options as an ideal solution for mobile consumer electronics. Enterprising circuit board amateurs who take apart their smart phones or laptop computers will find a wealth of flexible circuitry inside any modern device on the market.
In the case of mobile devices, the use of rigid circuitry would result in a device too large, too heavy, and too fragile to conveniently carry around. This was the case with the Osborne I, the first fully powered mobile computer, which weighed in at an intimidating 24.5 pounds.
Size and weight reduction represent only one half of the flexible circuit story, however, they are also ideal for high temperature and high-density applications.
High Temperature and High-Density Applications:
In many cases, flex circuits are made of polyimide or a similar polymer. This material dissipates heat better than most rigid circuit board materials. For this reason, flexible circuits can be placed in inconvenient locations where heat would impact the performance of a rigid circuit board.
Flexible circuit boards can be designed to withstand extreme temperatures – between -200° C and 400° C – which explains why they are so desirable for borehole measurements in the oil and gas industry.
In fact, because of these conditions, and the need for small, unobtrusive devices in most industrial environments, flexible circuits represent the first choice for engineering design in most industrial sensor technologies.
High temperature resistance comes usually comes with good chemical resistance and excellent resistance to radiation and UV exposure as well. Combined with the ability to control impedances in high density circuit board designs, flexible circuit designs offer many benefits to manufacturers.
Why Not Make All Circuit Boards Flexible?
Flexible circuit boards are certainly useful, but they are not going to replace rigid circuit boards for all applications. Cost efficiency is the main obstacle to implementing an exclusively flexible circuit board design in a consumer product. Rigid circuit boards are less expensive to manufacture and install in a typical automated high-volume fabricating facility.
Typically, the ideal solution for an innovative product is one that incorporates flexible circuitry when necessary, and employs solid, reliable rigid circuit boards where possible to keep manufacturing and assembly costs down.
Some manufacturers even use hybrid rigid-flex printed circuit boards expressly for this purpose. This is common in laptop computers and medical devices, where rigid circuit boards can be connected to one other using ribbon-like flexible circuits. These boards can be compounded and designed to meet any number of engineering needs by focusing on the respective strengths of each circuit board base technology.
PCBWay creates both flexible and printed circuit boards for product manufacturers. Enjoy a consultation with one of our sales reps to find out if your product prototype design is best served by flexible or rigid circuit board types.
