When to make use of flex

It’s getting more difficult to fit every little thing in the box; it’s additionally obtaining even more expensive. One solution promising to assist designers fulfill the size restriction head on is rigid flex PCB technology, yet many design teams try to stay clear of using rigid flex PCBs when item expense is an issue. Yet is it really as pricey as we believe?
To begin with, think about the cost of the conventional rigid-cable-rigid PCB assembly to one based on rigid-flex technology. The former building functions well for short-run styles; nevertheless, it requires adapters on each board and also the interconect, all of which drive up BoM price Additionally, the rigid-cable-rigid design is prone to ‘cool joints’, as well as decreased service life. On the other hand, rigid-flex circuits get rid of these joints, making them much more able and also reliable to deliver overall greater product high quality as well as long life. So while rigid-flex PCB technology is absolutely not new, different considerations now make it a lot more practical– not the least which is expense.

Simulate the cost.
In some styles, rigid flex will certainly not be a feasible choice, as well as you have to do your due diligence in determining the break-even factor where the costs have to do with equal. This type of price simulation can be done by taking into consideration the complete priced estimate expenses for fabrication as well as assembly. The PCBs can be quoted prior to design, as long as the specifications of design are well understood (for example, the layer stack, approximated using room, track as well as count ratios, etc.).
We carried out a manufacturing price simulation with a genuine rigid flex design and a comparative rigid-cable-rigid matching. The component BoMs for comparison differed only in the cable and also connectors needed for the non-flex version. For our simulation, the traditional design is consisted of four-layer boards that make use of flexible cable television and also ports in between them, while the rigid-flex design is a four-layer PCB with two internal flex layers. Manufacturing price for both designs is based upon real PCB fabricator quotes, as well as includes the expense of assembly.

Find your break-even factor

As the job volume portrayed in Figure 1 strikes 100 devices, the rigid-flex design becomes a more cost-efficient alternative compared to the typical design method. An essential reason for this cost financial savings is that rigid-flex circuits do not use connectors/cables or call for any type of port assembly. They feature increased reliability and procedure returns. That’s merely the tip of the iceberg.
Due to the fact that rigid flex PCBs call for no wire assembly, their overall assembly effort is reduced, as is their examination complexity– both which drive down price. Furthermore, less elements should be purchased, lowering the supply chain danger. Rigid flex PCBs can be developed to make item maintenance easier and consequently, even more affordable throughout the product lifecycle.

Exactly what about design time?

While the cost of manufacturing, assembly, screening, and also logistics are crucial consider considering the feasibility of rigid flex PCB modern technology for any offered growth, design and also task expenses can not be overlooked. Rigid flex PCB design usually requires the mechanical group to aid with the flex portion of the design, and PCB combination with the final product. The process is extremely time consuming as well as pricey, in addition to prone to mistakes.
Making issues worse, PCB design devices usually overlook the folding and also fitting elements of rigid flex design. Rigid flex technology design requires developers to function and believe in 3D. The flex portions can be folded up, turned as well as rolled to comply with the design of the mechanism. Standard PCB design devices do not sustain 3D board design or the definition and simulation of bends as well as folds up in the flex part of the design. They don’t even sustain the interpretation of different layer heaps in different parts of the design, including the locations consisting of the design’s flex part.
As a result of this, rigid-flex developers have been forced to manually equate both the rigid and also flex areas of their 3D design into a level, 2D depiction suitable for fabrication. Then they need to by hand record all locations of the design that are flex, and also check that no elements or vias have been placed near the changes in between the design’s flex and also inflexible portions. This process is controlled by numerous additional regulations, the majority of which are, not also remarkably, not supported by many PCB design software application.
In general, the extra initiative it has required to design rigid flex PCB as compared to standard rigid PCBs using typical PCB design software application has actually made them a lot less set you back affordable. Thankfully, contemporary design devices with innovative 3D capacities, and assistance for the meaning and simulation of bends as well as folds up in the flex section of the design, as well as the interpretation of different layer stacks in different parts of the design, are now available. These tools generally remove the have to handle the flex part of the design with mechanical CAD tools, saving developers and also design groups both time and money.

Design in 3D to make sure success

Early sychronisation in between the designers as well as the circuit board manufacturer, supported by the usage of a modern-day PCB design device, is one more aspect making rigid-flex modern technology a more cost-effective option. Rigid-flex layouts need closer collaboration between the developer and producer compared to traditional inflexible board styles. The tradeoffs called for to create a successful rigid-flex design mean a set of design regulations the developer can establish with the producer’s input. These factors to consider include the number of layers in the design, materials choices, recommended sizes for traces and vias, attachment techniques, and also dimensional control. With the appropriate design tool, these factors to consider can be clearly specified and also given the proper weight they are entitled to early to make sure that the rigid flex PCB can be correctly maximized, additionally enhancing its overall cost too.

There’s no denying that existing sector patterns and also consumer demands are pressing designers and design teams to their limits, compeling them to look for new options to the electronic design difficulties they currently deal with. These challenges, and particularly the needs being positioned on today’s mobile devices, are pushing rigid-flex modern technology into the mainstream, and also making it much more readily sensible for a variety of applications. The accessibility of modern-day PCB design tools that sustain 3D product advancement, very early cooperation, and all essential rigid flex meanings as well as simulation substantially minimize the discomfort of rigid flex PCB design as well as make it a lot more convincing option– one that under the right scenarios is less expensive compared to rigid-cable-rigid PCB design. For today’s design groups, that selection could just suggest the distinction in between item success or failing.