Reduce Your PCB Costs with Rigid-Flex PCB
Whether you are making your first simple prototype circuit or trying to refine and redesign a bulky gadget, you have to make a choice. The choice of what kind of PCB you are going to use. Most people prefer to go with the tried and tested Rigid PCB, because of its simple design and cheaper cost. Why pay extra for a complex Rigid-Flex circuit when you can get the desired results from a much cheaper Rigid PCB, or the relatively cheaper option of using Flex PCB with stiffeners if you require a 3-dimensional circuit.
For the most part, you will be correct. A rigid PCB is much cheaper than Rigid-Flex, but only to an extent. If your design is complex enough that you need to design and interconnect four or more rigid PCBs together, the overall cost of your circuit will be significantly lower if you use a Rigid-Flex PCB.
And it’s not just design complexity where a Rigid-Flex wins. Depending upon your product requirement, you may need a static (needs to be bent once to install) or dynamic circuit (constantly needs to bend). This is where a Rigid-Flex PCB is better compared to a simple Flex PCB with stiffeners.
Let’s take a look at how Rigid-Flex PCB manufacturing can actually reduce the overall cost of your PCB.
Reducing Cost with Rigid-Flex PCB
If you compare the bare cost of a Rigid PCB and a Rigid-Flex PCB, the Rigid-Flex appears thoroughly more expensive. This is why it is important to take a broader perspective.
Product Design Flexibility
A circuit is designed according to the product. Most products nowadays are getting smaller and smaller. Even if your product design allows you a lot of space for your PCB housing, more compact design will definitely reduce the cost of the device, needing fewer materials.
A Rigid Flex PCB is always smaller than conventional Rigid PCBs since it allows for three-dimensional designing. If you go with a Rigid-Flex instead of a Rigid PCB, you may design your circuit according to your product, rather than designing your product to accommodate your circuit. This design flexibility allows you to reduce the overall cost.
It is also important to note that when you use multiple Rigid PCBs, each PCB is designed separately and is allotted an individual part number. When you combine all rigid PCB units to complete your PCB, your total circuit will have a number of different elements, each with its own part number. A Rigid-Flex, on the other hand, is always considered a single circuit. As a single component for your device, no matter how complex it is, it will only require one part number.
No Cables and Connectors
Since Rigid-Flex conducts using traces, there is no need for wires and connectors. This doesn’t just eliminate the cost of wires; it creates more space on the PCB. When there aren’t any connectors, the leftover space can be used to install further components, increasing the component density of the circuit. This makes the circuit compact, as well as lighter.
No cables and connections also reduce the cost and time of soldering. The lack of connectors means a lack of potential failure points of the PCB.
Assembly and Testing
Let’s say you are using five Rigid PCBs in your circuit; they will each require separate assembly. Every PCB will have to be individually kitted, inspected, and fabricated. Each Rigid PCB will go through its separate cable assembly test and final product test, and each unit will incur separate tooling costs.
Now if you were to design the same circuit for a Rigid-Flex PCB, one assembly will be required, it will be kitted, inspected, fabricated, and finally tested only once and will be subject to a one-time tooling cost. It doesn’t require a cable assembly test as well.
This is why Rigid-Flex manufacturers might charge you less for the same circuit than if it were in Rigid PCBs.
Though this doesn’t come under the cost of getting your circuit manufactured, it is definitely important when the circuit is installed in the product it was designed for. Rigid-Flex is more thermally stable, more efficient, more shock and vibration resistant, and more durable than Rigid PCBs, and even Flex with stiffener circuits. They are able to weather harsh environments better and are therefore favored for devices used in military and space operations.
If your circuit is supposed to be employed in high precision, compact, and robust devices, designing a functional and reliable Rigid-Flex circuit is better than deploying a conventional Rigid circuit that will be complex, bulky, and more prone to damage.
Some Important Tips
There are some design mistakes engineers tend to make when designing a Rigid-Flex circuit for the first time. They should be avoided to prevent the additional testing and redesigning cost of your Rigid-Flex PCB. You should make sure that:
- Vias and Microvias should at least be 30 mm away from the edge adjoining the Flex to the Rigid part of the PCB.
- Consult your Rigid-Flex PCB manufacturer about their production limitations before working on impedance controlled designs.
- Flex turns should be as gradual as possible.
- Employ as fewer flex layers as possible.
A Rigid-Flex circuit, if carefully and efficiently designed, can save you a lot of money in terms of testing, assembling, and buying components than a conventional PCB circuit. This is especially true if you work with specialists. We can help you improve upon even your most compact Rigid-Flex circuit.
Advance capabilities of our Polyimide Rigid-Flex circuits include the flex thickness as low as 12 micrometers and rigid thickness of a mere 30 micrometer. With our design production capabilities of producing up to 30 layers and 360-degree bends, you can design amazingly efficient circuits for wearables, medical implants, and other compact devices.
If you opt for using HDI PCBs, your options can become even more diverse.