Rigid-flex PCB Board Design Solves Wearable Medical Gadget Difficulties
The vast majority of electronic circuit boards at this present time are merely rigid plates for connecting circuitry. But, that is changing fast; the interest in flex PCB boards (or flexible circuits) is promptly increasing in large part thanks to the flourishing wearable device industry. Probably the largest segment of that market is the healthcare industry in which wearable devices will be employed to get all varieties of biological records for examination and research, and also individual health use. Undoubtedly wearables are available to keep tabs on heartbeat, blood pressure levels, glucose, ECG, muscle movement, and even more.
The wearable devices present a lot of challenges for PC board designers that rigid boards do not. The following are some of such problems and what designers can perform to ease them.
3 Dimensional Design
While every PCB board is certainly three-dimensional, flex circuits allow the entire assy to be bent and folded to conform to the package that the product occupies. The flex circuitry is folded so the rigid electronic circuit boards fit into the item package, occupying space.
There are lots more to the design, therefore, the further challenges, than just connecting the rigid boards. Bends should be exactly designed so boards line up where they’re intended to mount, while not placing force on the connection points. Up until recently, engineers actually used “paper doll” models to imitate the circuit board assembly. Right away, design tools are obtainable that offer 3D modelling of the rigid-flex assembly, helping more rapidly design and significantly greater precision.
Little Products and Squeezed Circuits
Obviously, wearable products have to be tiny and unobtrusive. In the past, a healthcare “wearable” like a Holter pulse rate monitor integrated a reasonably large exterior device with a neck strap or perhaps belt mount. The new wearables are tiny and install straight to the patient with no or very few external cables. They gather a variety of data and are able to even process a handful of analyses.
An subtle device attaching straight to the sufferer demands flex circuitry and extremely compressed layouts. Additionally, the board shapes are often round or even more unconventional shapes, requiring brilliant placement and routing. For such tiny and dense boards, a PC board tool that’s improved for rigid-flex designs can make addressing strange shapes less difficult.
Stackup Design is very important
The stackup – the map of the electronic circuit board layers – is critical when working with rigid-flex techniques. If at all possible, your PCB design software has the capability to design your stackup including both the rigid and flexible parts of the assembly. As mentioned earlier, the layout of the bending area needs to be designed to prevent the pressures on the traces and pads.
One of the largest difficulties with rigid-flex designs is qualifying several manufacturers. After the design is fully gone, every aspect of the design must be communicated to the board fabricator so that it will be properly manufactured. Yet, the best practice is to pick one or more makers at the start of the design and work together with them to make certain your design suits their manufacturing requirements as the design goes forward. Working together with manufacturers is made easier by using standards. In such a case, IPC-2223 is the vehicle for getting in touch with your fabricators.
After the design is done, the data package must be assembled to hand-off to be manufactured. Though Gerber continues to be utilized for standard PCBs in a few companies, on the subject of the difficulties of rigid-flex, it is highly recommended by both PCB software tool vendors along with manufacturers that a more intelligent data exchange format be employed. The 2 most sought-after intelligent formats are ODG++ (version 7 or higner) and also IPC-2581, as both versions clearly indicate layer requirements.