Medical and Bio-Medical PCB Solutions
High reliability is of paramount importance in the medical industry. Because NexLogic understands this very well, we build medical products to J-STD-001C Class III standards. Our certified, highly qualified operators and technicians raise our already high bar to accommodate the more stringent demands of the medical industry.
NexLogic workmanship can be found in diagnostic and surgical equipment such as flat panel displays and surgical lasers. We work with some of the most recognizable names in the medical industry (i.e. Varian, Bio-Rad, Siemens, to name a few).
Reliability of PCB Products
- Burn-in and rigorous vacuum chamber testing are vital for medical electronics and circuit board products. Burn-in involves subjecting fully functional sub-system circuit boards to different temperature cycles to assure the full simulation as if the product is fully operational in a medical facility. Vacuum chamber testing puts the subsystem circuit board in a real environment, temperature ranges from -40°C to +85°C for 24 to 48 hour test cycles and it is put into non-stop operation for periods ranging from 24 to 72 hours. For example, such a circuit board could be in a remote location with temperatures over 100°F, and no air control rooms or, at the other extreme, with temperatures below room temperature or below freezing points thereby exposing the PCB to the extreme conditions ensuring 100% product reliability as well as finding latent defects.
- To achieve high reliability goals, a sound product testing strategy must be created at the prototype stage. That is when both OEM and EMS provider engineering staffs initially come together to discuss design and manufacturing objectives. In effect, the PCB prototype serves as a product R&D tool, allowing the EMS provider to increase reliability by defining and building in Design for Manufacturability (DFM) and Design for Testability (DFT) procedures within the different stages of the product development. Those include testing different environmental cycles that a circuit board undergoes to check voltage cycle, current, temperature and humidity. Then, there is environmental stress above and beyond regular in-circuit and functional testing. Failure rate analysis can be performed even at the prototype circuit board level to increase product yield and reliability.
- A first OEM developed prototype of a medical circuit board product, in most instances, operates at 60% – 80% percent of designed specifications. It rarely operates at 100 percent unless large dollar amounts and extremely talented and knowledgeable engineering resources are deployed along with lots of effort. In most cases, it is just the opposite. Few OEM engineers work on a prototype and generally speaking, their main focus is on testing a few initial features that comprise the core functionality of the product. Once that is achieved, they work on ancillary functions.
- While there continue to be countertop, wall plug-in medical electronics products on the market, there is a growing trend toward smaller, more compact and portable wireless devices deploying RF and Blue tooth technology. Medical products like these could be especially valuable in remote disaster struck areas like those hit by the Southeast Asia tsunamis in December 2004. Small form factor products like these are based on compact PCBs with tightly spaced digital and analog circuits. In these instances, correct device placement and partitioning on the PCB takes on new meaning and requires experienced engineering staff to achieve clean and undistorted signals, at critical levels.
- RF PCB Designs: correct placement and partitioning of power and ground planes is especially important for product designs that include radio frequency (RF) ICs. Hence, RF must be shielded properly and efficiently than other ICs by increasing the number of power and ground planes at the layout stage so that RF signals are sandwiched in between to keep the signal clean. RF is also shielded at assembly by using aluminum sheeting to block electro-magnetic interference (EMI). In effect, aluminum shielding acts as an antenna and radiates the EMI upwards into the air and away from adversely affecting other devices.