Medical technology is continually evolving and incorporating computerized solutions which has in turn led to the evolution and incorporation of printed circuit boards, abbreviated for PCBs. Today, medical devices are becoming increasingly affordable, and user-friendly due to PCBs.
Due to the medical industry standards, medical PCBs need to demonstrate the highest standards of precision, and reliability. In addition, they need to meet all the quality standards of the regulatory bodies. In this article, we discuss medical PCB, its requirements, applications, and challenges in detail.
Medical PCBs are a crucial component of various medical devices that are used by everyone from patients to doctors, nurses, and other healthcare professionals on a day-to-day basis. Due to their flexibility and reliable components, medical PCBs are implemented in a wide array of electronic medical devices.
Medical PCBs require a thorough approach to design and development that must include various critical segments of electrical, manufacturing, and regulatory areas.
The layout of medical PCB is an extremely critical aspect of the medical device manufacturing process. A medical device PCB layout ensures that the manufactured medical device is reliable, and as per the expected quality standards.
PCB for medical devices have stringent requirements in areas of design, performance, and quality. It should also meet the various regulatory requirements to ensure patient safety and reliability. Let’s understand some consideration factors when designing PCB layouts for medical devices:
Precision is one of the most crucial aspects of a medical PCB layout. Thus, the layout should be designed to ensure that the medical device can operate as per the requirements for its entire service life.
The PCB medical layout must be designed to reduce the risk of signal integrity issues. It should be optimized to avoid crosstalk, ground bounce, and signal reflections.
The medical PCB layout should be designed and optimized to minimize the risk of electromagnetic interference (EMI) and electromagnetic compatibility (EMC). It is thus recommended to maintain signal integrity and minimize EMI and EMC risk through careful stackup design, routing, filtering, and shielding.
The next factor that must be considered in medical PCB layout is the Design for Manufacture (DFM) and Design for Assembly (DFA) guidelines. In order to maximize the efficiency of PCB assembly, DFM and DFA guidelines must be followed and adhered to.
IPC Class 3 requirements ensure that the PCB boards are safe and reliable, and maintain a long life cycle. Thus, it is considered to be best practice for medical PCB to be by IPC Class 3.
Medical PCB is incorporated and applied to a wide range of medical devices. These applications improve the quality of medical devices and drive innovation. Let’s understand the various applications of medical equipment PCB:
PCBs are applied for monitoring systems such as blood glucose monitoring and diabetes management. They are also applied in wireless blood pressure readers where monitoring is possible via smart phones. The requirement of PCB in such devices is reliability and a long lifespan.
PCBs are incorporated in call and healthcare alarms of hospitals. These systems are used to alarm the nurses and doctors. It is required that these call and alarm systems are highly reliable and have a long life span.
Medical PCB is often applied in medical devices for sensing, analysis, and delivery of oxygen. Such medical PCB device solutions need to demonstrate high reliability.
PCB is incorporated in various medical devices such as CT scanners, Ultra-sonic and MRI equipment. PCB in medical imaging must demonstrate a high-speed signal that has integrity and controlled stack-ups.
PCB is incorporated in protective healthcare devices such as air respirators. PCB in such devices powers and purifies air respirators that are used by healthcare specialists in critical scenarios.
PCBs are applied for surgical theatre lighting systems. They need to be able to manage heat and demonstrate a long lifespan.
The above applications are just to name a few. Medical PCB is also applied in life support ventilators, gas analyzers, blood test and pressure, x-ray calibration, endoscopes, medical gas administration devices, smartphones and tablets for mobile health applications, wearable medical devices, 2D and 3D Sensors, response stimulators, etc.
Medical PCBs must meet various requirements to ensure reliability and patient safety. These stringent requirements present some challenges. Let’s understand some of these challenges:
You should note that medical devices are often exposed to extreme environments and they must be able to not only perform in every environment but also deliver reliable results.
Medical devices with PCBs are applied to various medical situations that can range from diagnostic to life-saving devices. Thus, they need to be extremely reliable.
Medical PCB often needs to be miniaturized so that they can fit in small medical devices. There are thus size constraints. These size constraints require a PCB specialist who can carefully craft miniaturized PCBs.
If PCB is manufactured for medical devices, then it needs to be manufactured as per Class 3 electronic requirements. Thus, it is crucial to consider a PCB manufacturer that is seasoned in producing Class 3 electronics. In addition, medical PCB must also adhere to installation, operation, and process qualification standards.
Medical PCBs are applied in a variety of devices and equipment that typically have size constraints. In the medical sector, it’s popular to employ flex and rigid-flex circuit boards. They are manufactured with flexible and lightweight materials that make it easier to fit into compact and smaller spaces of medical devices. Such types of circuit boards are capable of condensing and incorporating highly complex components into a small space.
Let’s understand the various types of medical PCB:
The material type in PCB manufacturing for medical devices is crucial to ensure that each medical device meets the required safety standards. There are various consideration factors for choosing the correct material and substrate for medical PCB such as:
Since medical PCBs are for internal use, they need to demonstrate the utmost patient safety which is why they are typically coated with FR-4 (Flame Retardant Level 4), polyamide, Teflon, PTFE (Polytetrafluoroethylene), or ceramic material. These coatings act as heat deterrents that further divert heat thus, preventing the medical devices from being damaged.
There are various types of PCB technologies but medical PCBs are typically manufactured either through surface mount technology (SMT), or plated-through-hole technology (PTH). Let’s understand these technologies further:
SMT, abbreviated for surface mount technology, enables manufacturers to incorporate smaller components, thereby reducing medical PCB’s size. It also helps to increase the component density on the board.
You should also note that the assembly of SMD components doesn’t require the technicians to drill holes, thereby reducing the costs and time.
Although SMT is one of the popular technologies for most PCBs, some designs require the incorporation of the plated-through-hole mounting technology. This is especially the case for power supply boards or if multiple connectors are implemented.
HDI, abbreviated for high-density interconnects, supports the requirement of components in high density. It enables medical device manufacturers to drastically reduce the size of PCBs through laser-made via holes.
HDI technology achieves a high component density by frequently employing a significant number of interconnections and via holes.
Via-in-pad technology is particularly employed in the case of highly integrated components. E.g. BGAs or along with numerous pins.
The via-in-pad technology allows holes to be directly created on the pads, thereby establishing connections with internal layers.
PCBs are critical components of medical devices that ensure their functionality. They thus have stringent quality, and regulatory requirements. Let’s understand the various compliance requirements in this section:
ISO, abbreviated for International Organization for Standardization, guidelines a detailed quality management system (QMS) that regulates the design and manufacture of medical devices. You should note that the development process follows a well-defined Quality Management System that monitors and analyzes potential risks.
ISO 13485:2016 is the updated Quality Management System for PCB manufacturers and ISO 9000 outlines quality requirements for PCB design and assembly. In addition, ISO 14971 outlines the application of risk m
