Medical PCB Assembly and Manufacturing
High-end medical PCB - the gospel of electronic medical industry
PCBA boards are an important part of today’s electronics industry, enabling machines to improve and advance. While printed circuit boards are used in many electronic devices, including LEDs, water dispensers, and air conditioners, their use in medical device is one of the most cutting-edge applications.
Medical PCB is a specific type of PCB used in the medical industry. As China’s medical industry shifts from traditional Chinese medicine to Western medicine, the demand for medical electronics has dramatically increased. This has prompted the development of China’s medical PCB manufacturing and assembly technology, making FS Technology a reliable medical equipment PCBA manufacturer. The medical circuits produced by FS Technology are widely used in a range of medical devices, including ultrasound machines, patient monitoring equipment, medical imaging systems, and other devices that require precise and reliable electronic control. These PCBA play a crucial role in controlling and regulating the electronic functions of medical equipment.
Get a Medical PCB Fabrication and Assembly Quote from FS Technology
If you’re looking for a top-tier manufacturer of medical PCBs/PCBAs, go no further than FS Technology. Since medical electronics are related to human health, they must meet strict safety and reliability standards. For example, most PCB manufacturers can provide basic certifications such as ISO9001 and ISO14001. However, it is far from enough for a company like FS Technology that has medical PCB manufacturing capabilities and provides medical PCBA services. We must meet medical industry standards such as ISO 13485 certification. In addition, some implantable medical electronics require greater accuracy and stability, so they need to be designed to withstand harsh medical environments, more testing is involved in manufacturing, and soldering of components needs to be ensured during assembly quality etc.
What medical electronic PCBs have been produced?
Since the outbreak of the COVID-19 pandemic, the global demand for medical electronics has remained high. In this environment, FS Technology has received many inquiries from the medical industry. Currently, the majority of the medical PCBA we produce are for electronic forehead thermometers. However, we also manufacture PCBAs for other medical devices such as CT scanners, surgical lights, and a range of other products. The following are some examples of the PCBAs for medical products that we can provide to our customers:
Medical PCBA Standard
Potential hazards are rigorously monitored and assessed throughout the development process of medical devices. Several different types of testing are used to ensure conformity to these criteria. Here are some of the most important standards that FS Technology follows:
- ISO 9000 or 9001: Addresses the quality and dependability criteria in designing, manufacturing, and testing electronic products.
- ISO 13485: This is a quality management system (QMS) standard specifically designed for medical device manufacturers. It sets requirements for the entire product life cycle, from design and development to production and post-market surveillance.
- IEC 60601: This is a series of international standards that cover the safety and effectiveness of medical electrical equipment. Particular attention is given to protection against electric shock, mechanical hazards, and radiation.
- IEC 61010-1: Safety rules for measuring, controlling, and lab equipment that uses electricity.
- IPC-A-610: This is a standard for the acceptability of electronic assemblies, including PCBs. It covers requirements for soldering, cleanliness, and other aspects of PCB production.
- FDA 21 CFR Part 820: This regulation from the US Food and Drug Administration (FDA) outlines the QMS requirements for medical device manufacturers. It covers areas such as design controls, production controls, and device labeling.
- UL 94: This is a flammability standard for materials used in electronic products, including PCBs. It sets requirements for the resistance of materials to flame and ignition.
- CFR 820: For verifying production and quality control.
Focus of Assembling Medical PCB
The reliability of medical PCB applications is crucial, whether they are used in the operating room or the lab. There is no room for equipment malfunctioning or performing incorrectly in the medical field. Therefore, the following PCB assembly practices are essential to creating a circuit board for use in medical devices:
- The PCB design should take into account the specific requirements of the medical device, including the component count, board size, and thermal management requirements.
- It is essential to position components carefully and route traces properly to ensure a successful board.
- Component Selection is critical in creating reliable medical devices. It is important to find the best components that meet the specific requirements of the medical device, and are reliable, durable, and have a long lifetime.
- Choose a medical PCB assembly factory with a good reputation or a PCBA fabricator with experience serving the medical industry. Ensure that they can manufacture high-quality circuit boards.
- The use of lead free PCB assembly is considered an efficient practice, and selecting a company dedicated to sustainability can bring unexpected benefits to your project.
- The PCB cleaning process is particularly important in medical electronics. While the purpose of cleaning is typically to avoid short circuits caused by surface stains during use, in medical equipment, residual cleaning agents may harm patients.
- The assembled circuit boards must undergo thorough inspection and testing to ensure that they meet the required standards for reliability, performance, and safety.
- To ensure that electromagnetic interference (EMI) does not affect the medical PCB, engineers should refer to various EMI standards.
Medical PCB Manufacturer: From Design to Assembly
The manufacturing process for medical PCBA is a specialized and crucial process. Prior to beginning mass production of circuit boards, it is essential to create a medical PCB prototype to ensure the reliability and functionality of the PCB for medical equipment or instruments. Through the use of a prototype, manufacturers can more accurately assess the success of the board and make design and manufacturing adjustments as needed. This ensures that the final medical equipment PCBs comply with medical industry standards and are capable of precise and reliable control of electronic functions that are critical to the safety and effectiveness of medical devices. Additionally, PCB prototyping helps to prevent losses during mass manufacturing, improving production efficiency and cost-effectiveness.
Given that these PCBs are essential for ensuring the health of patients, it is evident that meeting standards alone is not sufficient. FS Technology is committed to fulfilling such orders with even stricter implementation standards. The following is the production process of the medical circuit board:
Medical PCB Design
Step 1: Medical Device PCB Schematic
A PCB schematic is a visual representation of the electronic components and connections that constitute a printed circuit board (PCB). Therefore, the first step in manufacturing and assembling a medical PCB is to perform a schematic design. The schematic depicts the electrical connections of the components and how they connect to form a circuit. Usually, this process is carried out by the medical electronics manufacturer. If you do not have the necessary expertise or are a foreign trader, choosing FS Technology as your medical PCBA supplier is a wise decision. We provide EMS services to assist you in completing this process.
In this step, the customer must provide all the essential information about the medical project to the medical PCB manufacturer to produce basic drawings. Some crucial details include the intended use of PCB, type of circuit board, the required power, and the material used. All of these details must be accurate, and the initial design of the medical PCB should be based on them.
The schematic offers a clear overview of the circuit, enabling engineers to identify potential issues and make necessary adjustments before proceeding to the fabrication and assembly phases. In a schematic diagram, components are represented by symbols, and connections between them are depicted by lines. These symbols are standardized, making it easy for circuit board components identification. For instance, a resistor is typically represented by a zigzag line, while a capacitor is denoted by two parallel lines.
Step 2: Layout of Medical Electronic Components
To ensure reliable and efficient operation of medical PCBA boards, it is important to plan a reasonable layout of PCB components (SMD components and DIP components) and PCB bare boards.
In modern medical electronic devices, components are often laid out as close to each other as possible to reduce the size of the circuit board, especially in implantable medical devices. Additionally, careful consideration is given to the power requirements of the components, overall power consumption of the circuit, electromagnetic interference (EMI), and thermal management to ensure error-free manufacturing of medical PCBA boards.
Step 3: Medical Device PCB Design
The next phase after the initial schematic design is to create a layout for the medical printed circuit board (PCB). It is important to use professional PCB design tools and follow good PCB layout practices to avoid board-level failures. For medical devices, people’s lives depend on how well the PCB functions, making it necessary to not just follow best practices, but to consider them a requirement. The following are some considerations for designing medical PCBs:
- Keep trace lengths short and direct;
- Use power planes and ground planes to shorten signals from decoupling capacitors and to ensure good ground coverage;
- Construct high-energy traces and planes with sufficient copper to handle high power and minimal voltage drop;
- Use differential pairs or signals to reduce reflection for high-speed data traces;
- Keep clock signals short and away from other nearby traces or planes to prevent crosstalk;
- When overlapping traces from different layers, overlap them perpendicularly;
- Keep temperature-sensitive components away from other components;
- Check reflow soldering requirements twice to ensure that SMD parts stay cool while being assembled.
Step 4: Files for Final Work
To finalize the design, the last step is to send the Gerber or CAD data to the China medical PCB assembly manufacturer. Once the manufacturer approves your PCB design and final fabrication files, the PCB fabrication can begin, bringing your digitally designed PCB to life.
While there are many PCBA manufacturers worldwide to choose from, it is essential to look for ISO 13485 certification for medical PCB projects. If you are unsure about proceeding with the project, you can send the files and instructions outlined above to FS Technology. As the best among 1-10 layer medical PCB manufacturers, we can provide you with the necessary expertise and quality assurance.
Medical PCB Manufacturing
Step 1: Design Imaging
At this step, the medical PCB manufacturing factory becomes involved in the process. The medical electronics PCB board manufacturer utilizes a plotter printer to convert the design files for circuit boards into films, which serve as photo negatives of the diagram.
When the PCB is printed, the inside layers exhibit two colors of ink:
- Black ink represents the copper traces and circuits on the PCB.
- Clear ink, like the fiberglass base, represents the non-conductive PCB parts.
The outer layer has:
- Copper pathways that are displayed by clear ink.
- The area where the copper will be etched away is indicated by black ink.
Step 2: Inner Layer Printed Copper
This step in making a PCB marks the beginning of the actual PCB manufacturing process. The process starts with creating the base material of the PCB, which is a laminate board made from substrate materials. Typically, epoxy resin and glass fiber are used as the base materials.
In the process of making a PCB, the first step is to laminate a layer of copper to each side of the fiberglass substrate. The film is then aligned with the copper layer and placed on top of them, after which the entire stack is exposed to ultraviolet light. This process causes the transparent areas on the film to harden and protect the copper underneath. The board is then developed in a chemical solution, which removes the unhardened clear ink, leaving behind the copper traces and circuitry. The black ink on the film ensures that copper is only etched away in unwanted areas, leaving the desired circuit pattern intact.
If your electronic project requires a multilayer medical PCB, you will need to repeat the above steps until all the inner-layer circuits required by the multilayer PCB are printed and etched. These circuits are then aligned and laminated to form a complete inner layer.
Step 3: Combining Different Layers
After all the necessary inner layers have been etched, printed, and laminated, and the laminate has been cleaned, the layers are aligned and combined to form a complete printed circuit board. The outer layers of copper are then laminated to the stackup and connected to the inner layers by drilled holes.
As a professional turnkey PCB assembly company (manufacturing & assembly), every step of our manufacturing process is designed to pave the way for subsequent PCB assembly. For the medical PCB drilling process, we utilize an optical drilling machine to ensure precision. This is a machine that drives pins through alignment holes to align the inner and outer layers, ensuring the drilled holes’ effectiveness for subsequent through hole PCB assembly.
Consider the example of a medical pacemaker PCB, which requires the highest level of precision during the drilling process, as even the slightest error can result in a significant loss. A typical pacemaker PCB has over a hundred drill holes, and the drilling process takes a significant amount of time and resources.
Step 4: Medical PCB Outer Layer Imaging
Imaging the outer layer of a medical PCB is a crucial step in the PCB manufacturing process. Another photoresist is applied to the PCB medical panel, which involves transferring an image of the PCB design onto the copper layers on the outer surface of the board. However, for imaging, the photoresist is only applied to the outer layer. The process takes place in a clean and safe area.
The imaging process begins with cleaning the copper surface to ensure that no dirt or debris is present that could interfere with image transmission. Pins are used to hold black ink transparency sheets in place and keep them from getting out of line. After being coated with a photoresist, the PCB medical panel goes into the yellow room. The UV light blast hardens the photoresist, and the unhardened resist covered by black ink is removed.
Step 5: Outer Layer Etching
During this process, any copper that doesn’t belong in the outer layers is removed, and electroplating is used to add a layer of copper. Tin electroplating is used to protect copper in the critical areas after the first copper baths. Once the outer layer has been etched, the PCB panel is ready for AOI Inspection and soldering. AOI ensures that even the copper layer of medical aesthetic PCB boards with complex circuits meets the necessary specifications.
Step 6: Solder Mask
After that, the solder mask is applied to protect the outer layer of the medical printed circuit board and prepare it for the soldering process by hiding the parts that do not require soldering.
The medical PCB panel is first cleaned to remove any dirt or excess copper that may interfere with the application of the solder mask. An ink epoxy and solder mask film are then applied to the surface of the board. UV light is used to harden the solder mask where soldering is not required. The areas where the mask is not required are then removed, and the board is placed in an oven to cure the solder mask.
Step 7: Silk Screening
During silk screening, an ink-jet printer prints the details directly on the board. These details typically include the company ID, manufacturer’s logo, symbols, component numbers, pin locators, and other distinguishing markings or features.
Step 12: Surface Finishing
The nearly finished medical PCB requires a coating of conductive material according to customer specifications. This provides more space for soldering. After the coating process, the surface of the PCB will have a finish.
Medical PCB Assembly
PCB Assembly (PCBA) is crucial to making a medical PCB perform its intended function, and the integrity of the assembly process is critical to the functionality, safety, and reliability of the medical device in which the PCB resides. The complexity of medical PCBAs is directly proportional to the number of processes involved in making them and their price. However, if you already have a board and components, you only need a PCBA factory to do the final assembly work, which is very cost-effective. The following outlines the medical PCB assembly process of FS Technology:
Step 1: Solder Paste Stenciling
The solder paste stenciling technique is the first stage of the PCB assembly process. In this step, a stencil is used to cover the circuit board so that only the portion of the PCB board that will be mounted with a component is visible. This makes it easier to apply the solder paste solely to the board’s areas where the components will be placed.
A mechanical device is used to hold the board and the solder stencil in place so that this can be achieved. After that, an applicator is used to deposit the solder paste at predetermined locations. The solder paste is applied consistently over all of the exposed areas. Once this step is complete, the stencil is removed, and the solder paste is left in the appropriate locations.
Step 2: A Game of “Pick and Place”
Many medical electronic devices are either implanted in the human body or worn on sensitive organs. If these devices malfunction, such as by short-circuiting or burning out, they may cause secondary harm to the patient. Therefore, it is crucial to accurately place the components in the designated positions using precise equipment.
Implantable medical electronics, such as cochlear implants and artificial eyeballs, typically have many electronic components in their internal structure. However, smaller devices present challenges in the picking and placing process, making it more difficult to maintain precision. To achieve the high accuracy required for assembling PCBs for medical cochlear implants, FS Technology uses robotic equipment. Robots are responsible for picking and mounting surface-mount components onto circuit boards, ensuring that the components are precisely placed on the solder paste with the mounting mechanism.
Step 3: Soldering Reflow
The soldering reflow process is designed to strengthen the connections between the circuit board and electrical components. To achieve this, a conveyor belt is used to move the circuit board through a large reflow oven. The solder paste is melted by heating the PCBA board to around 2500 degrees Celsius during the process. After being heated in the oven, the medical PCBA goes through a series of coolers, which help the solder paste cool and harden, resulting in strong connections between the electrical components and the board.
It is important to note that for double-layered medical PCBs, the stenciling and reflowing processes are performed in a specific order. The side of the board with fewer and more manageable electrical components is completed first.
Step 4: Medical PCB Assembly Test
We have emphasized the precision, reliability, and importance of medical circuit boards, so it’s important to find reliable manufacturers and excellent PCBA processing plants and ensure they have ISO 13485 certification. Even if they meet these conditions, it’s still necessary to examine their PCB testing services and capabilities.
Although we include PCB testing in the assembly process, it should actually be a part of the entire project process, such as manual inspection throughout the entire process, SPI after solder paste printing, inner layer, outer layer, and AOI inspection after SMT assembly. The service provider you choose must have perfect PCB assembly inspection capabilities to ensure that your project proceeds smoothly, quickly, and affordably.
Step 5: Medical PCB Functionality Test
In the last stage of assembling Medical PCBs, the produced board undergoes inspection and testing. A comprehensive functionality test is conducted to ensure that the board performs as expected and meets the high standards set by the medical industry. After inspection, the board is cleaned to remove any oil, flux, or other waste that may be present. This ensures that the medical board is sterile and can be used in the production of medical devices. Specialized testing can also be conducted on the Medical PCB according to the specific type of medical equipment that will use the board.
Price of Medical Device PCBA
Compared to consumer PCBs, the manufacturing and assembly of medical PCBs are more expensive due to various factors, such as stricter requirements, costly components, and complex testing processes. FS Technology usually adopts IPC-A-610-G-1 as the minimum standard, which is valid for general electronics but not sufficient for medical electronics. Therefore, we have to adopt a higher standard, such as class 2 or class 3, which increases our costs as the difficulty rises. However, in order to provide better service to our customers, we offer medical PCBA services at a lower price, which is more cost-effective than our competitors.
Difficulties and Overcoming of Medical PCB Manufacturing
When compared to traditional PCBs, medicinal PCBs are notoriously difficult to manufacture. Manufacturers face the following difficulties:
- Medical PCBs often incorporate both through-hole and surface mount components, which can increase production costs. As medical devices become increasingly compact, such as wearable devices, PCB assembly becomes one of the most challenging aspects of manufacturing.
- Medical defibrillator PCBs often require the use of heat-sensitive SMD electronic components, and if not carefully selected, RoHS PCBAs may fail at high temperatures.
- Mismatched components can lead to equipment failure, and specialized components can be expensive, creating a challenge for medical electronics manufacturers. This is where turnkey PCBA companies can play a crucial role. Using autoclavable or washable components can help lower the cost of medical PCB assembly.
High-end medical PCB
HDI PCB, which stands for “High Density Interconnect Printed Circuit Board,” is one of the most commonly used types of printed circuit boards in advanced medical equipment today. Although they can be more expensive, they are essential for critical medical diagnostic equipment. The response time of medical equipment can mean the difference between life and death for patients. Medical HDI PCBs guarantee high-speed data transmission, avoiding various response problems. Additionally, this high-density circuit board is resistant to electromagnetic interference and noise, making it ideal for most medical equipment. Most medical CT scanning equipment, as well as multimodal physiology and ECG monitors, can benefit from true floating-point input enabled by the HDI PCB’s high-density connectivity.
Medical flexible printed circuit boards, also known as “medical flex PCBs,” are patterned arrangements of printed circuit components that use flexible-based materials (FPC), with or without flexible substrates. Flexible PCBs are in great demand in the medical electronics industry because they offer unique advantages over traditional PCBs, such as miniaturization, design freedom, and flexibility, to meet the industry’s needs.
Medical electronics must withstand the harsh conditions of the human body while providing high reliability and electrical performance, making flexible circuits ideal for such applications. Often made of thin, flexible materials such as polyimide or polyester, they can be bent, folded, or twisted to fit tight spaces or complex shapes. Furthermore, flex PCBs are designed to withstand temperature changes and are waterproof, sterile, and capable of multiple reassembly.
Several medical devices use flexible circuits as their core, including cardiac pacemakers, defibrillators, neurostimulators, ultrasound machines, endoscopes, and others.
Multilayer Rigid PCB
Both flexible PCBs and rigid PCBs are used in medical devices, but rigid PCBs provide a stronger internal structure for medical devices. The main advantage of rigid PCBs is that they offer a stable platform for electronic components, which are arranged on the PCB. Medical electronics with high precision or complex functions require more components to support their functionality, and thus, the number of layers on the PCB needs to be increased.
We use rigid PCBs in most high-end medical products, such as surgical robots, X-ray machines, MRI equipment, ECG machines, and chemotherapy pumps. Most medical device manufacturers choose multilayer PCBs for such applications. The materials used for these PCBs include glass epoxy resin, aluminum, ceramic, and others.
Strict medical PCB testing
The development process for medical devices includes extra considerations and requirements beyond what is generally required for creating non-critical PCBs. Much testing is conducted on medical equipment, which is more than can be said for other kinds of PCBs. This is primarily because of the stringent testing requirements imposed by regulatory agencies; however, functional testing and production testing are often also necessary. The regulatory testing that is required for medical devices usually falls into one of two broad categories:
- Medical equipment that either transfers energy to or from a patient or detects energy transmitted to or from a patient is the focus of IEC Standard 60601-1.
- Medical equipment not connected directly to a patient, such as that used in a laboratory, falls within the IEC 61010-1
The preceding information showcases FS Technology’s expertise in medical PCB manufacturing and assembly. If you acknowledge our proficiency, please do not hesitate to contact us via email. We will respond to your inquiry promptly and provide you with an affordable PCBA quotation.