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Why Do Hearing Aids Device Use a PCB?

Printed Circuit Boards (PCBs) are used in the medical industry because of the flexible wiring prospects they offer. Today, you can use these boards in hearing aids devices. The reasons for this are discussed in this article.

What are Hearing Aids Devices?

These are dedicated devices for boosting the audio signal reception for people with difficulty in hearing. These high-tech devices are capable of improving the audio signal transmission, as well as improving the listeners’ speech understanding.

Challenges Addressed by PCB’s Usage in Medical Electronics

It is noteworthy to mention that Printed Circuit Boards (PCBs) are now popularly used in the global medical industry because of the innovations they bring.

From the miniaturization capabilities to reducing costs; these boards can provide a wide range of improvements for medical devices.

Some of the persistent challenges that are addressed are thus:


Considering that most medical devices and wearables (such as hearing aids) are exposed to dangerous environments – they need to be reliable.

PCBs have proven to be a reliable technological improvement that allow for the devices to function optimally. Ideally, your hearing aids device made with a PCB should be able to withstand exposure to extreme temperature and shocks.

Classes and Compliances

Due to the disparities of medical electronics, there is a need to choose PCBs based on their classes. For example, the Class 3 medical devices require more precision. As such, it is expected that the circuit boards must meet the following conditions:

  • Process qualification standards
  • Installation qualification standards and;
  • Operation qualification standards

Miniature Construction

The best hearing aids device uses a PCB that doesn’t taken up much space. This is why the flexible circuit boards are a popular choice.

Generally, the choice of a PCB for medical electronics/devices should be based on the minimal size. This allows for the board’s fitting into the compact spacing on the device.

Flexible PCBs: The Best Circuit Boards for Hearing Aids Devices?

Hearing Aids Device PCB
Hearing Aids Device PCB

The flexibility of this type of PCB makes it a popular choice not just for hearing aids devices, but for most medical devices.

Flexible PCBs, as the name suggests, are flexible circuit boards. The flexible modifications support the wrapping folding or bending of the medical devices.

Besides, when these boards are used in the hearing aids devices, they help to coordinate the entire wirings in a compact footprint.

Circuit Diagram of Hearing Aids Device

Wondering what is inside a hearing aids device? Beyond the hook that fits behind the ear, the device also has a microphone and a couple of other components.

Here is a breakdown of the different, important parts usually found inside the device:

1. The Microphone

This is one of the most important parts, as it deals with the picking up of sounds from the environment. This would then be converted to an electrical signal for further analysis and adjustments, based on the listener’s degree of hearing loss. The digital code or electrical signal can further be optimized based on the immediate environment where the listener is.

2. The Flex PCB

You can also find the flexible Printed Circuit Board (PCB) inside the device. Among many other functions, the board helps to coordinate most of the other components and wires inside the hearing aid.

It also comprises a mixture of Integrated Circuits (ICs) and a wide range of other components.

3. The Battery

The hearing aids device needs to have a source of power and that is what the battery is used for.

4. The Receiver

The receiver is a component that sees to the conversion of the amplified electrical signal into the corresponding sound. This sound would then be delivered into the listener’s ear.

5. The Antenna

The radio uses the antenna for radio frequency signal reception and transmission. We can help you optimize the antenna to fit into the hearing aid’s shape and possibly tune it up to 2.4 GHz.

Why Flexible PCBs are Popular in Hearing Aids Devices

Flexible circuit boards are a popular choice for manufacturing hearing aids device because of the following reasons:

1. Miniaturization

Due to the need to reduce the size of most medical devices; it is expedient to use components that make that possible.

With flexibility and the ability to fit into smaller footprints; flexible PCBs make this possible. Thus, you can bend or wrap the boards in whatever direction and they will still perform the desired function in the device.

2. Used in Place of Wiring

These boards are commonly used in place of plug connections and wiring. This is an improvement geared towards the reduction of excessive wires in the hearing aids device.

Besides, the replacement of wires and plugs allow the flex PCBs to provide a combination of utmost reliability and flexible designs.

3. Flexible Installation Options

Have you ever manufactured a device and realized that one feature or more is missing? At times, it could be a herculean task to get those things fixed.

However, you could do better with the flexible installation options that come with flexible circuit boards.

Coupled with the high miniaturization level; it is possible to integrate new components and functions, without necessarily increasing the device’s size.

4. HDI Capabilities


The High-Density Interconnect (HDI) capabilities also make the flexible PCBs a better choice for medical wearables.

The following are some of the things you need to know about the HDI capabilities:

  • Multiple Interconnects: the HDI flex circuit boards allow for multiple interconnections to be made. The interesting thing is that all these interconnections can be made without expanding the device’s current space.
  • Versatility in Routing: the routing paths are versatile, thus, offering different ways to make the interconnections.
  • Affordability: in addition to interconnecting multiple components, the HDI flex PCBs are also affordable. When comparing a 6-layer HDI flex PCB to an 8-layer rigid PCB; the former costs less.
  • Reduce Space Requirements: HDI flexible PCBs support several interconnections even within a compact footprint. However, the space requirements are further reduced because of the presence or integration of micro, buried and blind vias.
  • Signal Integrity: the reliability and integrity of the signal is further improved due to the proximity of the components.

5. Improved Reliability

You can rely on hearing aids devices made with flexible PCBs to be highly-reliable. The reliability of the hearing aid circuit board is because of the following reasons:

  • Resistance: most flexible circuit boards are made of polyimide materials, which make the boards resistant to chemical changes, and extreme temperature exposures.
  • Minimized Connection Points: as the connection points and routing paths are knit; it is almost impossible for the hearing aids device to suffer from poor solder joints.
  • Electrical-Reliability: the electrical-reliability of the flexible PCBs also makes it ideal for use with hearing aids devices. Features like the uniform spacings and trace widths, improved dielectric constant and uniform material thickness make this possible.

6. Bending Ability

The flexibility of these circuit boards is another boost to the hearing aids devices’ function. Since flexibility is becoming a requirement for most medical devices and wearables; it makes sense to use a flexible PCB for the purpose.

Here are some of the advantages to the board’s flexibility:

  • It helps to contain the contraction and expansion of medical devices like hearing aids devices, especially during the operations.
  • The bending, folding and twisting allow for the creation of connections that could have hitherto, not been possible with the rigid Printed Circuit Boards (PCBs).

Flex and Rigid PCBs for Hearing Aids Device: Which is Better?

Both the flexible and the rigid circuit boards can be used to optimize the performance of medical devices and wearables.

However, when it comes to the hearing aids device, the flex PCBs are a popular choice. Here is how it compares to the rigid circuit boards:

Multi-Shape Formation

Flexible circuit boards can be formed into complex shapes, especially in Three Dimensions (3D). This also comes with the creation of branches to multiple connectors.

Flexibility Options

The fact that most medical devices, especially hearing aids devices have limited spaces make the flex PCBs ideal for them. The flexible folding and twisting make the board easy to fit into any of the available spaces on the target devices.

However, the integration of flexible and rigid-flexible circuit boards could also boost the hearing aids device performance. Here are some of the advantages:

Combined Functions

The rigid-flex PCBs combine the flexibility of the flex circuit boards with the durability of the rigid circuits. This is why most hearing aids devices made with this combined PCB architecture can be both flexible and durable.

Design Versatility

One advantage of the flexible PCBs is the smaller size, which also translates to less weight. However, the rigid PCBs can weigh more.

The combination of the rigid and flexible circuit boards in one footprint allows for the durability to be profound, without the size and weight of the rigid PCBs being noticed.


Using flexible circuit boards in a hearing aids device is a sure way to sound reception and decoding easier for people with difficulty with hearing. If you want to add more flexibility, consider going for the rigid-flex PCBs that add more durability, without integrating much of the rigid PCBs’ weight and size.




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