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Cavity Substrate| Package substrate Manufacturer, RF Cavity PCBs, Antenna Cavity PCBs, We offer Cavity PCBs from 4 layer to 50 layers, To use the High frequency and high speed materials, or materials of their type.

The rapid development of electronic equipment has given rise to the continuous advancement of PCB (Printed Circuit Board) technology. As an important innovation in the field of PCB design and manufacturing, Cavity Substrate (grooved substrate) technology is gradually becoming a hot topic in various industries. Cavity substrates accommodate electronic components by embedding grooves or cavities in the substrate, thereby improving circuit integration and performance. This technology not only excels in high-frequency and high-density applications, but also brings huge innovation potential to fields such as wireless communications, medical devices, automotive electronics, and aerospace. With the increasing demand, the application prospects of cavity substrates are becoming more and more broad.

What is Cavity Substrate?

A cavity substrate is a specific type of printed circuit board (PCB) that is unique in having recessed areas (i.e., cavities) inside or on the surface that are used to mount various electronic components. This design not only enables higher integration, but also makes the circuit design more compact, thereby saving space and improving overall circuit performance.

The emergence of cavity substrates is in response to the increasing miniaturization and high-performance needs of modern electronic devices. Traditional planar PCBs are no longer able to meet the requirements of some specific applications, especially when a high degree of integration and small size are required. For example, in modern electronic products such as mobile phones, laptops, and wearable devices, cavity substrates can effectively save space and improve product functionality.

Cavity substrates are particularly common in microwave and RF circuits. The reason is that these circuits have very high requirements for signal integrity, and any small signal loss or interference may lead to a significant decrease in performance. The cavity substrate can effectively shield external interference and reduce signal loss during transmission by embedding electronic components in the recessed area. Specifically, the cavity substrate shows significant advantages in the following aspects:

Reduce parasitic capacitance and inductance:Components on traditional PCBs will produce parasitic capacitance and inductance between each other, affecting the quality of signal transmission. Cavity substrates reduce these parasitic effects by embedding components within the cavity, thereby improving circuit performance.

Improve thermal management capabilities:The design of the cavity substrate facilitates better heat dissipation, especially in high-power applications. The recessed cavity can be filled with thermally conductive materials to enhance the heat conduction effect and ensure that electronic components maintain a stable temperature during operation.

Enhance mechanical strength:The cavity substrate improves the mechanical strength and shock resistance of the circuit by embedding components inside the substrate. This is especially important in mobile devices and other applications that require frequent movement or vibration.

Optimize signal path:Cavity substrates allow designers more freedom to optimize signal transmission paths and reduce signal delays and losses. This is critical for high-speed data transmission and high-frequency applications.

The manufacturing of cavity substrates involves complex processes, including high-precision etching and laser processing techniques. These processes ensure the precise size and shape of the cavity to meet stringent design requirements. At the same time, the material selection of the cavity substrate is also very critical. Commonly used materials include FR-4, ceramics and high-frequency copper-clad laminates, etc., depending on specific application requirements.

To sum up, the cavity substrate, as an advanced PCB technology, provides higher integration, better signal performance and better thermal management capabilities through a unique recessed design, and is widely used in high-frequency, high-frequency power and highly integrated electronic devices. Today, with the rapid development of electronic technology, cavity substrates undoubtedly provide strong support for the design and manufacture of more efficient and compact electronic products.

Buried type cavity PCBs
Buried type cavity PCBs

Cavity Substrate design Reference Guide.

When designing a cavity substrate, several key factors need to be considered to ensure the performance and reliability of the final product. The following are several important aspects that must be paid attention to during the design process:

Cavity depth and dimensions

The depth and size of the cavity substrate are one of the core parameters of the design. First, the depth and dimensions of the cavity need to be determined based on the size and functional requirements of the installed components. For example, high-frequency components and sensitive components may require specific depths and dimensions to avoid electromagnetic interference and heat build-up. At the same time, the design of the cavity also needs to consider the feasibility and cost-effectiveness of the manufacturing process. A cavity that is too deep or too small may increase processing difficulty and cost. Therefore, the cavity size should be designed reasonably while meeting functional requirements.

Material selection

The material selection of the cavity substrate directly affects its mechanical strength and electrical properties. Common substrate materials include FR-4, ceramics and high-frequency materials. FR-4 is a commonly used glass fiber reinforced epoxy resin with good mechanical and electrical properties and is suitable for most general electronic products. Ceramic materials are suitable for high frequency and high temperature applications, with excellent thermal conductivity and low dielectric losses. In addition, for specific applications, high-frequency materials with specific electrical properties need to be selected to meet signal transmission requirements. Material selection should be based on application requirements, balancing factors such as performance, cost and manufacturing processes.

Thermal management

As the power density of electronic components continues to increase, thermal management becomes a critical issue in design. The design of the cavity substrate needs to consider effective heat dissipation strategies to avoid performance degradation and reliability issues caused by heat accumulation. The heat dissipation performance can be improved by optimizing the cavity layout, using high thermal conductivity materials, and designing heat dissipation channels. In addition, auxiliary heat dissipation measures such as thermal pads and heat sinks can be used to further enhance the thermal management effect. Reasonable thermal management design can extend the service life of electronic products and improve their working stability.

Signal integrity

In high-frequency and high-speed circuit design, signal integrity is a key factor in ensuring circuit stability and performance. The cavity substrate design needs to consider issues such as signal transmission paths, impedance matching, and electromagnetic interference. By optimizing signal routing, designing a reasonable stack structure, and adding shielding layers, signal integrity can be effectively improved. In addition, avoiding long traces and excessive via design is also an important means to improve signal quality. For high-frequency signals, special attention must be paid to the electromagnetic environment around the cavity to reduce interference and signal loss.

In summary, designing a cavity substrate requires comprehensive consideration of multiple key factors such as cavity depth and size, material selection, thermal management, and signal integrity. By comprehensively optimizing these design elements, a high-performance, high-reliability cavity substrate can be achieved to meet the needs of modern electronic products for high integration and high performance.

What material is used in Cavity Substrate?

As a special type of printed circuit board (PCB), cavity substrates usually use a variety of materials in their manufacturing process to meet the needs of different application scenarios.

FR-4 (fiberglass reinforced epoxy resin)

FR-4 is a widely used substrate material whose main components are fiberglass and epoxy resin. This material has excellent mechanical strength and electrical properties, providing stable performance under normal temperature and humidity conditions. Due to its relative affordability and ease of processing, FR-4 is often used in cavity substrate manufacturing where general performance requirements are less stringent.

Ceramic material

For high-frequency and high-temperature applications, ceramic materials are often used for the cavity substrate. Ceramics have excellent thermal conductivity and low dielectric losses, enabling stable performance in extreme environments. Common ceramic materials include Alumina and Silicon Nitride. These materials can meet application scenarios with high requirements on frequency response and signal stability, such as wireless communications and radar systems.


Copper is the main conductive material in the cavity substrate and is often used as the conductive layer. Copper has excellent electrical conductivity and processability, and can provide stable and reliable electrical connections. During the manufacturing process of cavity substrates, copper is usually plated on the surface of the substrate and formed into circuit patterns through chemical etching or mechanical processing. Its advantages include good electrical conductivity, good solderability, and good compatibility with other materials.

By rationally selecting and combining these materials, cavity substrates can achieve excellent performance in different application scenarios, thereby promoting technological development and innovation in wireless communications, medical electronics, aerospace and other fields.

What size are Cavity Substrate?

The size of the cavity substrate is critical to the design of electronic devices because it directly affects component layout, circuit complexity, and overall performance. The dimensions of the cavity substrate usually vary according to specific application requirements, so comprehensive consideration and optimization are required during the design process.

Designers typically determine the length, width, and thickness of the cavity substrate based on the size of the required components and the complexity of the circuit. The first thing to consider is the size and layout of the components to ensure they fit into the space inside the cavity and can be easily arranged and connected. For large components or circuits that require more spacing, a larger cavity substrate may be required to provide sufficient mounting space and wiring area.

Secondly, the complexity of the circuit will also affect the determination of the cavity substrate size. For circuits containing multiple functional modules or complex signal processing, a larger substrate size is usually required to accommodate more components and connections. In addition, considering signal transmission paths and interference issues, designers may need to reserve enough space inside the cavity to ensure signal integrity and stability.

In addition to length and width, the thickness of the cavity substrate is also one of the important factors to consider. The choice of thickness not only affects the mechanical strength and structural stability of the substrate, but also affects the performance of thermal management and signal transmission. For high-power or high-frequency applications, designers may choose a thicker substrate to provide better heat dissipation and signal isolation.

To sum up, the size design of the cavity substrate is a complex and critical process that requires full consideration of component layout, circuit complexity, signal integrity, thermal management and other factors. Through reasonable size design, optimized layout, performance improvement and innovative design of electronic equipment can be achieved.

The Manufacturer Process of Cavity Substrate.

The manufacturing process of cavity substrates requires a series of precise steps to ensure stable performance and reliable quality of the final product. Below is a detailed description of each step:

Design and Drawing

In the initial stage of cavity substrate manufacturing, engineers use professional design software to draw circuit diagrams and cavity structures. This stage requires taking into account the functional requirements of the circuit as well as the size and shape of the cavity. Through CAD software, engineers can accurately determine the circuit connection method and cavity layout, providing accurate design guidance for subsequent manufacturing steps.

Material preparation

After the design is completed, the manufacturing process enters the material preparation stage. According to the design requirements, select the appropriate substrate material and perform necessary pretreatment. Commonly used substrate materials include FR-4 fiberglass reinforced epoxy resin and ceramic materials. The quality and accuracy of material preparation are critical to the performance and stability of the final product.

Pattern transfer

Pattern transfer is a critical step in transferring circuit patterns to the substrate surface. This is usually achieved through photolithography or screen printing techniques. In this process, photoresist or ink is applied to the surface of a substrate, and a template or mask is then used to transfer the pattern onto the substrate. The accuracy of pattern transfer directly affects the accuracy and efficiency of subsequent steps.


Etching is the step of removing excess conductive material to form the desired circuit pattern. This is usually achieved through chemical etching or mechanical processing. In chemical etching, the substrate is immersed in a corrosive solution that dissolves away portions of the conductive material not covered by photoresist or ink. In machining, precision processing equipment is used to remove excess material. Precise control and high efficiency of the etching process are key to ensuring circuit quality and stability.

Drilling and plating

After etching is complete, holes need to be drilled into the substrate and electroplating is performed to connect the multi-layer circuits. The drilling process requires high-precision drilling equipment to ensure the accuracy of hole diameter and location. The electroplating process is to coat a layer of conductive material on the hole wall to facilitate subsequent connections between circuit layers.

Cavity processing

Cavity processing is to form a cavity structure to accommodate electronic components and achieve higher integration. This is usually achieved through laser cutting or machining techniques. According to the design requirements, engineers precisely cut or process the substrate to form the required cavity structure.

Assembly and testing

The final step is to mount the electronic components onto the cavity substrate and carry out functional testing and quality inspection. During the assembly process, engineers need to accurately install various components and weld or connect them according to design requirements. After completing the assembly, perform functional testing to ensure the normal operation of the circuit. At the same time, quality inspections are carried out to ensure that products comply with relevant standards and regulations.

The Application area of Cavity Substrate.

Cavity substrate is a key technology widely used in electronic devices. Its excellent performance and flexible design make it play an important role in many fields.

Wireless communication equipment

In the field of wireless communication equipment, such as mobile phones, routers, etc., cavity substrates are widely used. Due to the increasing demand for high-frequency performance and compact designs in these devices, cavity substrates are able to provide excellent signal transmission performance while enabling compact circuit layouts. By installing and packaging key components inside the cavity, signal interference can be effectively reduced and communication quality and stability improved.

Medical equipment

In the field of medical devices, cavity substrates play a key role in implantable medical devices. Implantable medical devices have extremely high requirements for device reliability and miniaturization, and cavity substrates can meet these needs. By adopting a cavity structure, electronic components can be compactly integrated inside the medical device while providing good protection and isolation effects to ensure that the device works stably and reliably in the in vivo environment.

Vehicle electronics

In the field of automotive electronics, cavity substrates are widely used in automotive control systems and sensor modules. Automotive electronic equipment requires high temperature resistance and high reliability, and cavity substrates can provide excellent heat resistance and structural stability. By installing and encapsulating key electronic components inside the cavity, they can be effectively protected from environmental factors such as vehicle vibration, humidity, and high temperature, thereby ensuring long-term stable operation of automotive electronic equipment.


In the aerospace field, cavity substrates are widely used in satellites and spacecraft. Aerospace equipment has extremely high requirements for high durability and stability of the equipment, and cavity substrates can provide excellent structural stability and electrical performance. By installing and encapsulating key electronic components inside the cavity, it can effectively protect it from the extreme environmental effects during spacecraft launch, while ensuring its long-term reliable operation in space.

To sum up, cavity substrates play an irreplaceable and important role in the fields of wireless communications, medical care, automobiles, aerospace and other fields, providing key support for the performance improvement and innovation of electronic devices. With the continuous advancement of technology and the continuous expansion of application fields, cavity substrates will continue to play an increasingly important role.

What are the advantages of Cavity Substrate?

As a special type of PCB, cavity substrate shows unique advantages in modern electronic equipment. Its main advantages include:

High integration

A special feature of the cavity substrate design is the recessed area within or on its surface, which provides additional space for the mounting of electronic components. This means that more components can be accommodated within a relatively small physical size, allowing for a higher level of integration. This advantage is particularly significant for volume-constrained applications, such as mobile devices or drones.

Excellent electrical properties

The cavity substrate design can effectively reduce signal loss and electromagnetic interference. Because the spacing between components is smaller and signal transmission paths are shorter, circuit stability and performance are more reliable. Especially in high-frequency and RF circuits, signal integrity is critical to system performance, and cavity substrates can provide a more reliable signal transmission environment.

Better thermal management

The optimized cavity design can effectively improve the heat dissipation effect. In high power density electronic equipment, such as servers or power amplifiers, thermal management is critical. Cavity substrates help to efficiently conduct and dissipate heat away from components by providing a larger surface area for heat dissipation and better air circulation, thus maintaining system stability and reliability.

High mechanical strength

The structural design of the cavity substrate gives it better mechanical strength and durability. Compared to traditional single- or double-layer PCBs, cavity substrates typically have a stronger structure and can withstand greater mechanical stress and vibration. This property makes cavity substrates particularly suitable for applications operating in harsh environmental conditions, such as automotive electronics or aerospace equipment.

In summary, cavity substrates provide important technical support and development space for the design and manufacturing of modern electronic devices through their high integration, excellent electrical properties, good thermal management, and excellent mechanical strength. As the performance and volume requirements for electronic products continue to increase, cavity substrate technology will play an important role in more fields and push the electronics industry to a higher level.


What is the cost of the cavity substrate?

The cost of the cavity substrate is slightly higher than that of the traditional printed circuit board (PCB). This is mainly because the design and manufacturing process of the cavity substrate requires more processes and precision equipment. However, the cost is acceptable given the performance advantages that cavity substrates can provide, especially in high-frequency and RF circuit applications. In some fields with higher performance requirements, such as communications, medical and military fields, the performance advantages of the cavity substrate can often offset its slightly higher cost, so it has a good price/performance ratio.

Can cavity substrates be used in high-frequency circuits?

Yes, cavity substrates are particularly suitable for high frequency and RF circuits. Since the recessed area inside or on the surface of the cavity substrate can effectively reduce the signal transmission path, reduce signal loss and interference, it can significantly improve the performance and stability of high-frequency circuits. This makes cavity substrates ideal for use in wireless communications, radar systems, satellite communications, and more.

Is it difficult to process the cavity substrate?

The processing requirements of the cavity substrate are high and require precise manufacturing equipment and processes. Especially in the processing of cavity structures, advanced laser cutting or precision machining technology is usually required to ensure that the size and shape of the cavity meet the design requirements. However, with the continuous advancement of manufacturing technology, the difficulty of processing is gradually reduced, and production efficiency and processing accuracy are also constantly improving. Therefore, although the processing of cavity substrates is relatively complex, high-quality production can still be achieved with the support of professional manufacturers.



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