Double Sided PCB

Double sided PCB is designed with two sides for component mounting, with copper coating on both the top and bottom layers. The two sides are separated by an insulating material, and they are connected through plated through holes. These holes allow for component connections and soldering. To enable effective circuit creation, proper connection configurations must be established between the two sides. Vias are used to establish bridging connections between the layers. These vias are small holes on the board coated with a metallic layer, facilitating the interconnection of circuits between the two sides. This interconnection capability greatly simplifies the design of complex circuits.

AspectDouble-Sided BoardMultilayer Board
ConstructionConductive traces on both sides of the boardMultiple layers of conductive traces, with internal layers sandwiched between insulating layers
Number of Layers2More than 4
ComplexityLess complexMore complicated
Component DensityModerateHigh
Trace RoutingTraces on both sidesTraces on multiple layers
SizeLargerSmaller
Signal IntegritySusceptible to interferenceGood signal integrity
Manufacturing CostLowHigh
Thermal ManagementLess effectiveGood heat dissipation
ApplicationLow-density designs, Simple circuitsHigh-density designs, Complex circuits

Double Layer PCB Board features

  • Increased circuit density: With two-sided conductive traces provide a larger space for circuitry, allowing for the connection of a greater number of components within a smaller area.
  • Improved signal integrity: By routing signal traces on both sides of the board, double sided PCB can minimize trace lengths, reduce electromagnetic interference (EMI), and enhance overall signal integrity.
  • Enhanced functionality: The structure of double-sided enables the configuration of complex circuits and designs, making it easier to incorporate additional components such as resistors, capacitors, and integrated circuits, thus enhancing the overall functionality of the circuit.
  • Versatile routing options: Vias can be used to establish connections between the upper and lower layers of the board, allowing for efficient routing and improved design flexibility.
  • Cost-effective: Compared to a multilayer PCB, double-sided PCB is generally more cost-effective. The production process requires less material and involves fewer production phases, resulting in lower manufacturing costs.
  • Easy maintenance: If any component or circuit on the board becomes damaged, it can be easily repaired and replaced by the manufacturer. Components can be accessed and desoldered from both sides of the board, simplifying maintenance procedures.
  • Widely available: These boars are easily accessed and can be used in the electronic industry. They also have compatibility with different manufacturing processes making them effective to use in different applications and projects.

Double Sided PCB Board Provided by FS Technology

Double Sided FR4 PCB

This double sided circuit board is a popular choice for various electronic projects. They are constructed using FR4 materials as the substrate, along with prepreg layers to insulate the copper layers. FR4 is an epoxy glass fiber material that offers excellent bonding properties and minimal contraction. These double-sided boards are particularly suitable for projects with complex circuits, as they can accommodate a larger number of traces and connections. Moreover, they are well-suited for applications that involve high temperatures, thanks to their glass transition temperature (Tg) of approximately 135 degrees Celsius. These features make them a preferred choice for electronic projects that require robust and reliable performance.

Double Sided PTFE PCB

PTFE, also known as polytetrafluoroethylene or Teflon, is widely recognized as important material for high-frequency PCB. Double sided PTFE PCB is considered to be better for handling HF signals with minimal signal loss.

The manufacturing process of PTFE boards is similar to that of other double-sided boards. The core layer of the board is made from PTFE material, typically PTFE fiberglass. On top of the core layer, a thin copper layer is applied. This copper layer serves as the conductive surface for creating traces and mounting components.

Double-Sided Metal Core PCB

Metal core boards, also known as thermal PCBs or MCPCBs, are specifically designed to handle high-power components and devices that generate significant heat. The base material of these boards is a metal core, which acts as a heat sink, efficiently dissipating heat and preventing components from overheating and getting damaged.

Typically, copper or aluminum is used as the metal core material due to their excellent thermal conductivity properties. Aluminum is often preferred as it is lightweight and cost-effective compared to copper, which is more expensive.

The construction of metal core boards involves layer stack-up, consisting of a metallic core, a dielectric layer, and copper layers on both sides. The metallic core provides the heat dissipation capability, while the dielectric layer provides electrical insulation. The copper layers are used for circuit traces and component mounting.

One important feature of Double-Sided metal core boards is the use of plated through-hole (PTH) drills on the metallic core. This process allows for the creation of electrical connections between the copper layers, adding complexity and cost to the board compared to single-sided metal core circuit boards.

Double-Sided Ceramic PCB

Due to its fragility, a double layer PCB of ceramic material is difficult to construct, and its structure contains two conductive layers. Alumina (Al2O3) and Aluminum Nitride (AlN) are widely used as ceramic substrates due to their excellent thermal conductivity and low thermal expansion characteristics. These boards offer high electrical insulation and mechanical strength, making them suitable for applications that involve high temperatures.

Although two-layer circuit structures are difficult and expensive to build, they are found in a variety of industries that require temperature control and electrical isolation, such as power electronics, automotive electronics, aerospace, and high-power LED lighting.

Double Sided PCB Manufacturing Process

The manufacturing process of double sided PCB board shares similarities with single sided PCB, but with some key differences:

  • Milling: Since conductive layers need to be generated on both sides of the PCB, a milling process is required to remove the metal layer on one of the boards so that components and circuits can be placed on both sides. When double sided PCB milling, it is necessary to put the board surface into a CNC milling machine and use a rotating tool to remove the unnecessary copper clad layer to expose the underlying substrate.
  • Substrate and Insulation: The substrate material typically consists of fiberglass epoxy resin or similar materials. The substrate provides insulation and serves as the base for the board, offering a balance of rigidity and flexibility.
  • Copper Foil: Laminated copper foil is present on both sides of the substrate material, providing the conductive paths for circuitry and component connections.
  • Solder Mask: Since there are circuits on both sides of the board, solder mask is applied to both sides of the board to protect the conductive traces and prevent solder bridges during assembly. The solder mask is typically applied as a colored layer, providing a protective coating.
 

Additional requirements for double-layer PCB manufacturing include:

  • Drilling and PTH: Double-sided boards require drilling of through holes to establish connections between the top and bottom layers. These holes are then electroplated with copper to create conductive pathways.
  • Insulation and Resin Filling: In the case of double-sided boards with metallic cores or plated through holes (PTHs), additional drilling and resin filling may be needed to insulate and protect these components.
  • Double Surface Mount Technology (SMT) Assembly: Double-sided boards require SMT assembly on both sides, involving the placement of surface-mounted components and soldering them to the respective solder pads.

Heat Dissipation of Double Sided PCB

To prevent double-panel overheating and ensure the proper functioning of electronics, FS Technology recommends implementing the following measures:

  • Heat Dissipation: Utilize heat sinks to dissipate heat effectively from the board and components, preventing overheating and potential damage. Heat sinks help transfer heat away from critical areas.
  • Cooling Solutions: Incorporate fans or other cooling mechanisms to enhance airflow and maintain optimal operating temperatures. Fans can assist in circulating air and preventing heat buildup on the board.
  • High-Quality Components: Use high-quality components known for their thermal stability and durability. These components are less likely to be affected by overheating, ensuring reliable performance and longevity.
  • Optimize Thermal Performance in Board Design: Design the board with thermal considerations in mind. Choose materials with good thermal conductivity properties to enhance heat dissipation. Proper placement of components and traces can also improve thermal performance.
  • Temperature Monitoring: Regularly monitor the temperature of the board during operation. Implement temperature sensors or thermal management systems to track and control the temperature, avoiding excessive heat accumulation.