RIGID PCB
WHAT IS A RIGID PCB CIRCUIT BOARD?
A Rigid PCB, or Printed Circuit Board, consists of a hard, inflexible substrate that supports and electrically connects electronic components through etched copper pathways. This solid framework, often made from FR-4 material, provides a durable base that does not bend or warp, ensuring the components remain securely in place and maintain consistent performance. The structure of rigid PCBs makes them ideal for a wide range of applications where stability is crucial.
The primary role of a rigid PCB is to provide a reliable platform for mounting various electronic components, facilitating electrical connections between them. By doing so, it forms the operational backbone of electronic devices, enabling functionalities from simple to complex systems. The rigid PCB’s robust construction supports advanced circuit designs, including multi-layer configurations, enhancing device performance while adhering to compactness and efficiency requirements.
RIGID PCB EXAMPLES
CHARACTERISTICS OF RIGID PCB
High Mechanical Strength
Rigid PCBs boast high mechanical strength due to their solid substrate, which ensures the board withstands pressure and impact, making it suitable for robust applications.
Cost-effectiveness for High Volume Production
For mass production, rigid PCBs are cost-effective due to their ease of manufacturing and assembly. Their standardization and compatibility with automated assembly processes reduce overall production costs.
Multi-layer Configurations
Rigid PCBs can accommodate multi-layer designs, allowing for more complex circuits in a compact space. This feature is critical for advanced electronic devices that require numerous connections and functionalities within limited physical dimensions.
Dimensional Stability
Unlike flexible PCBs, rigid PCBs maintain their shape and dimensions over time, ensuring that component alignment and functionality remain unaffected by environmental factors.
Durability and Stability
Rigid PCBs are known for their exceptional durability and stability. The solid substrate material, typically FR-4, ensures the board remains flat and rigid, preventing warping and maintaining the integrity of electronic connections under various conditions.
Effective Heat Dissipation
Their structure is conducive to better heat dissipation compared to their flexible counterparts. The materials used, such as FR-4, have inherent properties that help dissipate heat effectively, which is crucial for maintaining performance and longevity of electronic components.
HOW ARE RIGID PCB BOARDS MANUFACTURED?
RIGID PCB EXAMPLES
PCBs are composed of a substrate, typically FR4, fiberglass, or aluminum, laminated with copper. They may vary in thickness from 0.4mm to 3.5mm and feature a strategic layer stack of copper and insulation to mitigate noise and impedance, solidified with adhesive and heat.
Rigid PCB stack up and materials for manufacturing
Substrate Layer: The substrate layer, primarily made of FR4 fiberglass, forms the core, offering essential rigidity and stiffness. Alternative materials like phenolics and epoxies provide a cost-effective but lower-quality option, susceptible to delamination under prolonged soldering.
Copper Layer: This layer, applied atop the substrate using heat and adhesive, features copper foil that varies in thickness, measured in ounces per square foot. While premium boards have copper on both sides, more economical versions might only use one.
Solder Mask Layer: Positioned over the copper layer, the solder mask provides insulation, protecting against accidental contact with conductive materials, thereby preventing potential short circuits and damage.
Silkscreen Layer: The silkscreen, applied above the solder mask, adds informative characters or symbols in various colors, including white, grey, red, black, and yellow, aiding in board identification and component placement.
RIGID PCB TYPES
Single-sided:Single-sided PCBs represent the genesis of circuit board design, characterized by a sole layer of conductive material with components mounted on just one face. This simplicity in design streamlines the manufacturing process, enhancing efficiency and reducing the likelihood of production errors, offering an economical solution for projects with minimal circuit density requirements.
Double-sided:In contrast, double-sided PCBs expand on this by incorporating conductive copper layers on both their surfaces, effectively doubling the area available for component placement. This feature grants greater flexibility in design and the ability to support more intricate circuits, making them suitable for a diverse array of applications.
Multilayer: Multilayer PCBs further complexify the design by integrating three or more conductive layers, interspersed with insulating material, within the board’s core. This sophisticated structure minimizes the necessity for external wiring, conserves space, and enhances the board’s overall density and durability, accommodating the demands of more complex electronic systems.
Carrier board or Mechanical Spacer:For scenarios necessitating additional support during assembly, particularly with very thin PCBs, a carrier board or mechanical spacer is employed. This structure, devoid of conductive layers, serves as a sturdy foundation to facilitate the assembly process, tailored to meet precise specifications without fulfilling any electrical function, thus ensuring the integrity and support of all mounted components and devices.
RIGID PCB CAPABILITIES
Features
Capabilities
Quality Management Systems
ISO 9001:2015, ISO 13485:2016, and AS 9100 Rev D, UL Certified, RoHS Compliant
Types
Single sided, Double sided, multilayer printed circuit boards, Blind Vias, Buried Vias, Controlled Impedance
Material
Standard FR4: TG135, High TG FR4, TG170 and TG 180, Rogers, PTFE, Aluminum, Copper base.
PCB layers
Up to 64 layers.
Inspection method
Visual, Fly Probe testing and functional testing
Fabrication highlights
Routed arrays, Edge plating, bevels, heat sinks
Surface finishes
HASL, Lead Free HASL, OSP, ENIG, Immersion Silver, Hard Gold, Immersion tin
Min Trace and Space
.003” (.076 mm)
Maxmimum dimensions
21” x 29” (53 x 74 cm)
Minimum mechanical drill
.0059” (.150 mm)
Minimum laser drill
.004″ (.102 mm)
Build time
7-20 days
RFQ
1-2 days
THE DIFFERENCES BETWEEN RIGID PCB AND FLEXIBLE PCB
Rigid PCBs are constructed with a non-conductive substrate, typically glass-reinforced (like FR4), providing structural integrity and thickness. They feature conducting tracks for electrical connectivity, relying on a solid, inflexible base to support and connect components. This design ensures durability but limits flexibility, making them suitable for static applications where the form factor does not change.
In contrast, flexible PCBs use a flexible base material, such as Polyamide, allowing them to bend and fold to fit into compact or irregular spaces. Their conductive paths are made from flexible hard copper, accommodating bending without damage. The manufacturing process of flex PCBs employs the Overlay method, offering protection to the circuits and enhancing durability against environmental factors, including vibration and heat dissipation, making them lighter and more adaptable to complex designs than their rigid counterparts.
WHEN TO USE RIGID AND WHEN TO USE FLEXIBLE
Rigid PCBs are favored in scenarios where cost efficiency and structural stability are paramount. Their lower production cost, coupled with the ability to provide substantial mechanical support, makes them a go-to for a broad range of electronic devices like computers, TVs, and toys. These boards are ideal for applications with sufficient space and where the design does not require the PCB to flex, ensuring reliability and durability in static environments.
Flexible PCBs, on the other hand, are selected for their versatility in high-performance and compact devices such as smartphones, cameras, and wearables. They accommodate tight spaces and complex shapes by offering the ability to bend and fold, potentially reducing the overall cost of ownership by eliminating the need for additional components like connectors and wire harnesses. Flex circuits are also used in simpler applications, like LED lighting, where their flexibility simplifies installation.
RIGID PCB APPLICATIONS
Industrial Electronics: Utilized in robotics, pick and place equipment, enhancing automation and efficiency.
Medical Equipment: Critical in EMG machines, MRI systems, supporting advanced diagnostic and therapeutic technologies.
Automotive: Integral to AC/DC power converters, electronic computer units, transmission sensors, ensuring vehicle performance and safety.
Computing: The backbone of motherboards, enabling the core functionality of computers and laptops.
Telecommunications: Essential for mobile phones, tablets, and signal transmission devices, facilitating global communication.
Aerospace: Employed in cockpit instrumentation, temperature sensors, and control tower equipment, crucial for flight operations and safety.
FAQ
Cost-effective, durable, high-quality, dense configurations, reduced electronic noise, stability under movement, ease of repair and diagnostics, wide application in electronics.
limited design flexibility, inability to fold or bend which restricts use in compact or unconventional spaces, and potentially higher costs and complexity in multi-layer configurations.
A PWB (Printed Wiring Board) focuses on the electrical wiring and layout, while a PCB (Printed Circuit Board) includes the wiring, layout, and electronic components mounted on it.
Copper is used in PCBs for its excellent electrical conductivity, thermal conductivity, and flexibility, enabling efficient signal transmission and heat dissipation.
