3.5-Inch Embedded Boards for Industrial Applications
What Is a 3.5-Inch Embedded Board?
The 3.5-inch form factor (146 x 102 mm) is a standardized embedded computing platform that delivers a complete computing core in a compact footprint. These boards integrate the processor, memory, storage interfaces, and extensive I/O on a single board sized to fit space-constrained enclosures while providing the connectivity industrial applications require.
3.5-inch embedded boards occupy the middle ground between ultra-compact SoMs like Qseven and larger form factors like Mini-ITX. They provide more onboard I/O than modular architectures while maintaining a footprint suitable for compact panel PCs, kiosks, and embedded controllers.
Our selection of 3.5-inch boards from Axiomtek and ARBOR Technology provides access to proven industrial platforms with long-term availability, extended temperature support, and the reliability required for continuous operation.
The Power of 3.5-Inch Boards: A Technical Overview
Fanless Operation
Industrial 3.5-inch boards, such as the Axiomtek CAPA series, are designed for fanless operation. By pairing low-power processors with efficient thermal designs, these boards dissipate heat via conduction to external heatsinks or enclosures, eliminating the need for active cooling. Fanless operation eliminates a primary failure point, reduces acoustic noise, and prevents contamination from airborne particulates in factory and outdoor environments.
Extended Temperature Support
Many 3.5-inch boards support operating temperatures from -40°C to +85°C, enabling deployment in outdoor enclosures, vehicle installations, and industrial environments with wide thermal swings. The Axiomtek CAPA322 with Intel Atom x6413E processor is validated for this full industrial temperature range, with soldered memory and processors to ensure reliability under thermal stress.
Rich I/O Connectivity
3.5-inch boards provide extensive onboard connectivity without requiring expansion cards:
- Display outputs: HDMI, DisplayPort, LVDS, eDP, and VGA options supporting triple-display configurations and resolutions up to 4K
- Networking: Dual Gigabit Ethernet standard on most models, with 2.5 GbE available on newer boards like the CAPA322 and CAPA13R
- USB: Multiple USB 3.0/3.2 and USB 2.0 ports for peripherals, storage, and device integration
- Serial: RS-232 and RS-232/422/485 ports for legacy equipment and industrial protocols
- Digital I/O: 8-channel GPIO for sensor integration and discrete control
- Audio: HD audio codec with line-out and mic-in for HMI and kiosk applications
Expansion Options
While 3.5-inch boards provide substantial onboard I/O, they also support expansion for wireless connectivity and specialized interfaces:
- M.2 Key E: Wi-Fi 6 and Bluetooth modules
- M.2 Key B: 5G, LTE, and 4G cellular modems
- Mini PCIe: Legacy wireless cards, additional serial ports, or specialized I/O
- ZIO Connector: Axiomtek's proprietary expansion interface providing additional PCIe, LPC, USB, and SMBus signals for custom I/O modules
Security Features
Industrial applications increasingly require hardware-based security. Many 3.5-inch boards support TPM 2.0 (Trusted Platform Module) for secure boot, disk encryption, and credential storage. Watchdog timers provide automatic recovery from software faults, ensuring system availability in unattended deployments.
Processor Options
3.5-inch embedded boards accommodate Intel processors optimized for low power consumption and extended availability:
Intel Atom x7000RE Series (Amston Lake): The latest generation of Intel Atom processors for IoT and edge computing. The ARBOR EmCORE-iX700 features this processor family with enhanced performance, security features, and power efficiency for real-time applications, including object tracking, defect detection, and traffic monitoring.
Intel Atom x6000E Series (Elkhart Lake): Industrial-focused processors with enhanced I/O and security. The Axiomtek CAPA322 supports the Atom x6413E with full industrial temperature range and up to 32GB DDR4 memory.
Intel Atom x5/x7 E3900 Series (Apollo Lake): Proven quad-core processors balancing performance and power consumption. The Axiomtek CAPA310 and CAPA311 feature the Atom x5-E3940 with extended temperature support (-40°C to +80°C).
Intel Pentium N4200 / Celeron N3350: Mid-range processors providing additional performance headroom for applications requiring more processing capability than Atom while maintaining fanless thermal budgets. The Axiomtek CAPA312 and CAPA313 support these processors.
Intel Celeron J6412 / N6210: Current-generation Celeron processors with improved graphics and I/O performance. The CAPA322 supports these processors for applications requiring enhanced display and networking capabilities.
Applications
3.5-inch embedded boards power compact systems across industrial and commercial applications:
Industrial Automation: Compact controllers, machine interfaces, and edge gateways for factory automation and process control. The small footprint fits control cabinets and equipment enclosures where space is constrained.
Human-Machine Interface (HMI): Touch panel controllers and operator stations requiring multi-display support, industrial temperature operation, and long-term component availability.
Digital Signage: Media players and information displays that require fanless operation, reliable 24/7 playback, and multiple video outputs for single- or multi-screen configurations.
Kiosks and Self-Service Terminals: Interactive kiosks, point-of-sale systems, and ticketing terminals requiring compact computing with rich peripheral connectivity.
Medical Devices: Diagnostic equipment, patient monitoring, and clinical workstations where regulatory compliance demands long-term component availability and proven reliability.
Transportation: Passenger information displays, fare collection systems, and in-vehicle computing that require vibration resistance and wide-temperature operation.
IoT Gateways: Protocol conversion, data aggregation, and edge processing for Industrial IoT deployments. For more advanced edge computing with AI acceleration, explore our edge AI computers.
Comparing 3.5-Inch Boards to Other Form Factors
| Specification |
3.5-Inch |
Qseven |
Mini-ITX |
| Dimensions |
146 x 102 mm |
70 x 70 mm |
170 x 170 mm |
| Architecture |
Complete SBC |
Module + Carrier |
Complete SBC |
| Onboard I/O |
Extensive |
Via carrier board |
Extensive + expansion slot |
| PCIe Expansion |
Mini PCIe / M.2 |
Via carrier board |
Full PCIe slot |
| Best For |
Compact systems with standard I/O |
Custom I/O, upgradeable CPU |
Systems requiring add-in cards |
Choose 3.5-inch boards when your application requires a complete, ready-to-integrate computing platform with rich onboard I/O in a compact footprint. For applications requiring custom I/O configurations or CPU upgrade paths, consider Qseven or SMARC modules. For applications that require PCIe expansion cards, consider Mini-ITX motherboards.
Your Strategic Partner in Embedded Computing
Westward Sales is more than a supplier; we are your strategic partner in embedded computing. We understand that 3.5-inch embedded boards represent an optimal balance of compact design, powerful performance, and industrial-grade reliability for space-constrained applications.
Our commitment to long-term product availability, spanning up to 7 years on many models, protects your investment in system design and certification. By choosing our 3.5-inch boards, you gain access to proven platforms that accelerate time-to-market while ensuring a consistent supply throughout your product's lifecycle.
Explore our full range of 3.5-inch embedded boards, compare features across the Axiomtek CAPA series and ARBOR EmCORE platforms, and contact our team to find the ideal board for your next project.
