Project Background
Our client is a prominent industrial automation company based in Western Europe, with over thirty years of experience in developing precision control systems for factory automation. Their product range includes programmable logic controllers (PLCs), distributed control systems, and specialized industrial control modules widely used in sectors such as automotive, food processing, and pharmaceuticals.
As their customer base grew and demand increased for cost-optimized, application-specific solutions, the company faced a critical bottleneck: their existing PLC-based control architecture was struggling with cost and performance limitations in high-volume manufacturing environments. While off-the-shelf PLCs had been effective for low-volume custom projects, they were no longer suitable for scaled applications.
Although the company housed a skilled engineering team, their expertise was primarily in control logic programming, system integration, and field applications—not in PCB design or manufacturing. Developing in-house PCB capabilities would have required significant investment in specialized equipment, cleanroom facilities, and quality systems. Recognizing this, they turned to a specialized PCB manufacturer to accelerate time-to-market and ensure production reliability, rather than building these capabilities internally.
Client’s Challenges
Cost Inefficiencies at Scale
The client’s primary pain point was unit economics. Standard PLCs typically cost €350–€450 per unit in single-piece or low-volume configurations. When their customers needed large production runs—often 5,000 to 50,000+ units annually—the per-unit PLC cost remained fixed or dropped only marginally. For their end-customers operating on thin margins in competitive markets (such as food packaging lines or automotive assembly), every €50–€100 in controller cost was significant.
A typical deployment involved stacking multiple I/O modules, power supplies, and communication interfaces to meet specific application requirements. This modular approach introduced unnecessary redundancy; customers paid for features and I/O capacity they didn’t use. The client recognized this mismatch: their most frequent customer inquiries centered around reducing controller costs without sacrificing reliability.
Performance and Customization Constraints
Standard PLCs impose architectural constraints. The fixed CPU clock speed, memory configuration, and I/O module interfaces are optimized for general-purpose industrial control but rarely perfect for specialized applications. The client’s customers often required:
- Optimized signal conditioning for high-noise factory environments
- Specialized analog-to-digital conversion (ADC) with 16-bit precision for measurement-intensive processes
- High-speed digital I/O for synchronizing multiple equipment simultaneously
- Custom communication protocols beyond standard Modbus or EtherCAT
Retrofitting these features onto standard PLCs meant adding external interface boards, signal conditioning modules, and custom firmware patches—adding cost, complexity, and support burden. The client needed a design that could be tailored exactly to each customer’s specification.
Supply Chain and Longevity Concerns
As a systems integrator, the client needed confidence in long-term component availability and design stability. PLC manufacturers discontinue models regularly; customers who deployed systems 10–15 years ago often faced obsolescence challenges when seeking spare controllers or upgrades. Additionally, major PLC vendors undergo periodic acquisitions and consolidations, introducing uncertainty in support and continued availability.
The client wanted to establish direct relationships with their PCB manufacturing partner, ensuring they could maintain and source control boards throughout the product lifecycle—a decade or more—without worrying about vendor discontinuations or price escalations driven by consolidation.
Compliance and Certification Requirements
The client’s customers operated in regulated environments. Many deployments required CE compliance, ATEX certification (for potentially explosive atmospheres in oil and gas facilities), and adherence to IEC 61508 functional safety standards. Integrating ATEX-certified PLCs into larger control systems introduced certification complexity; often, the entire integrated system required re-certification.
Custom PCBs designed and manufactured with full documentation, traceability, and compliance planning from inception, streamlined certification workflows. The client recognized that building safety and compliance into the PCB design phase—rather than retrofitting compliance into a PLC-based system—would benefit their customers significantly.
Our Solution
Comprehensive Needs Assessment and Design Strategy
We initiated the engagement with a detailed consultative phase, working with the client’s engineering team to understand five specific customer use cases spanning different industries and operational requirements. Rather than designing a single universal controller, we identified common design patterns and created a scalable, modular PCB architecture that could accommodate 80% of customer requirements while remaining customizable for the remaining 20%.
Key design decisions included:
Processor and Memory Architecture: We specified a high-performance microcontroller (ARM-based Cortex-M7 processor running at 216 MHz) with 512 KB of embedded flash and 192 KB of SRAM. This provided significantly more processing headroom than typical PLC CPUs while consuming less power, eliminating the need for active cooling in most deployments.
Optimized I/O Subsystem: Rather than generic I/O modules, we designed dedicated circuits for:
- Digital Input Modules: 32 channels of optically isolated 24VDC inputs with 2500V isolation, 7mA nominal current draw, and high-speed pulse capture capability (up to 100 kHz)
- Digital Output Modules: 16 channels of solid-state relay outputs rated for 2A continuous switching, with integrated inductive load protection via freewheeling diodes
- Analog Input: Four 16-bit differential ADC channels with 4–20mA current loop support, thermocouple cold-junction compensation, and 0.1% accuracy across the full industrial temperature range (-40°C to +85°C)
Power Distribution Network: The PCB incorporated a robust power distribution design with:
- Multiple isolated power domains for signal conditioning, processor, and output stages
- Bulk capacitance strategically placed to minimize voltage ripple (<50mV) under transient load conditions
- Thermal vias and copper pours are engineered to dissipate power without requiring external heatsinks or forced-air cooling
Thermal Management: We performed finite-element thermal analysis early in the design cycle, identifying high-power components (voltage regulators and switching outputs) and implementing a copper-weighted PCB stack-up with four inner power and ground planes. This configuration reduced maximum component junction temperature by 18°C compared to a standard two-layer design, extending component lifespan and eliminating thermal stress concerns in industrial enclosures.
Signal Integrity and EMI Control: Industrial environments generate significant electromagnetic interference (EMI) from motor drives, switching power supplies, and high-current welding equipment. We implemented:
- Controlled impedance traces for high-speed digital signals (~50 ohm nominal)
- Segmented ground planes to isolate analog, digital, and power return paths
- Ferrite filters on all external I/O connectors
- Multi-layer shielding on the processor interface bus
Certification-Ready Design: Every design decision was documented according to IEC 61508 design assurance guidelines. We created comprehensive schematic documentation, board layout design records, and thermal/electrical performance reports suitable for submission to ATEX notified bodies. This “design for compliance” approach reduced future certification timelines from 6–8 months to 3–4 months.
Manufacturing Process and Quality Assurance
Given the mission-critical nature of factory automation controllers, we implemented an enhanced manufacturing protocol:
First Article Inspection (FAI): The initial pilot production run (500 units) underwent 100% functional testing, electrical characterization, and visual inspection per IPC-A-600 Class II standards. We captured detailed photographic documentation and electrical test data for every unit, providing the client and their customers with traceability records.
Design for Manufacturability (DFM) Optimization: During design finalization, we conducted a comprehensive DFM review, identifying potential manufacturing challenges:
- Fine-pitch component placement (0402 and 0603 SMD packages) was restricted to areas with adequate via clearance
- Via-in-pad design was employed for high-pin-count connector pads, ensuring reliable solder connections
- Component placement was optimized to minimize solder paste bridging and reduce hand-rework rates
- Panelization was designed to support high-speed automated routing and testing
Solder Reflow Process Control: We implemented statistical process control (SPC) on all reflow ovens, capturing temperature profiles for each batch. Peak solder temperature was maintained at 245–260°C with a dwell time of 10–30 seconds, minimizing thermal stress on components and solder joints.
Functional Test Coverage: Every assembled PCB underwent automated electrical testing covering:
- Power supply voltage regulation and current limits
- All digital I/O channels (high/low output verification, input pulse response)
- Analog input accuracy across the full measurement range
- Communication interface integrity (RS-485, CAN bus)
- Processor boot and flash memory integrity verification
Pass/fail rates consistently exceeded 99.2%, with detected failures typically attributable to solder bridging or component defects—issues caught before shipment.
Volume Production and Cost Achievement
The design achieved the client’s primary cost target: €65–€78 per unit in volume production (10,000+ annual quantity), representing an 82–86% cost reduction compared to standard PLC configurations. This dramatic savings resulted from:
- Elimination of unnecessary subsystems: The custom design included only the required I/O and processing capability, avoiding the cost of unused PLC features
- Optimized component selection: We selected high-volume industrial components with strong supply chain support and competitive pricing
- Simplified assembly: The design reduced hand-soldering operations and complex assembly fixtures
- Streamlined testing: Dedicated test firmware tailored to the design’s specific capabilities reduced test time from 12 minutes per unit (typical for PLC testing) to 4 minutes
Scalability Across Customer Use Cases: The modular PCB design accommodated three distinct configuration variants:
- Standard Configuration: 32 digital inputs, 16 digital outputs, 4 analog inputs (baseline customer profile)
- Extended I/O Configuration: Added 16 additional digital outputs for applications requiring a higher relay count
- High-Speed Configuration: Enhanced processor firmware and signal conditioning for real-time measurement applications
By maintaining a common PCB platform with firmware-driven configuration, the client achieved manufacturing economies while retaining customization flexibility.
Results
Quantified Business Impact
Market Adoption: Within 18 months of product launch, three of the client’s largest customers migrated their production systems to the new custom controller design. Initial adoption was cautious—requiring pilot deployments and side-by-side operational validation—but successful performance and reliability convinced the broader customer base. By month 24, the custom controller represented 65% of the client’s controller sales volume.
Customer Profitability Improvement: The client’s end-customers realized substantial benefits:
- A food processing equipment manufacturer reduced their per-unit controller cost from €420 to €73, enabling them to lower end-product pricing by €200–€250 per unit and win three major contracts it previously lost on cost grounds
- An automotive supplier integrated the controller into their assembly line conveyor system, achieving 99.8% uptime (versus 96.5% with their previous PLC setup) due to the design’s superior EMI immunity
- A pharmaceutical equipment OEM eliminated its custom interface board ($45 per unit) by integrating the required signal conditioning directly into the custom controller PCB
Revenue Growth: The cost advantage enabled the client to pursue market segments previously considered uneconomical. Small and mid-sized equipment manufacturers—previously priced out by high PLC costs—became addressable customers. The client’s annual recurring revenue from controller-based projects increased from €2.8M to €7.1M over three years.
Operational Efficiency: Standardizing on a single PCB platform dramatically simplified the client’s supply chain, firmware maintenance, and technical support. Their engineering team eliminated 30% of their support ticket volume (complexity related to PLC configuration and multi-module integration). Manufacturing lead times dropped from 6–8 weeks to 3–4 weeks.
Supply Chain Resilience: The client established a partnership with IWDF Solutions for ongoing production and sourcing, creating a stable, traceable supply chain. Unlike traditional PLC vendors, which are subject to market consolidation, the client now controls the technical roadmap and long-term availability. Two component obsolescence events (involving the processor and power management IC) were proactively managed through collaborative design revisions with minimal customer impact.
Technical Performance
Field deployments demonstrated exceptional reliability:
- Mean Time Between Failures (MTBF) exceeded 50,000 operating hours across all customer installations
- Temperature stability: Controllers operated reliably from -25°C to +70°C ambient, exceeding the -40°C to +85°C design specification
- EMI immunity: Controllers deployed alongside high-frequency welding and induction heating equipment exhibited zero unplanned shutdowns attributable to electromagnetic interference
Compliance and Certification Success
The design’s compliance-first approach paid significant dividends:
Full design documentation created during development proved invaluable during customer audits and regulatory inspections
ATEX Group II, Category 3G certification (Zone 2, non-classified areas) was achieved in 3.5 months—significantly faster than typical PLC certification timelines
CE compliance and EMC testing (EN 61000-6-2 industrial immunity, EN 61000-6-4 industrial emissions) were completed in parallel without requiring design revisions
Client Feedback
“We were hesitant at first. But working with you changed our perspective. You really listened to our needs and improved the design in ways we hadn’t considered. The final controller performs better and costs significantly less — our customers noticed the difference. Hope we can plan the next project together.”
—Senior Engineering Manager, European Industrial Automation Company.
