Extruded Aluminum Electronics Enclosure for High Volume Production

KEA TECHNOLOIGES INC.

(LITTLETON, MA)

Project Summary:

Designed a high-volume aluminum enclosure to house and protect an electronic circuit board operating in a constrained, harsh environment. I was the sole mechanical designer responsible for enclosure design from concept through pre-production, including thermal management, environmental sealing, EMI shielding, manufacturability, and supplier collaboration.

The design was developed for scalable production while meeting performance, cost, and reliability requirements. Validation activities included structured design risk analysis, experimental testing, and compliance verification.

Note: Due to confidentiality restrictions, detailed CAD models and prototype images are not shown on this site. Additional design visuals and documentation are available for interview review.

Start Up-Shut Down System: About

OBJECTIVE & REQUIREMENTS

The enclosure was required to meet the following objectives:

Dissipate heat from a high-power electronic component through direct thermal coupling to the enclosure
Meet IP54 ingress protection requirements
Provide EMI shielding via a continuous conductive enclosure
Withstand vibration and temperature extremes
Achieve design-to-cost targets suitable for high-volume production
Be designed for ease of assembly, minimizing part count and assembly time
Conform to strict size and packaging constraints
Include integrated mounting features for secure installation

CONSTRAINTS & DESIGN CONSIDERATIONS

The design was developed under several practical constraints that influenced material selection, geometry, and manufacturing approach:

Limited internal volume and fixed connector locations
Concentrated thermal load at the PCB CPU
Sensitivity of sealing performance to gasket compression and fastener preload
Risk of enclosure deformation under assembly torque
Manufacturing variability across extrusion, machining, and gasket processes
Need for repeatable, robust assembly in a production environment

These considerations informed early design decisions, risk analysis activities, and validation planning.

CONCEPT & DESIGN APPROACH

The enclosure design approach was developed to balance thermal performance, environmental protection, manufacturability, and cost for high-volume production.

Several enclosure concepts and materials were evaluated before selecting 6063 aluminum due to its favorable thermal conductivity, corrosion resistance, and suitability for extrusion-based manufacturing. An extrusion-based approach was chosen to minimize per-unit cost while maintaining dimensional consistency at scale.

The final enclosure design consists of:

Extruded aluminum top and bottom sections forming the primary structural and thermal body
Machined front and back plates to accommodate connector interfaces and sealing feature

This configuration provided flexibility for interface features while keeping tooling and production costs low.

The enclosure incorporates an integrated heat sink, using direct thermal coupling between the circuit board’s CPU and the aluminum housing through a high-conductivity thermal interface material. External cooling fins were included in the extrusion profile to increase surface area and improve passive heat dissipation.

Environmental sealing was achieved using a closed-cell nylon/EPDM foam gasket located between the extruded housing and the front and back plates. The gasket geometry and compression were designed to meet IP54 ingress protectionrequirements while accommodating manufacturing tolerances. A die-cut gasket was selected to balance sealing performance, cost, and scalability for high-volume production.

A structured design risk analysis (DFMEA) was conducted to identify potential failure modes related to sealing, thermal performance, fastening, and assembly. High-risk items were addressed through design changes, material selection, and tolerance adjustments prior to prototype release.

Internal features were designed to support assembly and long-term reliability, including:

Integrated mounting rails for secure PCB installation
Continuous conductive paths to support EMI shielding
Geometry optimized for extrusion, including consistent wall thicknesses and manufacturable profiles

All components were fully modeled and released using Onshape, with design iterations informed by supplier feedback, prototype testing, and manufacturing constraints.

ENGINEERING ANALYSIS, DOE & DESIGN VALIDATION

Engineering analysis and validation activities were performed to support design decisions and close risks identified during the design risk analysis (DFMEA) prior to release.

Thermal validation included evaluation of multiple thermal interface materials with varying conductivities to ensure sufficient heat transfer from the PCB to the enclosure under worst-case operating conditions. The final material was selected based on measured performance margin and supplier qualification.

Tolerance stack-up analyses were conducted on enclosure components, gasket interfaces, and connector cutouts to ensure proper fit, sealing compression, and repeatable assembly. Fastener torque calculations were completed to establish initial clamping force targets for enclosure assembly and internal PCB mounting.

During early prototype testing, bowing of the front and back plates under fastener preload and insufficient gasket compression were identified as potential risks to sealing performance. To address this, a design of experiments (DOE) was conducted to quantify the relationship between gasket material, compression behavior, applied torque, and enclosure deformation.

Three gasket materials were evaluated:

Silicone sheet
Neoprene sheet
Neoprene/EPDM foam sheet

Six control measurement points were defined on the front and back plates. Each gasket material was tested across incremental torque levels, and compression was measured at each location using pin gauges to quantify local compression and plate bowing behavior.

DOE results were used to identify the gasket material and torque specification that achieved sufficient compression to meet sealing requirements while minimizing enclosure deformation. Based on this data, the neoprene/EPDM foam gasket and a revised fastener torque specification were selected to balance sealing performance, structural stability, and assembly robustness.

EMI performance was also validated through testing, confirming that the conductive enclosure design provided effective electromagnetic shielding and met required EMI compliance criteria.

MANUFACTURING, PROTOTYPING & ITERATION

The enclosure was developed using a production-focused approach, progressing through multiple prototype stages to validate design intent, manufacturability, and performance.

Initial prototypes were produced using 3D printing to evaluate overall form, fit, and internal packaging. This was followed by CNC-machined aluminum prototypes used for functional testing, including thermal, vibration, temperature, drop, and sealing performance.

Design refinements to gasket material selection, fastener torque specification, and enclosure interface geometry were implemented based on DOE results. Additional updates were made to improve assembly robustness, reduce component cost, and increase sealing reliability.

Following these updates, a pilot build of 10 units was produced using CNC-machined components and laser-cut gaskets to support compliance and validation testing, all of which were successfully passed.

The design is currently transitioning to production using aluminum extrusion for the enclosure body and die-cut gaskets, supporting scalable, high-volume manufacturing.

RESULTS, PRODUCTION STATUS & SKILLS

Results & Production Status:

Achieved IP54 ingress protection
Met thermal performance requirements with margin
Resolved enclosure deformation and sealing risks through data-driven validation
Successfully passed compliance and validation testing
Design approved for transition to high-volume production
Planned production run of 1,000 units, with manufacturing ramp scheduled for 2026
Successfully passed EMI testing, confirming effective electromagnetic shielding

Skills Demonstrated:

Mechanical enclosure design
Thermal management and heat dissipation
Environmental sealing and gasket design
Design of Experiments (DOE)
Design risk analysis (DFMEA)
Tolerance analysis and fastener preload design
DFM/DFA for scalable manufacturing
Supplier collaboration and cost optimization
CAD: Onshape
Prototyping, testing, and iterative design