PCB Shielding Can Design Guide
Design Rules, Materials, Flatness and Manufacturability
A well-designed PCB shielding can improves EMI/RFI protection, supports reliable SMT assembly and reduces manufacturing risk.
This guide covers structure selection, material, thickness, wall height, openings, tolerances, grounding, flatness and design for manufacturability.
A PCB shielding can is a conductive metal enclosure mounted over sensitive electronic components or RF circuits on a printed circuit board.
It helps reduce electromagnetic interference, control radiated emissions, protect signal integrity and create a stable grounding enclosure around the protected circuit.
PCB Shielding Can Design Objectives
Effective EMI/RFI Shielding
The enclosure should provide continuous grounding and minimize openings that may allow unwanted radiation to pass.
Reliable SMT Assembly
The soldering edge should be flat, stable and compatible with the PCB pad and reflow process.
Manufacturability
The design must be suitable for stamping, bending, deep drawing, trimming and mass production.
Cost Optimization
Material, thickness, tooling complexity and assembly method should match the project volume and performance needs.
Choose the Right Shield Structure
The structure should be selected according to assembly, access, geometry and production volume.
| Structure | Main Advantage | Typical Use |
|---|---|---|
| One-Piece Shield | Simple assembly and lower cost | High-volume products without rework access |
| Two-Piece Frame + Cover | Removable cover for testing and repair | RF tuning, inspection and serviceable products |
| Folded Shield | Flexible geometry and lower forming complexity | Low or medium wall heights and custom openings |
| Deep Drawn Shield | Seamless body and strong rigidity | Higher walls and stronger mechanical protection |
Material Selection
Material must be selected together with thickness, geometry, soldering and environmental requirements.
| Material | Design Characteristics | Typical Application |
|---|---|---|
| Tinplate | Cost-effective, good rigidity and solderability | High-volume consumer and communication products |
| Nickel Silver | Good formability, corrosion resistance and solderability | Precision and high-reliability shields |
| Stainless Steel | High strength but greater springback and weaker solderability | Special mechanical requirements |
| Copper / Brass | High conductivity but higher material cost | Special RF or grounding applications |
Material Thickness
PCB shielding cans are commonly produced from thin sheet metal. The correct thickness depends on shield size, wall height, rigidity and forming method.
- 0.15 mm: Lightweight and space-efficient, but more sensitive to deformation.
- 0.20 mm: A common balance of formability, rigidity and cost.
- 0.25–0.30 mm: Greater rigidity, but higher forming force and material cost.
Using unnecessarily thick material may increase cost without improving EMI performance significantly.
Wall Height Design
The shield must provide sufficient internal clearance above the tallest PCB component while remaining practical to form.
As wall height increases, springback, sidewall distortion and flatness become more difficult to control. Taller shields may require larger corner radii, multiple forming stages or a deep drawn structure.
Avoid specifying more height than the circuit and assembly process actually require.
Corner Radius Design
Corner Radius Design
Corner radii reduce forming stress and help prevent cracking, tearing and excessive springback.
Very small radii increase tooling stress and may damage pre-plated surfaces. Larger radii improve formability but use more PCB space.
The minimum practical radius depends on material, thickness, temper, wall height and whether the part is folded or deep drawn.
Vent Holes and Openings
Openings may be required for airflow, connectors, cables, test points, tuning or visual inspection.
However, large or poorly positioned openings can reduce shielding effectiveness and weaken the structure.
- Keep openings as small as functionally possible.
- Avoid long continuous slots.
- Maintain enough material around corners and forming areas.
- Review the opening size relative to the interference frequency.
Grounding and Soldering Edge Design
Reliable grounding is essential for effective EMI shielding. The shield perimeter should provide consistent contact with PCB ground pads.
- Use continuous or regularly spaced ground pads.
- Keep soldering edges flat and free from unnecessary interruptions.
- Avoid openings directly beside critical grounding areas.
- Coordinate shield design with solder paste and stencil requirements.
Shield Cover and Locking Features
Two-piece shields require controlled engagement between the frame and cover. Retention can be created by tabs, dimples, lances, slots or SMT shield clips.
The locking force should prevent accidental cover removal without making inspection and rework unnecessarily difficult.
Frame-to-cover clearance must account for material thickness, plating, forming variation and repeated removal.
Flatness Requirements
Flatness directly affects solder paste contact, grounding and reflow stability.
- ≤ 0.10 mm: Common for general PCB shielding cans.
- ≤ 0.08 mm: Used for higher-precision projects.
- ≤ 0.05 mm: Requires detailed feasibility review and tighter tooling control.
The achievable flatness depends on shield size, thickness, wall height, material and forming method.
Tolerance Design
Apply tight tolerances only to dimensions that affect function, PCB clearance, fit or soldering.
| Dimension Type | Design Recommendation |
|---|---|
| Critical Height | Specify only the tolerance required for component clearance and assembly. |
| Overall Length and Width | Use practical general tolerances unless PCB clearance is very limited. |
| Frame-to-Cover Fit | Control engagement features and functional gap rather than every dimension. |
| Flatness | Define separately because it directly affects SMT assembly. |
| General Dimensions | Use a recognized standard such as ISO 2768 when appropriate. |
SMT Assembly Design Considerations
PCB Ground Pads
Provide sufficient pad width and continuity around the shield perimeter.
Solder Paste
Control paste volume to avoid incomplete wetting or excessive solder buildup.
Keep-Out Area
Maintain clearance between the shield wall and nearby components.
Reflow Support
Large or irregular shields may require careful board support and profile review.
Design for Manufacturability (DFM)
A DFM review should be completed before prototype or production tooling begins.
- Confirm material and thickness.
- Review wall height and corner radii.
- Check bend spacing and forming access.
- Review openings, slots and narrow sections.
- Confirm flatness and critical tolerances.
- Review frame-and-cover fit.
- Confirm packaging and automated assembly requirements.
Prototype Before Production
Prototype verification helps confirm dimensions, fit, flatness, cover retention and PCB assembly before production tooling is finalized.
Prototype methods may include chemical etching, laser cutting, bending or simple prototype tooling. Production tooling is more suitable after the design is stable and annual demand is confirmed.
Common PCB Shielding Can Design Mistakes
Avoiding these issues can reduce tooling changes and shorten development time.
Wall Height Too High
Unnecessary height increases springback, tooling complexity and flatness risk.
Corner Radius Too Small
Sharp corners increase forming stress and may cause cracking or coating damage.
Openings Too Large
Large windows may reduce shielding performance and weaken the structure.
Material Too Thin
Insufficient rigidity can cause handling and reflow deformation.
Too Many Tight Tolerances
Over-tolerancing increases tooling cost and production risk.
Poor Grounding Layout
Interrupted pads or insufficient soldering area can reduce shield effectiveness.
No Rework Strategy
A one-piece shield may be unsuitable when circuit access is required.
No Prototype Verification
Fit, flatness and assembly problems may only appear after tooling is completed.
PCB Shielding Can Design Checklist
Use this checklist before releasing the design for tooling.
Typical Applications
Telecommunication
RF modules, routers, optical communication and CATV equipment.
Automotive Electronics
Control units, communication modules and sensor electronics.
Medical Devices
Compact electronic modules requiring stable shielding and assembly.
Consumer & Industrial
Wi-Fi, IoT, smart devices, power control and industrial PCB assemblies.
HEXIN Shielding Can Design Support
HEXIN supports custom PCB shielding cans from design review and prototype development through tooling and mass production.
- 2D drawing and 3D file review
- Material and thickness recommendations
- One-piece and two-piece shield structures
- Folded and deep drawn designs
- Prototype and production tooling
- Flatness and dimensional inspection
- Tape-and-reel or tray packaging options
Related PCB Shielding Guides
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Frequently Asked Questions
Common questions about PCB shielding can design and manufacturing.
What material is best for a PCB shielding can?
Tinplate and nickel silver are the most common choices. The best material depends on cost, corrosion resistance, forming and soldering requirements.
How thick should a PCB shielding can be?
A thickness of 0.20 mm is common, while 0.15–0.30 mm may be selected depending on size, rigidity and forming method.
What is the difference between one-piece and two-piece shields?
A one-piece shield is soldered as a complete enclosure, while a two-piece shield uses a soldered frame and removable cover.
How high can a shielding can wall be?
The practical wall height depends on material, thickness, radius and forming process. Taller designs may require deep drawing.
What flatness is normally required?
A common target is ≤ 0.10 mm. Higher-precision projects may require ≤ 0.08 mm or ≤ 0.05 mm.
Can vent holes be added?
Yes, but the size and position should be reviewed to avoid reducing shielding performance or mechanical strength.
Can HEXIN design from a PCB layout?
A PCB layout can support the review, but a dimensioned drawing or 3D file is recommended before tooling.
Should I choose tinplate or nickel silver?
Tinplate is cost-effective, while nickel silver offers good corrosion resistance and stable solderability.
Do I need a prototype?
A prototype is recommended when fit, flatness, component clearance or cover retention must be verified.
Can shielding cans be supplied in tape and reel?
Yes, suitable frames, covers and shield clips can be designed for tape-and-reel packaging.
Need Help Designing a PCB Shielding Can?
Send us your drawing, PCB layout, material preference, quantity and assembly requirements. Our engineering team will review the design and provide practical manufacturing recommendations.