PCB Design for Manufacturability Guidelines

Designing for manufacturability early in the PCB development process can help reduce cost, improve yield and prevent unnecessary engineering changes later. Westak works with customers to evaluate materials, stackups, copper weights, trace and space, drilling, via structures, controlled impedance and other fabrication requirements before production.

The guidelines below highlight common PCB design considerations. Actual capability may vary based on layer count, material, copper weight, board thickness and technology requirements, so we encourage early engineering review for advanced designs.

Materials & Construction

Material selection can affect electrical performance, thermal reliability, lead time and cost. Whenever possible, specify required performance characteristics rather than limiting the design to a specific laminate manufacturer or product.

Considerations may include:

FR-4 and high performance laminates
Low-loss/High-speed materials
Polyimide or specialty materials
Copper foil requirements
Core vs. foil construction
Material availability considerations

Westak can review material requirements and recommend manufacturable alternatives when appropriate.
Learn more: Material Options Available

Copper Weight, Trace & Space

Trace and space capability is closely related to copper thickness.
As copper weight increases, additional spacing is generally required to maintain etch control and manufacturability. Designs using heavier copper should be reviewed carefully before layout is finalized.
Important considerations include:

Finished copper weight
Minimum trace width
Minimum spacing
Copper distribution
Annular ring requirements
Copper-to-board-edge clearance

For designs requiring fine lines, heavy copper, or unusual copper combinations, contact Westak engineering for review.

Mechanical Drilling & Aspect Ratio

Drill size, finished hole size, board thickness and plating requirements all affect manufacturability.
Smaller holes in thicker boards can create high aspect ratios that may require design changes or special processing.
Consider:

Mechanical drill size
Finished hole diameter
Plated versus non-plated holes
Hole tolerance
Annular ring
Board thickness
Aspect ratio
Press-fit hole requirements
Slot dimensions and tolerances

For unusually thick boards or small finished holes, we recommend an engineering review before releasing the design.

Blind/Buried Vias and Microvias

Blind vias, buried vias and laser-drilled microvias can significantly affect stackup construction, lamination cycles and cost.
Design considerations may include:

Blind vias
Buried vias
Laser-drilled microvias
Sequential lamination
Stacked or staggered microvias
Via-in-pad
Capture pad size
Dielectric thickness
Aspect ratio

HDI designs should be reviewed early so the via structure and stackup can be optimized before layout is finalized.

Via Fill Options

Via fill requirements should be identified clearly on the fabrication drawing.
Available processes may include:

Non-conductive via fill
Conductive via fill
Copper-filled microvias
Via-in-pad plated over (VIPPO)

The appropriate fill method depends on assembly, thermal, electrical, and reliability requirements.

Controlled Impedance

Controlled impedance designs should clearly identify the target impedance, tolerance, applicable layer, trace geometry, and reference plane.
Westak can assist with impedance modeling and stackup development during the design stage.
For controlled impedance designs, provide:

Target impedance
Impedance tolerance
Single-ended or differential requirement
Applicable layer
Trace width
Differential spacing, if applicable
Reference plane
Copper weight
Finished board thickness
Material requirements
Coupon requirements, if applicable

Final trace width and dielectric thickness may be adjusted during engineering review to achieve the required impedance while maintaining manufacturability.
For additional guidance, review our PCB Stackup & Controlled Impedance Considerations

PCB Surface Finish Options

Surface finish selection should be based on assembly method, shelf life, wire bonding, contact requirements and end-use environment.

Common finishes:

ENIG (Electroless Nickel Immersion Gold)
Immersion Silver
HASL
Lead-Free HASL
OSP (Organic Solderability Preservation)

Additional finishes:

ENEPIG (Electroless Nickel, Electroless Palladium, Immersion Gold)
EPIG (Electroless Palladium, Immersion Gold)
EPAG
Electrolytic Hard Gold Body
Electrolytic Nickel Body
Soft Bondable Electrolytic Gold
Selective Finishes

Availability may vary by facility and design requirements. Contact Westak for review of finish requirements.

Standard Manufacturing Panel Sizes

Westak utilizes multiple manufacturing panel sizes depending on board dimensions, material and production requirements.
Common panel sizes include:
12"x18", 18"x24", 21"x24"

Final panel utilization is determined during CAM tooling. Designers generally do not need to design to a specific fabrication panel unless there is a customer or assembly-driven array requirement.

Before Releasing Your Design

Before finalizing your PCB design, confirm that the following requirements have been defined where applicable:

Material or performance requirements
Finished board thickness
Copper weights
Minimum trace and space
Finished hole sizes and tolerances
Blind/buried via structure
Via fill requirements
Controlled impedance targets
Surface finish
Solder mask requirements
Board outline and tolerances
Fabrication drawing notes
IPC-D-356A netlist

Providing complete and clearly defined fabrication requirements helps reduce engineering questions and delays during quoting, CAM tooling, and production.
For additional guidance, review our PCB Tooling Package Requirements

PCB Design for Manufacturability Lunch & Learn

Westak offers customized Design for Manufacturability presentations for engineering and PCB design teams.
Sessions can cover general PCB manufacturing best practices or focus on specific topics such as:

Stackup development
Controlled impedance
HDI and microvias
Materials
Mechanical drilling
Via structures
Surface finishes
Fabrication data preparation
Common PCB cost drivers

Presentations can be tailored to your team’s technology and design requirements.
Contact Westak to schedule an on-site or virtual DFM session.

Have a Design You'd Like Us to Review?

Westak’s engineering team can review your proposed PCB construction before release to help identify manufacturability concerns, cost drivers, material issues, and potential fabrication challenges early in the design process.
Send us your preliminary stackup, fabrication drawing, or design requirements and we’ll help evaluate the best manufacturing approach for your application.

PCB Design Guidelines