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PCB layout & design

FAQ About PCB Layout

At WELLER, we combine technical excellence with environmental responsibility in every printed circuit board design. Below you'll find answers to the most frequently asked questions about our sustainable PCB layout practices.

PCB layout design is the process of arranging electronic components and routing electrical connections on a printed circuit board (PCB). It ensures proper functionality, signal integrity, and manufacturability of the board. Key steps include schematic capture, component placement, trace routing, and design rule checks (DRC).

To provide a comprehensive PCB layout analysis and quotation, please submit these essential files:

1. Schematic Design Files
  • Primary format: DSN (OrCAD)
  • Supplemental: PDF schematic for quick reference

2. Mechanical Drawings
  • Preferred format: DXF CAD files (For enclosure integration & board shape verification)

3. Complete BOM (Bill of Materials)
  • Must include: Component packages, values, manufacturers, and MPNs (Critical for footprint validation and sourcing)

4. Component Datasheets
  • Required for: All active/passive components (Ensures electrical compliance and placement rules)

5. Special Design Requirements Specify: PCB stackup, impedance controls, material specs, or DFM constraints

We use three mainstream PCB design software: Altium Designer, Cadence Allegro & KiCad.

The best PCB design software depends on your project needs:

  • Cadence Allegro: Ideal for high-speed PCB design and complex multilayer boards.
  • Altium Designer: Perfect for industrial PCB layouts with balanced features.
  • KiCad: A free, open-source tool for hobbyists and simple electronics.

To ensure signal integrity in PCB design:

  • Use proper grounding techniques (e.g., ground planes).
  • Minimize trace lengths for high-speed signals.
  • Avoid sharp angles in traces (use 45° or curved routing).
  • Apply controlled impedance routing for RF/microwave designs.
  • Insufficient clearance: Violating design rule checks (DRC) can cause short circuits.
  • Poor component placement: Leads to inefficient routing and noise issues.
  • Ignoring thermal management: Overheating due to inadequate copper pours or vias.
  • Not considering manufacturability (DFM): Always follow PCB fabrication guidelines.

A well-designed PCB layout reduces electromagnetic interference (EMI) by:

  • Separating high-speed and analog signals.
  • Using shielded traces and proper grounding.
  • Avoiding loops in return paths.
  • Following EMC compliance standards (e.g., FCC, CE).

The final PCB layout package files that Weller will provide:

 

_asm file: This is for mechanical file for assembly reference.

 

_cam file: This PCB Gerber file for PCB fabrication reference.

 

_dxf file: This is Structure drawing,for mechanical reference.

 

_pcb file: This is final PCB file generated from Cadence Allegro, for the usage of modification of the PCB diagram or the debugging of circuit diagram.

 

_smd file: This is the paste file for PCB assembly house usage.

 

.PCBDOC file: This is the altium design software file only for PCB designer reference.