How to Request an Accurate PCB Quotation: Gerber Files, Schematics, and Key Information

Accurate PCB quotation is a critical step in electronic product development. Incomplete or unclear quotation information often leads to inaccurate pricing, unexpected cost increases, or manufacturing delays. This article explains how to prepare and submit Gerber files, schematics, and supporting technical data for PCB quotation, and analyzes how each item affects cost, manufacturability, and lead time.

1. Why PCB Quotation Requires More Than a Gerber File

Many engineers assume that Gerber files alone are sufficient for PCB quotation. In practice, Gerber data only defines board geometry and copper patterns, but does not fully describe:

· Electrical performance requirements

· Material constraints

· Reliability expectations

· Assembly compatibility

A professional quotation requires design intent + manufacturing constraints to be clearly communicated.

2. Core Files Required for PCB Quotation

2.1 Gerber Files (Mandatory)

Gerber files are the foundation of any PCB quotation.

Typical Gerber set includes:

· Copper layers (Top / Bottom / Inner layers)

· Solder mask layers

· Silkscreen layers

· Drill files (Excellon)

· Board outline (Profile)

Key points to check before submission:

· Correct layer naming

· Clear board outline

· No missing drill or mask layers

· Consistent units (mm or inch)

Factories use Gerber files to determine:

· Layer count

· Line width / spacing

· Via types

· Overall board size

2.2 PCB Stack-Up Information

Stack-up information may be included as:

· Stack-up drawing

· Notes in fabrication file

· Separate specification document

Required details:

· Total layer count

· Dielectric thickness

· Copper thickness per layer

· Controlled impedance requirements

Stack-up directly affects:

· Material cost

· Lamination cycles

· Yield and lead time

2.3 PCB Fabrication Notes (Fab Notes)

Fabrication notes clarify requirements not visible in Gerber data.

Common fab notes include:

· Surface finish (ENIG, HASL, OSP, etc.)

· Board thickness

· Finished copper thickness

· Solder mask color

· Silkscreen color

· Impedance tolerance

· Special process requirements

Clear fab notes prevent assumptions by the manufacturer.

3. Role of Schematics in PCB Quotation

3.1 Why Some Factories Ask for Schematics

While schematics are not always mandatory, they help manufacturers:

· Identify high-speed or high-current nets

· Understand functional blocks

· Anticipate impedance or isolation requirements

This is especially important for:

· High-speed digital boards

· Power electronics

· Safety-critical designs

Schematics are usually reviewed under NDA.

4. Information That Strongly Affects PCB Price

4.1 Board Size and Quantity

· Panel utilization depends on board dimensions

· Quantity determines setup amortization

Always specify:

· Prototype quantity

· Mass production quantity (if known)

4.2 Line Width / Spacing and Via Technology

Pricing increases significantly with:

· Very fine line/space

· Microvias, blind/buried vias

· HDI structures

These must be clearly stated or verified by DFM.

4.3 Material Requirements

Material choice affects:

· Raw material cost

· Process complexity

Specify if you need:

· Standard FR-4

· High-Tg material

· High-speed or RF laminate

· Halogen-free material

4.4 Special Reliability Requirements

Examples:

· Automotive grade

· High-temperature operation

· Multiple reflow cycles

· IPC class requirements

These directly impact process controls and testing costs.

5. PCBA Quotation vs PCB Bare Board Quotation

If PCBA is required, additional data must be provided:

· BOM

· Pick-and-place file

· Assembly drawings

· Solder paste stencil requirements

Bare PCB quotation and PCBA quotation should be clearly distinguished.

6. Common Quotation Mistakes

Typical issues include:

· Sending Gerber without fab notes

· Missing impedance requirements

· Undefined surface finish

· Not specifying acceptable tolerances

· Mixing prototype and mass-production expectations

These often result in:

· Re-quotation delays

· Engineering questions

· Hidden cost increases later

7. Recommended PCB Quotation Checklist

Before sending files, confirm:

· ✅ Complete Gerber set

· ✅ Drill and board outline included

· ✅ Stack-up defined

· ✅ Fabrication notes prepared

· ✅ Quantity and delivery time specified

· ✅ Special requirements clearly stated

A clear input leads to faster and more accurate quotations.