How We Fixed a Gerber Hole Issue for a Smart Sensor Client
100%
Assembly Success Rate
0
Rework Required
Faster Board Fitting
48h
Turnaround on Fix

The Challenge

When one of our U.S.-based smart sensor clients reached out, they had a frustrating problem — one that only became apparent after production had already shipped. Their engineering team was struggling to mount boards during final assembly, and the root cause traced back to the original Gerber files: the through-holes were simply too small.

The undersized holes made it physically difficult to insert and secure components. Technicians were forced to apply excessive force, increasing the risk of board damage, component misalignment, and production delays. What should have been a smooth assembly process had turned into a time-consuming bottleneck — costing real money on the production floor.

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The Problem

Undersized Gerber Holes

Original drill specifications in the Gerber files were too tight, causing component insertion difficulty during U.S. final assembly.

🔵
Our Solution

Optimized Holes + Pin Headers

We enlarged hole diameters to standard tolerances and replaced the connector type with pin headers for reliable, tool-free mating.

BEFORE — UNDERSIZED HOLESCONNECTOR — MISFIT⚠ 0.8mm⚠ 0.8mm⚠ 0.8mmASSEMBLY FAILURE — FORCE REQUIREDREWORK / DELAY / COMPONENT DAMAGE RISKBELI FIXAFTER — PIN HEADERS + ENLARGED HOLESPIN HEADER — PERFECT FIT✓ 1.2mm✓ 1.2mm✓ 1.2mmSMOOTH ASSEMBLY — ZERO REWORKPRODUCTION EFFICIENCY RESTORED ✓

Root Cause Analysis

Upon receiving the client's Gerber files, our engineering team performed a thorough Design for Manufacturability (DFM) review. The issue was clear: the original drill hole diameters had been specified without accounting for the standard insertion tolerances required for the connectors used during assembly in the U.S.

When hole diameters are undersized relative to the component lead diameter — even by fractions of a millimeter — assembly workers face significant resistance during insertion. This not only slows down the production line but also creates the very real risk of PCB pad lifting, lead deformation, or cracked solder joints.

Drill Hole Specification — Before vs After
Original Spec
0.8mm
Drill hole diameter
❌ Insufficient clearance
BELI Fix
Optimized Spec
1.2mm
Enlarged + pin headers
✅ IPC-2221 compliant

Our Engineering Solution

Once the root cause was confirmed, our team acted swiftly. The fix involved two complementary changes to the Gerber files and BOM that, together, completely eliminated the assembly issue.

01

Gerber File DFM Audit

We conducted a full review of the original Gerber files against IPC-2221 standards, identifying all undersized drill holes and flagging additional potential DFM risks for future production runs.

02

Hole Diameter Enlargement

We revised the drill files to increase hole diameters to provide proper annular ring clearance and component lead insertion tolerance, meeting industry-standard assembly requirements without compromising board integrity.

03

Connector Swap: Standard Holes → Pin Headers

We recommended switching from the original connector footprint to a standard pin header configuration. This change improved insertion reliability dramatically, reduced component cost, and made the board much more assembly-friendly for the client's U.S. team.

04

Prototype Verification & Approval

We produced a small prototype batch with the updated files and coordinated with the client for hands-on verification by their assembly team before committing to full production volume.

The Result

The outcome was immediate and measurable. With the revised Gerber files and updated component specification, the client's assembly team in the United States was able to mount the boards smoothly and without any specialized tooling or excess force.

Beyond resolving the immediate issue, our DFM review also surfaced several additional areas for layout improvement, which we documented in a detailed engineering report. The client now submits all new designs through our DFM review process before tape-out — helping them catch issues upstream, before they become production-floor problems.

"

"We had been struggling with this for weeks. Beli identified the issue within hours of receiving our files, and within 48 hours we had a revised set ready to produce. The assembly team in the U.S. couldn't believe how smooth it went after the fix."

Engineering Lead, Smart Sensor Manufacturer, United States

Key Takeaways

This case is a great example of why DFM (Design for Manufacturability) review is a critical part of any PCB production workflow — especially when designs cross borders and are assembled in different facilities with different tooling setups.

A few millimeters in your Gerber file can translate to hours of production delays and thousands of dollars in rework costs downstream. At BELI Technologies, we don't just manufacture boards — we act as an extension of our clients' engineering teams, proactively identifying and solving issues before they ship.

Case Details
  • Industry: Smart Sensor / IoT
  • Client Region: United States
  • Issue: Undersized Gerber drill holes
  • Fix: Hole resize + pin header swap
  • Turnaround: 48 hours
Key Outcomes
  • 100% assembly success rate post-fix
  • Eliminated forced insertion risk
  • No PCB damage or pad lifting
  • Reduced per-board assembly time
  • Ongoing DFM partnership established
DFM Review Gerber Optimization PCBA IPC-2221 Smart Sensors BOM Optimization
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