Boosting PCB Impact Resistance from Design to Production

Ever dropped your phone, only to find the screen intact—but the device won’t turn on? Or experienced equipment failures after minor bumps during transport? Often, the root cause lies in poor impact resistance of the pcb prototype inside.

A PCB’s structural integrity is critical to the lifespan of electronic products. Mechanical shock doesn’t just jar components—it can cause microfractures in the substrate, delamination between layers, and even torn solder joints or dislodged connectors. Here's how to strengthen your design from the ground up.

Understand How Shock Affects PCBs

When a device experiences impact, the force ripples through the PCB. On a microscopic level, base materials can crack, copper layers may loosen, and interlayer adhesion might fail. Heavier components like capacitors and connectors can tear free, leaving solder joints broken. In extreme cases, the board may warp visibly, bending like a banana.

Structural Design Choices That Matter

1. Board Thickness and Size

Don’t chase ultra-thin boards blindly. A standard 1.6mm board may suffice for consumer electronics, but industrial and automotive environments demand thicker substrates—2.0mm or more—to reduce flexing and improve shock absorption by over 40%.

Large PCBs also suffer under impact. Splitting large boards into smaller modules connected via connectors improves reliability. For instance, a drone’s control board split into a core module and expansion unit saw a 30% improvement in shock survival rates.

2. Material Selection

Enhanced FR-4 laminates offer roughly 30% better impact resistance than standard FR-4 by optimizing resin composition. In aerospace or military applications, polyimide (PI) substrates outperform due to their spring-like toughness.

Copper foil type also plays a role. Rolled annealed copper withstands mechanical stress better than electro-deposited copper. Using thicker copper—up to 70μm—adds mechanical strength, effectively forming an internal armor.

Strategic Component Placement

Heavier parts should be centrally located. Batteries and power drivers placed in the center minimize torque during shock events. A car GPS board that moved a 20g IC from the corner to the center cut its failure rate by 60%.

Tall parts like connectors should be reinforced. Adding side brackets reduces wobble and potential damage—one industrial sensor reduced connector sway from 3mm to under 1mm using this method.

Solder Joint Durability: Invisible but Critical

Solder joints are the “seatbelts” of surface-mounted devices. Extending pad length by even 0.3mm on an 0805 resistor increases shear resistance by 20%. For through-hole parts, adding extra solder at the pin base creates a fillet that absorbs stress.

Components like BGAs or CSPs benefit greatly from underfill. This epoxy fills gaps beneath the chip, dramatically improving survival during drop testing. Smartphone CPUs almost always use this technique to withstand daily wear and tear.

Manufacturing Tactics to Boost Strength

1. Lamination Process

Multi-layer boards are prone to interlayer delamination. To counter this, use surface roughening before lamination and apply consistent heat (170–180°C) and pressure (20–30?kg/cm2) for up to 90 minutes. Cutting this step short—even by 10 minutes—can lead to costly batch failures in impact tests.

2. Drilling & Plating

Drill burrs create weak points. When working with PI substrates, increase spindle speed and follow up with chemical deburring. Wall plating should be no less than 25μm thick; consider heavy copper plating for added mechanical support.

Post-plating thermal cycling tests can reveal latent issues in hole integrity, helping prevent crack propagation later on.

3. Surface Finish

Between HASL and ENIG, the latter is better suited for impact resistance. ENIG’s solder joints are more ductile and less likely to crack. A smart wearable device switched to ENIG and improved its drop-test solder joint survival rate from 70% to 95%.

Testing and Verification

Follow the IEC 60068-2-27 standard to simulate real-world drops. Consumer electronics typically undergo 1000G impact over 1ms, while automotive PCBs must survive up to 3000G.

Verification involves more than visual checks. Use multimeters to test continuity, microscopes for solder joint inspection, and even X-ray for internal voids. One automotive board appeared intact but failed due to hidden copper trace fractures—missed only because internal defects were overlooked.

Using Tools to Finalize Impact-Ready Designs

Before production, reviewing Gerber files in a pcb file viewer helps validate copper layers, hole alignment, and silk screen accuracy. At PCBGOGO, we encourage every designer to check manufacturability through these tools. Our team helps ensure your pcb prototype not only performs electrically but also survives the roughest handling.

Conclusion

Impact resistance isn’t an afterthought—it must be baked into PCB design and production. From choosing thicker substrates and rolled copper to reinforcing solder joints and optimizing lamination processes, every detail matters. Building robust PCBs ensures products survive real-world abuse, delivering lasting performance in demanding environments.