2026-04-07
Why Hi-Pot Testing is Non-Negotiable for High-Reliability PCBA
1. What is Hi-Pot Testing?
It is a mandatory safety test (UL, IEC, GB) that applies high voltage to a device's insulation to ensure it won't shock the user.
The Goal:Detect insulation breakdowns, material defects, or manufacturing flaws before they reach the field.
2. Core Technical Standards
| Feature | Standard Requirement | Medical Grade (ISO 13485) |
| AC Test | 1.5kV – 4.0kV (60s) | Enhanced Insulation Specs |
| DC Test | 2.1kVdc – 5.6kVdc | Ultra-low Leakage |
| Leakage Limit | 5mA – 10mA | < 0.5mA |
3. Hi-Pot vs. Insulation Resistance (IR)
IR Test: Low voltage (500Vdc). Measures quality ($>100\text{M}\Omega$). Non-destructive.
Hi-Pot Test: High voltage. Stress-tests strength. Determines if breakdown occurs.
Sequence: We always perform IR first, followed by Hi-Pot.
4. Design for Compliance: KLS Engineering Insights
To pass Hi-Pot consistently, your PCB Layout must consider:
- Creepage & Clearance: Strict adherence to safety distances.
- Isolation Slots: Physical milling on the PCB to stop high-voltage tracking.
- Rounded Pads: Avoiding sharp corners to prevent corona discharge and arcing.
- Cleanliness: Ionic contamination control is vital for high-voltage stability.
5. Why Test Bare Boards?
While standard for finished goods, KLS offers Hi-Pot testing on bare PCBs for:
- Detecting Layer Defects: Finding resin voids or delamination in multi-layer boards.
- Via Quality: Checking for cracks or plating holes in blind/buried vias.
- High-Voltage Resilience: Essential for Medical, Power Electronics, and Specialized Power Supplies.
