Skip to content

PV Materials Lab

Main Navigation Basics Materials Design Process Reliability & Failures Standards Frontiers Insights Series

English

English

Appearance

Sidebar Navigation

Basics

History of PV

How PV Works

Solar Cell Basics

PV Module Basics

Glossary

Materials

Solar Cells

PERC

TOPCon

HJT

BC

After 28.29%: How Much Room Is Left in the BC Cell Efficiency Race?

Perovskite & Tandem

PV Glass

Encapsulant Films

"China-Made Pellets" for POE Encapsulants: After Going from Zero to One, How Far Has Localisation Come?

Backsheets

Ribbons

Copper-Clad Aluminum (CCA) Ribbon: The Cost Is Tempting, So Why Are Leading PV Makers Still Holding Back?

The Workhorse Alloy of Low-Temperature Ribbon: Sn32Pb42Bi26 in PV Ribbon Today and Tomorrow

Copper Tops 110,000 CNY/t: How Far Is Copper-Clad Aluminium Ribbon from Mass Production?

Soldering Flux

Frames

What a PV Module Frame Actually Does: The Module's Skeleton

Frame Materials: Why 6063 Aluminum Alloy?

Steel Module Frames: How Far Has Mass Production Got?

Silicones

Junction Boxes

What a Junction Box Does: Functions and Roles

Bypass Diodes

Connectors

How a Small MC4 Connector Has Stayed on Top in PV for Twenty Years

MC4 vs. MC4-Evo 2: What Is Actually Different?

Other Materials

Swapping Glass for a Film: How ETFE Makes PV Modules Flexible

Design

Layout & Circuit Design

Structure & Mechanical Load

Bifacial & Glass-Glass

BOM & Cost Reduction

Process

Stringing

Layup

Lamination

Framing & J-Box Mounting

EL & IV Testing

Reliability & Failures

Overview

55 PV Plants Surveyed: Is One in Five Modules Cracked? How to Read the Numbers

MQT 01 Visual Inspection

MQT 02 Maximum Power Determination

MQT 03 Insulation Test

MQT 04 Temperature Coefficients

MQT 06 Performance at STC

MQT 07 Performance at Low Irradiance

MQT 08 Outdoor Exposure

MQT 09 Hot-Spot Endurance

The Hot-Spot Effect in PV Modules, Step by Step: How a Shaded Cell Gets Driven Down to −16.8 V

MQT 10 UV Preconditioning

MQT 11 Thermal Cycling (TC)

The TC200 Thermal Cycling Test for PV Modules: Test Conditions, Failure Signatures and Failure Mechanisms

MQT 12 Humidity Freeze (HF)

MQT 13 Damp Heat (DH)

DH1000 Damp Heat Testing of PV Modules: Test Conditions, Failure Signatures and Failure Mechanisms (TOPCon as an Example)

MQT 14 Robustness of Terminations

MQT 15 Wet Leakage Current

MQT 16 Static Mechanical Load

MQT 17 Hail Test

MQT 18 Bypass Diode Testing

MQT 18.1 Bypass Diode Thermal Test (Junction Temperature)

MQT 18.2 Bypass Diode Functionality Test

MQT 19 Stabilization

MQT 20 Cyclic (Dynamic) Mechanical Load

MQT 21 Potential-Induced Degradation (PID)

PV PID Series #1: High Voltage Difference, the Entry Ticket to PID

PV PID Series #2: PID-s, PID-p and PID-c, the Root Causes of Three Kinds of PID

PV PID Series #3: Temperature, Humidity, Glass and Encapsulant, the Other Half of What Decides PID

PV PID Series #4: How Is PID Tested, and How Should You Read a Test Report?

PV PID Series #5 (Finale): Suspected PID in a Plant - How to Investigate, Recover and Prevent It

MQT 22 Bending Test

Tests from Other Standards

Thermal Runaway (IEC 62979)

LID

LeTID

UVID

Microcracks

Snail Trails

Backsheet Cracking & Yellowing

Junction Box Failures

Delamination

Standards

Standards Basics

What Every PV Professional Should Know: How Do IEC 61215 and IEC 61730 Differ?

IEC 61215

IEC 61730

IEC TS 62915

Changed a Material: Does the Certificate Still Count? A Guide to the IEC TS 62915 Retesting Specification

Certification in Practice

Frontiers

AI for PV

AI Is Here: Will PV Technical Jobs Be Replaced?

Space PV

Nearly CNY 100 Million on "Roll-Up Solar Wings": Space PV Through the Eyes of a PV Engineer

Perovskite & Tandem

The New York Times Says Tandem Cells Could Help the US Catch China in Solar. We Doubt It

Zero-Busbar (0BB)

Shingled Modules

Lightweight & Flexible PV

BIPV

Vehicle-Integrated PV

Insights

Weekly Reports

Monthly Reports

News & Views

Stop Calling Appliance Makers "Outsiders" in Solar

Musk Raises 200 GW Again with Jensen Huang: How Long Will This Solar Story Run?

Offshore PV Corrosion Protection Gets an Industry Standard: The Text Isn't Out Yet, but Your BOM Should Be Ready

Perovskite Modules Head to Orbit Again: What's Different About GCL Optoelectronics' In-Orbit Test?

Payrolls Up Just 29,000, Rate-Hike Bets Cool: Can PV Breathe Easier?

Will China's PV Market Improve by Year-End? Our View: The Fall Has Stopped, but Recovery Is Still Far Off

First Price Rise in October: Three Module Makers Raise Prices — Is the Slide Over?

Buyer's View

Price Trends

Series

PID Series

Junction Box Series

Ribbon Series

Flux Series

Encapsulant Series

PV Glass Series

Frame Series

On this page

Home / Reliability & Failures

Snail Trails

Level: IntermediatePlanned

Formation mechanism and prevention of snail trails

Coming soon

Articles for this section are being prepared. Check back soon.

Pager

Previous pageMicrocracks

Next pageBacksheet Cracking & Yellowing

PV Materials Lab · A team with 10+ years in PV module R&D and engineering · About us

© 2026 PV Materials Lab