Can your PCB tape survive extreme heat?
In electronics manufacturing, especially PCB assembly, heat resistance is not just a nice-to-have — it’s a must. Overheating can cause adhesive breakdown, poor insulation, and even equipment failure. That’s why choosing the right tape matters.
Today, we’re comparing 3M 851 tape with conventional PCB tapes to see which performs better when the heat is on. We’ll look at strengths, weaknesses, and ideal applications so you can choose the right fit for your project.
Why High-Heat Performance Matters in PCB Applications
During soldering, reflow, or wave processes, temperatures can exceed 200°C. The wrong tape may shrink, lose adhesion, or leave behind residue that affects circuit performance.
Both 3M 851 and traditional PCB tapes are designed for electronics use, but their materials and performance differ. In this blog, we’ll compare them factor-by-factor to help you make an informed decision.
3M 851 Tape Overview
3M 851 tape is a polyester-based tape designed for electrical insulation and high-temperature masking.
- Withstands continuous temperatures up to around 130°C (and higher for short bursts).
- Features a strong silicone adhesive for clean removal.
- Excellent for coil wrapping, splicing, and high-heat masking during PCB soldering.
Common uses:
- Masking during wave soldering
- Insulation for transformers and coils
- Holding components in place during assembly
Conventional PCB Tapes Overview
Conventional PCB tapes include polyimide (Kapton), polyester, and glass cloth tapes.
- Polyimide tapes often resist up to 260°C continuous use.
- Polyester tapes handle moderate heat but are more cost-effective.
- Glass cloth tapes combine high strength with thermal stability.
Common uses:
- High-temperature solder masking
- Component holding and bundling
- Electrical insulation in transformers and motors
Factors for Comparison
We’ll compare based on:
- Heat resistance (continuous & peak)
- Electrical insulation
- Adhesion strength
- Chemical resistance
- Durability
- Ease of application & removal
- Cost efficiency
Heat Resistance
- 3M 851 Tape: Performs well up to 130°C continuous, ideal for moderate heat exposure. Short bursts above this are manageable but not for prolonged high heat.
- Conventional PCB Tapes: Polyimide can handle up to 260°C continuously, making it superior for extreme heat processes.
Verdict: Conventional PCB tapes win for high-temperature soldering; 3M 851 is better for mid-range applications.
Electrical Insulation
- 3M 851: Strong dielectric strength, suitable for transformer and coil insulation.
- Conventional PCB Tapes: Polyimide and glass cloth also provide excellent insulation; some outperform polyester-based 3M 851.
Verdict: Tie, depending on specific material.
Adhesion Strength
- 3M 851: Silicone adhesive offers secure bonding and clean removal without residue.
- Conventional PCB Tapes: Adhesion varies; high-temp adhesives may be more aggressive, sometimes leaving residue.
Verdict: 3M 851 edges ahead for clean removal.
Chemical Resistance
- 3M 851: Resistant to solvents, oils, and most industrial chemicals.
- Conventional PCB Tapes: Polyimide is highly chemical-resistant; polyester may degrade faster in certain solvents.
Verdict: Slight edge to polyimide conventional tapes.
Durability Over Time
- 3M 851: Reliable for long-term insulation in moderate heat environments.
- Conventional PCB Tapes: Polyimide maintains integrity for years even under high heat.
Verdict: Polyimide wins for extreme environments.
Ease of Application & Removal
- 3M 851: Easy unwind, clean removal, minimal residue.
- Conventional PCB Tapes: May tear more easily or leave residue depending on adhesive type.
Verdict: 3M 851 is more user-friendly.
Cost Efficiency
- 3M 851: More affordable than high-grade polyimide tapes.
- Conventional PCB Tapes: Polyimide is costlier; polyester options are cheaper but with lower performance.
Verdict: For moderate heat needs, 3M 851 is more cost-effective.
Pros & Cons Table
| 3M 851 Tape |
Conventional PCB Tapes |
|---|---|
| Clean removal | Higher heat tolerance |
| Cost-effective | More chemical resistance |
| Good insulation | Long-term high-heat durability |
| Easy to apply | Wider range of materials |
| Limited heat rating | Can leave residue |
Best Use Cases
3M 851 Tape:
- Moderate heat applications
- Projects needing clean removal
- Cost-sensitive production runs
Conventional PCB Tapes:
- High-temp soldering and reflow
- Harsh chemical environments
- Long-term durability in extreme heat
Real-World Examples
- 3M 851: Used in transformer manufacturing for coil wrapping, where heat peaks briefly but doesn’t stay extreme.
- Polyimide Tape: Common in PCB wave soldering where boards face 260°C repeatedly.
Conclusion
When comparing 3M 851 tape and conventional PCB tapes, the winner depends on your heat exposure and budget.
- For extreme high heat and chemical resistance, polyimide or glass cloth tapes are better.
- For moderate heat, cost savings, and clean removal, 3M 851 is an excellent choice.
If you’re unsure, consider a hybrid approach — using 3M 851 in non-critical zones and polyimide in high-heat areas.