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Which High Temperature Tape Is Best for Brown Circuit Board Applications |https://www.lvmeikapton.com/

Source: | Author:Koko Chan | Published time: 2025-05-21 | 46 Views | Share:



Which High Temperature Tape Is Best for Brown Circuit Board Applicationshttps://www.lvmeikapton.com
AbstractThis article compares the performance of different high-temperature tapes for brown circuit boards, focusing on their heat resistance, flame retardancy, and adhesive properties. By analyzing the characteristics of PI (Polyimide) tape, black/transparent PET tape, and other variants, it evaluates their suitability for protecting critical components like gold fingers during soldering processes at 260°C. Practical cases from HP and Apple laptop applications are also explored to demonstrate real-world usage scenarios.
Keywords: Brown circuit board, lvmeikapton insulating electrical tape, PI material high-temperature resistant 300 tape, Adhesive PET material high-temperature tape
1. IntroductionIn modern electronics, brown circuit boards (PCB) play a vital role in device functionality. Their reliability heavily depends on the protection of sensitive areas, particularly gold fingers, which require robust insulation and thermal resistance during manufacturing and operation. High-temperature tapes are essential materials for these tasks, with PI and PET tapes being two prevalent options. This study aims to compare their performance, focusing on key parameters like temperature resistance, adhesive strength, and compatibility with gold finger protection processes.
2. Performance Comparison: PI vs. PET Tapes
2.1 Material Composition and Properties
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PI (Polyimide) Tape: Manufactured from Polyimide film, PI tape excels in high-temperature environments. It withstands temperatures up to 260°C (some variants reach 280°C) without deforming, melting, or leaving residue. Its superior thermal stability, chemical resistance (to acids, alkalis, and solvents), and electrical insulation make it ideal for harsh conditions. The tea-colored appearance aids in visual identification during assembly.
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Key Features:
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Temperature range: 260–280°C
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Thickness options: 50U, 75U, 100U
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Adhesion: Moderate to high (acrylic-based adhesive)
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Electrical insulation: ≤1016 Ω/sq
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PET (Polyethylene Terephthalate) Tape: PET tapes come in black or transparent variants, featuring excellent dimensional stability and mechanical strength. While their standard temperature resistance ranges from -10°C to 100°C, specialized high-temperature PET variants can withstand up to 150°C. Black PET tapes offer superior light shielding (≥99.9%遮光率) and are widely used for optical component protection.
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Key Features:
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Temperature range: -10°C to 150°C (high-temp variants)
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Thickness: Typically 65μm
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Adhesion: Acrylic adhesive (white/black faces with different strengths)
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Light shielding: Black face for optical applications
Table 1: Comparative Properties of PI vs. PET Tapes
Parameter
PI Tape (lvmeikapton)
PET Tape (High-Temp Variant)
Max Temperature
260–280°C
150°C (max)
Adhesion Strength
1.5–2.0 kg/in
1.7–1.9 kg/in (black face)
Insulation Resistance
≥1016 Ω/sq
≥1012 Ω/sq
Chemical Resistance
Excellent (wide range)
Good (resistant to most solvents)
Flexibility
High
Moderate
Light Shielding
N/A
Black variants: ≥99.9%
2.2 Adhesive Performance AnalysisPI tapes utilize acrylic or silicone-based adhesives, ensuring strong bonding with minimal residue after removal. Their adhesive properties balance firm adhesion and easy reworkability, crucial for PCB repair. PET tapes, especially black variants, offer differentiated adhesion strengths (e.g., white face for bonding, black face for light blocking), but their adhesion may degrade faster at extreme temperatures compared to PI.
3. PCB Gold Finger Protection: Process RequirementsProtecting gold fingers (electrical contacts) on brown PCBs demands stringent processes to ensure durability and reliability:
1. 
Material Selection: Prioritize hard gold plating (Au compounds) to enhance wear resistance.
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Edge Beveling: 45° chamfers prevent stress concentration and improve contact stability.
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Solder Mask开窗: Full solder mask opening around gold fingers allows direct tape application.
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Copper Removal: Inner layers require "copper skimming" (≥3mm width) to reduce impedance differences.
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Temperature Protection: During 260°C soldering, tapes must prevent thermal damage to contacts.
4. Case Studies: HP and Apple Laptop Applications
4.1 HP Laptop Mainboard ProtectionHP’s high-end laptops utilize PI tape for gold finger protection in the following manner:
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Application: PI tape (100U thickness) covers gold fingers during wave soldering.
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Benefits:
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Withstands 280°C peak temperatures without delamination.
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Shields against solder splash while maintaining electrical integrity.
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Post-soldering, tape removal leaves no residue, ensuring contact cleanliness.
4.2 Apple’s Optical Module InsulationApple integrates PET tape for dual functions in its laptops:
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Black PET Tape: Secures LED backlight modules, blocking light leakage while providing mechanical stability.
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Clear PET Tape: Insulates secondary connectors, balancing transparency and heat resistance (up to 150°C).
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Design Considerations: PET’s high reflectivity (white face: 88%) enhances backlight efficiency, while black variants prevent ghosting.
5. Practical Considerations for Tape SelectionWhen choosing tapes for brown PCBs, consider:
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Temperature Profile: For >260°C processes (e.g., wave soldering), PI is non-negotiable.
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Functionality: PET excels in light management or moderate-heat zones.
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Cost vs. Performance: PI costs more but offers long-term reliability in critical areas.
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Reusability: PI’s easier reworkability benefits prototyping phases.
6. ConclusionFor brown circuit board applications, PI tape dominates in high-temperature, high-reliability scenarios, particularly protecting gold fingers during extreme soldering. Its thermal robustness, chemical resistance, and electrical insulation justify its premium cost. Conversely, PET tapes shine in optical shielding and moderate-temperature environments, offering cost-effective solutions for non-critical zones. When designing PCB protection strategies, a hybrid approach—leveraging PI for gold fingers and PET for auxiliary components—optimizes performance and cost.