Customized 94V0 High Flame Retardant Single-sided Printed Circuit Board for Application in Automotive Electronics

1、 Detailed explanation of process technology

1. Substrate and flame retardant properties

Substrate composition:
Using fiber paper (wood pulp/cotton pulp) as the core material, impregnated with phenolic resin containing flame retardants (such as brominated epoxy resin), covered with electrolytic copper foil (1oz/35 μ m standard), certified by UL 94V-0 (self extinguishing within 10 seconds of vertical combustion) .

Key parameters:

Electrical strength: ≥ 1.6kV/mm (ensuring high voltage isolation)

Peel strength: ≥ 1.5N/mm (copper foil adhesion)

Thermal shock: Tested at 288 ℃/10 seconds (without delamination) .

2. Core process flow

Key points of process technology: precision control
Graphic transfer screen printing with corrosion-resistant ink (line width ≥ 0.2mm), replacing LDI exposure to reduce costs with a line width tolerance of ± 0.1mm
Etching and stripping FeCl ∝/H ₂ O ₂ acidic etching → NaOH solution stripping side etching ≤ 15 μ m
Drilling die punching process (aperture ≥ 0.4mm) or CNC drilling, with an efficiency 50% higher than mechanical drilling and a hole position accuracy of ± 0.05mm
Surface treatment: HASL spray tin (low cost) or OSP (environmentally friendly lead-free), solder resistant to 235 ℃ for 3 seconds, solder thickness 1-25 μ m
Solder mask and forming silk screen solder mask ink (hardness>5H) → digital V-cut (angle 30 °/45 °, depth plate thickness 2/3) solder mask bridge width ≥ 0.1mm .

3. Technological innovation and limitations

Innovation point: High efficiency molding through die punching: supports batch punching, with a monthly production capacity of 20000 square meters (such as LED light boards).
Environmental Upgrade: Halogen free formula (bromine content<900ppm), compliant with RoHS Directive .

limitations:
Weak heat resistance: Tg ≈ 105 ℃, prone to deformation at high temperatures (FR-4 should be used for scenarios>130 ℃) .
High frequency loss: dielectric constant Dk> 5.0@1MHz ， The signal attenuation of 100MHz is significantly .

2、 Core Advantage Analysis

1. Economy and efficiency

Indicator 94V0 single panel comparison FR-4 single panel advantage
Board cost 20-30 yuan/㎡ 50-80 yuan/㎡ ↓ 50% or more
Urgent production cycle, 24-hour delivery of samples requires 48 hours to improve efficiency by 50%
Processing adaptability supports punching and forming, requiring mechanical drilling suitable for large-scale production

2. Performance and reliability

Flame retardant safety: UL 94V-0 certification, self extinguishing within 10 seconds of an open flame, reducing fire risk by 15%.

Environmental tolerance:

Resistant to 85 ℃/85% RH humidity and heat (industrial PLC module lifespan>10 years) .

Ionic cleanliness<1.56 μ g/cm ², reducing electrochemical migration by 1.

Easy maintenance: The fault point can be visually located, and the repair time for flying wires is less than 5 minutes.

3. Sustainability

Material recovery rate>60%: The paper substrate is biodegradable, and the copper foil recovery rate is>90%.

No heavy metal pollution: OSP surface treatment replaces gold deposition, reducing wastewater discharge by .

3、 Application Fields and Typical Cases

1. Consumer electronics (accounting for 70%)

LED lighting driver:

Bubble lamp/T8 tube substrate (adopted by 70% of global manufacturers), equipped with aluminum heat sink to solve temperature rise, cost<50% of FR-4 .

Home appliance control board:

Air conditioner remote control, rice cooker timer (single button circuit design), monthly production capacity of 20000 ㎡ .

2. Industrial control (accounting for 25%)

Performance verification of application scenario technical solutions
PLC relay module OSP processing+locally thick copper design resistant to 100000 insertions and removals (IEC 60664)
Large area grounding design of temperature and humidity sensor -40 ℃~85 ℃ full temperature range accuracy ± 2%

3. Automotive Electronics (Special Adaptation)

Low voltage non safety module: window switch, seat heating controller (to avoid high temperature areas in the engine compartment) .

Disabled scenario: High frequency core systems such as ECU/ABS (insufficient temperature resistance and signal integrity).

4、 Limitations and coping strategies

Effect of defect solution
Insufficient heat resistance>130 ℃, switch to high Tg FR-4 to avoid reflow soldering deformation
Weak high-frequency performance>100MHz circuit with double-sided aluminum substrate signal insertion loss reduced to<3dB
Adding fiberglass reinforcement sheets to critical areas with low mechanical strength increases bending strength by 40%