Factory Customized FR-4 Single-sided Printed Electronic Circuit Board for Industrial Control Applications

1、Core process technology

1. Standardized process flow

Graphic transfer (key steps):

Screen printing: lowest cost, line width ≥ 0.25mm (suitable for paper substrates)

LDI exposure: accuracy ± 0.1mm, line width ≥ 0.08mm (recommended for FR-4)

Etching control:

Etching solution: FeCl ∝ or acidic copper chloride

Side corrosion rate ≤ 15%, concentration/temperature/spray pressure needs to be controlled

Surface treatment:

Applicable scenarios for the retention period of process cost
HASL Tin Spray Minimum 6 Months Consumer Electronics
OSP low 6-month industrial board (requiring rapid SMT)
High reliability requirement for 12 months in tin deposition

2. Technological innovation

Die cutting instead of etching:

Copper foil substrate is directly stamped and formed without chemical waste liquid

Efficiency increased by 50%, but line width limit ≥ 0.3mm

Thick copper design:

Localized 2oz copper foil etching, supporting 5A current (power module)

2、 Core Advantage Analysis

1. Economic advantages (compared to double-sided panels)

Indicator single panel double-sided panel reduction
Board cost ¥ 20-50/㎡ ¥ 50-100/㎡ 50-60%
Production cycle 1-3 days (batch) 3-5 days (batch) 40%
Repair cost<$0.5/time>$2/time 75%

2. Performance and reliability

Low failure rate:

No risk of interlayer short circuit, CAF (conductive anode wire) occurrence rate=0

Bending strength: FR-4>400MPa (twice the strength of the paper substrate)

Environmental adaptability:

FR-4 can withstand cycling from -40 ℃ to 125 ℃, with a damp heat test (85 ℃/85% RH) for 1000 hours

Flame retardant rating: 94V-0 (10 second self extinguishing)

3、 Application Fields and Typical Cases

1. Consumer electronics (accounting for 65%)

Product substrate type, technical solution, cost
Air conditioner remote control paper substrate (FR-1) single key circuit+OSP processing<$0.2 per piece
LED bulb light driven aluminum substrate non isolated solution+thick copper design<$0.5/piece
Electronic scale motherboard FR-4 4-layer analog circuit simplified version $0.3-0.5/piece
2. Industrial control (accounting for 25%)
PLC relay module:

FR-4 single-sided+OSP, resistant to 100000 insertions and removals (IEC 60664)

Temperature and humidity sensor:

Large area copper laying for heat dissipation, working in the full temperature range of -40 ℃~85 ℃

3. Automotive Electronics (Special Scenarios)
Window switch: High Tg FR-4 (Tg ≥ 150 ℃), resistant to engine compartment 85 ℃

Disable scenario: ECU/ABS and other high-frequency core systems

4、 Limitations and Solutions

Effect of defect solution
Low wiring density jumper/0 Ω resistor jumper increases wiring flexibility by 30%
High frequency loss>100MHz, switch to double-sided board insertion loss from>3dB to<1dB
Cooling bottleneck with embedded aluminum heat sink and thermal conductive hole design, temperature drop of 10-15 ℃ (5W scenario)