Comparison between YFLEX and through-hole FPC
Through-hole soldering
Bump lamination
Bump Lamination Process
2-layer double-sided circuit board manufacturing process
Layer Structure of double sided YFLEXTM
Example of YFLEX structure
Materials
- Substrate
- Liquid Crystal Polymer (25 or 50 µm)
- Conductor
- Copper (12,18,or 35µm)
- Bump
- Silver Filled Resin
- Cover Lay
- Thermoset Resist, Photo Sensitive Resist, Polyimide
Design Rules
| Standard | Minimum | |
|---|---|---|
| Width (Trace/Space) | 60/60µm | 30/30µm |
| Bump Diameter | 250µm | 150µm |
| Land Diameter | 400µm | 250µm |
| Maximum Current per Bump | 100mA | 50mA |
| Suerface Process |
Au Flash Plating Au Bonding Plating |
|
LCD moisture absorption and dielectric constact data
High humidity decreasing rate of voltage proof (Vx)
Dielectric constant
Expansion rate
LCD test data
| Conditions | Results | |
|---|---|---|
| Resistance per a bump | Room temperature/humidity | 6mΩ or less |
| Temperature cycle test | - 55°C to + 125°C, 1000cycle | Resistance change: Within 6% |
| High temperature storage test | + 125°C, 1000h | Resistance change: Within 6% |
| Low temperature storage test | - 40°C, 1000h | Resistance change: Within 6% |
| High temperature/humidity test | 85°C, 90%RH, 1000h | Resistance change: Within 6% |
| Ion migration test | 40°C, 90%RH, 60VDC, 1000h | No insulation damage |
| Peeling test | 90°peels (Copper t=35µm) | >0.8KN/m |
| Soldering thermal test | 260°C, 20sec | No damage |
| Dielectric constant (1GHz) | Bridge method* | 2.8 |
| Dielectric dissipation factor (1GHz) | Bridge method* | 0.0025 |
| Moisture absorption | 23°C, 24h* | <0.04% |
| Thermal expansion | TMA method* (Thermo-Mechanical Analysis) | x: 12ppm/°C y: 16ppm/°C z: Approx. 100ppm/°C |
* Measuring method: JIS C 6481-1996
- The data are for reference only. Yamaichi Electronics Co., Ltd. does not gurantee the above-mentioned values.