Circuit Board Having Shielding Planes with Varied Void Opening Patterns for Controlling the Impedance and the Transmission Time of Differential Transmission Lines Chi-Kuang Hwang Dept. of Electrical Engineering Chung-Hua University

Patents Inventors – Gwun-Jin Lin – Chi-Kuang Hwang – Ching-Cheng Tien USA (4) Japan Korea Europe Taiwan China

Introduction Structure – Shielding Planes – Varied Void Opening Patterns – Controlling the Impedance and the Transmission Time – Differential Transmission Lines Differential Transmission Lines – High Frequency Transmission Rate (Differential Transmission Lines) – High Noise Rejection capability – Low EMI – Low Voltage

Characteristic Impedance Coaxial Cable Two-Wire Transmission Line D a b

Impedance Matching Common mode 50Ω Differential Mode 100 Ω Virtual Ground

Slow Wave Effect Solid Ground – Fast Transmission Time Void Opening Pattern – Slow Transmission Time Similar to 100m Race with or without Hurdles

Mechanical Properties Symmetric – Fatigue Test (20000 Times) 4000 Times (Taiwan) 7000 Times (Japan) Times Manufacturing – Single Layer Double Access

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Applications Computers and Communications – Notebook – Cellular Phone – PDA Display – LCD Testing Cables

Connectors Testing Cables Standard Cables Non-Adhesive Flexible Cables – Chip On Film (COF) Single Layer Double Access