Flexible PCB Gold Finger Width Variation for Impedance

Solution Overview

Problem

The increasing resolution of liquid crystal displays necessitates a higher number of gold fingers on flexible printed circuit boards, leading to size and cost issues, as well as impedance matching problems, as the number of gold fingers increases.

Innovation Solution

A flexible printed circuit board design with varying widths and spacings of gold fingers, where first gold fingers for differential signals are wider and spaced differently than second gold fingers for other signals, allowing for increased gold fingers without enlarging the board size, thereby addressing impedance matching challenges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the number of gold fingers is increased to satisfy higher resolution requirements, then the signal transmission capability is improved, but the board size must be increased and impedance matching becomes difficult

Engineering Contradiction:

Improvenumber of gold fingersVSAvoidboard size

Core Design Contradiction:

Quantity of substanceVSArea of stationary object

Solution Approach 1:

The patent applies local quality by making different gold fingers have different widths based on their signal transmission needs. First gold fingers transmitting differential signals are made wider than second gold fingers transmitting other signals. This localized differentiation allows optimal impedance control for each signal type while maximizing the number of gold fingers within the fixed board area.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If the number of gold fingers is increased to satisfy higher resolution requirements, then the signal transmission capability is improved, but the impedance matching becomes difficult

Engineering Contradiction:

Improvenumber of gold fingersVSAvoidimpedance matching

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by making different gold fingers have different widths based on their signal transmission needs. First gold fingers transmitting differential signals are made wider than second gold fingers transmitting other signals. This localized differentiation allows optimal impedance control for each signal type while maximizing the number of gold fingers within the fixed board area.

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If the number of gold fingers is increased to satisfy higher resolution requirements, then the signal transmission capability is improved, but the manufacturing cost is increased

Engineering Contradiction:

Improvenumber of gold fingersVSAvoidmanufacturing cost

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent applies local quality by making different gold fingers have different widths based on their signal transmission needs. First gold fingers transmitting differential signals are made wider than second gold fingers transmitting other signals. This localized differentiation allows optimal impedance control for each signal type while maximizing the number of gold fingers within the fixed board area.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS9804457B2Flexible printed circuit board and liquid crystal display

Publication Date: 2017.10.31 TCL CHINA STAR OPTOELECTRONICS TECHNOLOGY CO LTD

AI summary

The disclosure is related to a flexible printed circuit board. The flexible printed circuit board comprises a connecting area and a plurality of gold fingers disposed inside the connecting area, wherein the widths of the gold fingers are different. By the above manner, the disclosure is able to increase the number of the gold fingers without changing the size of the flexible printed circuit board so as to solve the impedance matching problem of the gold fingers of the flexible printed circuit board.