Display Driver IC Terminal Configuration for Voltage Drop Reduction
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Solution Overview
Problem
Conventional display devices with built-in charge pump type DC/DC converters experience increased wiring resistance due to uniform terminal widths and pitches, leading to voltage drop and complex wiring paths, which complicates the reduction of contact resistance and overall display quality.
Innovation Solution
A display device with non-uniform terminal arrangements, where terminals connected to the power supply circuit have wider widths and varying intervals, and optionally feature a transparent conductive film or slits/window apertures to reduce contact resistance and simplify the wiring path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If uniform terminal widths are used for ease of design, then manufacturing simplicity is improved, but wiring resistance increases leading to voltage drop
Solution Approach 1:
The patent applies local quality by making terminal widths non-uniform based on their specific function. Power supply terminals have larger widths to reduce contact resistance and voltage drop, while signal terminals maintain smaller widths. This localized differentiation optimizes electrical performance at critical points without requiring complete redesign of all terminals.
Solution Approach 2:
The patent changes the parameter of terminal width from a uniform value to variable values based on functional requirements. By adjusting the width parameter of power supply terminals specifically, the patent reduces contact resistance and minimizes voltage drop in the power supply path while maintaining design feasibility.
2Device complexity
If uniform terminal pitches are used, then design simplicity is improved, but wiring path becomes complex and contact resistance increases
Solution Approach 1:
The patent applies asymmetry by using non-uniform terminal pitches where the interval between power supply terminals differs from that of signal terminals. This asymmetric arrangement simplifies the wiring path for power supply by positioning terminals optimally, reducing the number of wiring layers needed and minimizing contact resistance at critical power connection points.
3Object-affected harmful factors
If ITO film is formed on terminal surfaces for oxidation prevention, then protection is improved, but contact resistance increases
Solution Approach 1:
The patent applies local quality by selectively forming ITO films only on signal terminals that require oxidation protection, while omitting ITO films from power supply terminals where contact resistance must be minimized. This localized application maintains protection where needed while avoiding the harmful effect of increased contact resistance in power supply paths.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively reduces contact resistance and minimizes wiring resistance by optimizing terminal dimensions and intervals, enhancing display quality by maintaining voltage levels and simplifying the wiring path.
Implementation Method 1
a charge pump in the driver IC charges the voltage from the driver IC via the wirings to a boost capacitor mounted on the FPC
Implementation Method 2
driver IC 101 and wiring 3 are electrically connected to each other by performing pressure bonding with anisotropically conductive tape 9 lied between bump 10 and ITO film 8
Implementation Method 3
ITO (Indium Tin Oxide) film 8 that is a transparent conductive film for preventing oxidation of terminal surfaces is formed on wiring 3
Implementation Method 4
A display device uses a structure in which a glass substrate, a driver IC, and a flexible substrate are joined by thermal pressure bonding method
Data Source
AI summary
Driver IC 1 including a built-in charge pump power supply is mounted on display panel 5. Among wirings connected to driver IC 1, the width of FPC mounting pad 4 of connection wiring 3 leading to a driver built-in power supply is widened as compared with pads 4 of other wirings 2. In addition, a portion of terminal intervals of a terminal array of FPC mounting pad 4 is widened as compared with other terminal intervals so that a wiring path from pad 4 to driver IC 1 is reduced. Similar terminal widths and terminal intervals are adopted for terminal 6 on the side of flexible substrate 7 electrically connected to FPC mounting pad 4 by pressure bonding.