Two-Column Pad Structure for OLB Connection Verification
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Solution Overview
Problem
Existing display devices lack effective methods for inspecting the electrical connections between the substrate and the drive IC chip, particularly in ensuring proper outer lead bonding (OLB) processes, which can lead to defects if not accurately verified.
Innovation Solution
The display device incorporates a two-column connection pad structure with test pads and dummy pads, allowing for individual inspection of OLB connections using four-terminal sensing to measure resistance, ensuring that connections fall within a predetermined range for proper bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional single-column pad structure is used for mounting the drive IC chip, then the device complexity is reduced, but the ability to inspect and verify OLB connections individually is lost, leading to unreliable connection verification
Solution Approach 1:
The pad structure is divided into two separate columns: a first column with first pads and a second column with second pads. This segmentation allows independent inspection of OLB connections for each column through dedicated test pads, enabling reliable verification of bonding quality without requiring complex multi-point measurement systems.
2Measurement precision
If no dedicated test pads are provided for OLB inspection, then the ease of manufacture is improved, but the measurement capability for connection resistance is insufficient, making it impossible to detect bonding defects
Solution Approach 1:
Test pads are pre-configured in the pad structure during the manufacturing process. These test pads are electrically connected to the first and second pads through conductive patterns, enabling subsequent resistance measurements to be performed without additional manufacturing steps or complex external fixtures.
3Reliability
If traditional OLB mounting is used without individual column inspection capability, then the productivity is maintained, but the defect detection capability is insufficient, allowing bonding errors to pass undetected
Solution Approach 1:
The pad structure itself provides the inspection functionality through integrated test pads and conductive patterns. The structure enables self-verification of OLB connections by allowing resistance measurements to be performed directly on the mounted IC chip, eliminating the need for separate external inspection equipment or complex test fixtures.
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 approach enables reliable verification of OLB connections, allowing for early detection of defects and ensuring the integrity of electrical connections between the display panel and the driving circuit, thereby improving the quality and reliability of the display device.
Implementation Method 1
the connection resistance between the leads and pads excluding the noise resistance components can be measured by using four-terminal sensing
Data Source
AI summary
A display device including a display panel having panel pad units including a first panel pad unit having first pads arranged in a first column and a second panel pad unit having second pads arranged in a second column; a first member coupled to at least one of the first and second panel pad units; and a second member coupled to the first member and including a plurality of test pads, and wherein the first member includes lines electrically connecting a respective one of the plurality of test pads with a respective one of the first and second pads.