Capacitive Defect Detection Module for Non-Contact TGV Testing
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Solution Overview
Problem
Conventional defect detection methods for circuit boards and glass substrates cause irreversible damage to copper wires and lack accurate, non-destructive detection of Through Glass Via (TGV), leading to decreased product yield and reliability.
Innovation Solution
A defect detection module comprising a signal emitting module, transmitting and receiving capacitive electrodes, and a signal processing module that processes signals through equivalent capacitance to detect defects non-destructively, using different dielectric coefficients to differentiate signals from air and substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a metal electrode on a detecting probe is used to directly contact the copper wires on the circuit board for defect detection, then the detection method is simple and direct, but the copper wires are easily damaged causing irreversible damage and decreased product yield
Solution Approach 1:
The patent replaces the mechanical contact-based detection method with a non-contact electromagnetic signal transmission method. Instead of using a metal electrode to physically touch the copper wires, the invention uses electromagnetic signals that can penetrate the substrate to detect defects without mechanical contact, thereby eliminating wire damage while maintaining detection capability
Solution Approach 2:
The patent introduces an electromagnetic signal as an intermediary to transfer information from the detection side to the target side. The signal travels through the substrate and interacts with the copper wires indirectly, allowing defect detection without direct physical contact between the probe and the wires
2Measurement precision
If conventional image recognition and copper plating methods are used to detect Through Glass Via (TGV), then detection can be performed, but image recognition has low accuracy affecting product yield and copper plating adds additional cost
Solution Approach 1:
The patent replaces conventional image recognition and copper plating methods with electromagnetic signal-based detection. This substitution provides higher detection accuracy for TGV by measuring electrical properties directly, while eliminating the need for additional copper plating processes and reducing reliance on less accurate image recognition techniques
Solution Approach 2:
The patent detects TGV by measuring changes in electrical parameters (such as impedance or capacitance) caused by the presence or absence of via holes. This parameter-based detection approach provides higher accuracy compared to image recognition while avoiding the need for copper plating, thus reducing both improving measurement precision and ease of manufacture
3Reliability
If metal probe is used to input signals to copper wires on circuit board or glass substrate for circuit testing, then circuit operation can be confirmed, but the soft copper wires are easily damaged resulting in irreversible damage
Solution Approach 1:
The patent replaces the mechanical probe contact method with non-contact electromagnetic signal transmission. The electromagnetic signals can penetrate the substrate and interact with the copper wires to confirm circuit operation without requiring physical contact, thereby eliminating the harmful mechanical damage to the soft copper wires while maintaining the ability to verify circuit functionality
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
Enables high-precision, non-destructive defect detection on high-speed circuit glass substrates, enhancing product yield and reliability by distinguishing between successful and unsuccessful drilling without physical contact.
Implementation Method 1
the signal emitting module generates a first signal; the first signal is transmitted and travels through the transmitting electrode, a medium and the receiving electrode to generate a second signal
Implementation Method 2
the transmitting electrode, the medium and the receiving electrode form an equivalent capacitance including a capacitance of the medium
Implementation Method 3
Due to the different dielectric coefficients of the air in the via hole and the substrate, the strength of the second signal received by the capacitive receiving electrode is different
Data Source
AI summary
A defect detection module comprises a signal emitting module, a transmitting electrode, a receiving electrode, and a signal processing module. The signal emitting module of the present invention emits a first signal. The first signal passes through the transmitting electrode, a medium and the receiving electrode to generate a second signal. The transmitting electrode, the medium and the receiving electrode forms a capacitance value corresponding to the medium which may be solid or comprising air. The signal processing module processes the second signal to obtain a detection result.