IC Bondwire Continuity Detection Using Capacitive Self-Test

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Solution Overview

Problem

Conventional testing methods for integrated circuits with multiple bondwires fail to detect incorrectly bonded wires, leading to sub-optimal performance due to electrical continuity being maintained by correctly bonded wires, which is not detected during standard electrical tests.

Innovation Solution

Incorporation of self-testing circuitry that supplies voltage or current to pads and uses detection modules to determine electrical continuity between pads, employing low-pass filters and capacitive couplings to filter out signals from reaching active elements, and ESD protection devices to ensure reliable detection of bondwire integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple bondwires are used to connect the transceiver device to RF pin, then circuit inductance and resistance are reduced and reliability is increased, but conventional testing cannot detect broken bondwires since electrical continuity is maintained through other bondwires

Engineering Contradiction:

ImprovereliabilityVSAvoiddifficulty of detecting broken bondwire

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

An active element (such as a transistor) is introduced as an intermediary between the bondwires. The active element's node is capacitively coupled to both bondwires, and by applying a voltage or current to one bondwire and detecting at the other, the active element enables detection of broken bondwires through its electrical characteristics while maintaining the redundancy benefit of multiple bondwires

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces conventional direct electrical continuity testing with an active element-based detection system. Instead of simply measuring resistance or continuity between pads, the system uses an active element with capacitive coupling to detect bondwire integrity, enabling detection of broken bondwires that would otherwise be undetectable through traditional methods

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If multiple bondwires are used for UWB applications, then system performance is improved, but fabrication defects such as improperly bonded bondwires cannot be readily detected

Engineering Contradiction:

Improvesystem performanceVSAvoiddetection of fabrication defects

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The detection circuit is configured to test bondwire integrity before final packaging and deployment. By incorporating the active element and detection circuitry into the integrated circuit structure, the system enables preliminary detection of bondwire defects during or after assembly but before the product reaches the customer, allowing for quality control at an optimal point in the manufacturing process

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If conventional electrical continuity testing is used, then testing is simple, but broken bondwires are not detected leading to sub-optimal performance in the field

Engineering Contradiction:

Improveease of testingVSAvoidperformance in field

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The integrated circuit incorporates self-testing capability through the active element and detection circuitry. The circuit can autonomously test its own bondwire connections by applying test signals and detecting responses, enabling built-in quality verification without requiring external testing equipment or complex manufacturing processes

Inventive Principle:

Principle #25Self-service

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

Enhances the ability to detect broken bondwires, thereby maintaining optimal active element performance while ensuring reliable electrical connectivity and redundancy, improving the detection sensitivity and reliability of integrated circuits.

Implementation Method 1

an active element having a node that is capacitively coupled to the first and second pads

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

The voltage or current source and / or the detection module comprises a low-pass filter circuit. The low-pass filter circuit may be a resistor-capacitor, RC, filter circuit

Methodology Applied

Scientific EffectLow-pass filtering: Filter (electronic)

Data Source

PatentEP4063878B1Integrated circuit and associated method

Publication Date: 2026.05.06 NXP BV

Figure 1~2
Figure 3a~3b
Figure 4

AI summary

The disclosure relates to an integrated circuit (300) and associated method and packaged integrated circuit. The integrated circuit comprises a first pad (302); a second pad (304); an active element (306) having a node (308) that is capacitively (340, 342) coupled to the first and second pads; a voltage or current source (310) connected to the first pad; and a detection module (312) connected to the second pad and configured to determine an electrical continuity between the second pad and the first pad.