Semiconductor Wire Bond Inspection Using Pulse Sense Voltage
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Solution Overview
Problem
Existing methods for detecting wire bonding deterioration in semiconductor devices mounted on circuit boards suffer from low accuracy due to temperature changes caused by self-heating, making it difficult to determine resistance changes and thus failing to reliably assess the bonding state.
Innovation Solution
An inspection method involving a pulse signal input to the gate terminal, detecting the sense voltage between the sense source and source terminals, and comparing it with a threshold voltage at the signal turn-off time, while the semiconductor device is mounted on a circuit board, using exposed portions of leads to accurately determine the bonding state without being affected by temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resistance value monitoring is used to detect wire bonding deterioration in a mounted semiconductor device, then the bonding state can be detected in actual use, but the accuracy is low due to temperature changes from self-heating
Solution Approach 1:
The patent applies periodic action by using pulse signals to periodically apply voltage to the gate terminal and measuring the sense voltage at specific moments (turn-off time). This periodic measurement approach allows detection of wire bonding state without continuous power application, thereby minimizing self-heating effects while maintaining detection capability.
Solution Approach 2:
The patent uses preliminary action by pre-setting a threshold voltage value that represents the acceptable bonding state. This threshold is established before actual operation, allowing quick comparison and detection during pulse measurements without requiring complex real-time analysis, thus improving detection accuracy while minimizing measurement time and heat generation.
2Reliability
If continuous voltage monitoring is performed to detect bonding deterioration, then the bonding state can be monitored in real-time, but self-heating occurs causing temperature changes that interfere with measurement accuracy
Solution Approach 1:
The patent implements periodic action by applying voltage only in pulse form rather than continuously. The pulse signal is applied intermittently, and measurements are taken at specific moments (at the turn-off time), which allows real-time monitoring capability while significantly reducing the overall power dissipation and self-heating of the semiconductor device.
Solution Approach 2:
The patent applies skipping by rushing through the measurement process at the turn-off time of the pulse signal. Instead of continuously monitoring and allowing temperature to rise, the measurement is quickly completed at a specific moment in the pulse cycle, minimizing the duration of power application and thus reducing temperature increase.
3Measurement precision
If resistance change measurement is used to detect bonding deterioration, then the bonding state can be assessed, but it is difficult to determine the change in resistance due to temperature change
Solution Approach 1:
The patent uses periodic action with pulse signals to create a measurement system that inherently separates bonding resistance measurement from temperature effects. By measuring at the turn-off time when the pulse ends, the system captures voltage information that reflects bonding state without the confounding influence of temperature-dependent resistance changes that occur during continuous operation.
Solution Approach 2:
The patent introduces an intermediary approach by using the sense voltage measurement as an intermediate parameter that indirectly reflects bonding state. Instead of directly measuring resistance (which is temperature-dependent), the system measures voltage at a specific moment in the pulse cycle, which serves as an intermediary indicator that is less sensitive to temperature changes.
Data Source
AI summary
A semiconductor device includes: a semiconductor element having an element main surface and first and second electrodes arranged on the element main surface; a first lead mounting the semiconductor element thereon; a second lead electrically connected to the first electrode; a third lead electrically connected to the second electrode; first connecting portions bonded to the first electrode and the second lead; and a sealing resin covering the semiconductor element, wherein the sealing resin includes a resin main surface facing the same side as the element main surface and a resin side surface connected to the resin main surface, the second lead includes a portion exposed from the sealing resin, the third lead includes a portion exposed from the sealing resin, and the exposed portion of the second lead includes a portion located on a side of the resin main surface with respect to the exposed portion of the third lead.