Pressure-Contact Electrode Layout for Uniform Chip Contact Resistance
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Solution Overview
Problem
Pressure-contact semiconductor devices face issues with local pressure cracking of semiconductor chips and varying contact resistance due to pressure variance, leading to reduced reliability and increased module size when attempting to suppress electrical contact between intermediate electrodes and semiconductor chips.
Innovation Solution
The device incorporates a first intermediate electrode with a smaller facing surface than the main electrode, featuring a protective region and a connection region surrounded by the protective region, with partially formed conductor films in the connection region to ensure balanced pressure distribution and prevent electrical contact at the outer peripheral portion without increasing chip area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer peripheral portion of the front surface intermediate electrode is pressurized to suppress electrical contact, then reliability is improved, but the semiconductor chip cracks and breaks due to intensive local pressure
Solution Approach 1:
The patent applies different properties to different regions of the intermediate electrode's facing surface. The connection region (central portion) has conductor films formed to enable electrical contact, while the protective region (outer peripheral portion) has no conductor films to prevent electrical contact and suppress cracking. This local differentiation allows the outer periphery to be pressurized without causing chip damage, while maintaining necessary electrical contact in the center.
2Reliability
If a buffer area with pedestal portion is provided to suppress electrical contact, then reliability is improved, but chip size must be increased leading to larger module size
Solution Approach 1:
The patent segments the facing surface of the intermediate electrode into two distinct regions: a connection region in the central portion where conductor films are formed for electrical contact, and a protective region in the outer peripheral portion where no conductor films are formed to prevent electrical contact. This segmentation achieves electrical contact suppression without requiring additional buffer areas, thereby maintaining compact chip size.
3Reliability
If intensive pressure is applied to the outer periphery of the intermediate electrode, then electrical contact suppression is achieved, but contact resistance varies due to pressure variance
Solution Approach 1:
The patent creates different surface characteristics in different regions of the intermediate electrode. The connection region has conductor films that provide stable electrical contact with consistent contact resistance, while the protective region has no conductor films and is designed to prevent electrical contact entirely. This local quality differentiation ensures that pressure variance does not affect contact resistance uniformity, as each region is optimized for its specific function.
Data Source
AI summary
An object of the present invention is to suppress electrical contact between an outer peripheral portion of an intermediate electrode and a front surface electrode of a semiconductor chip without increasing the area of the semiconductor chip. A facing surface of the first intermediate electrode facing a first main electrode is smaller than a facing surface of the first main electrode facing the first intermediate electrode, and has an outer peripheral protective region and a connection region surrounded by the protective region. A pressure-contact semiconductor device includes a plurality of first conductor films partially formed in the connection region, and a first insulating film formed in regions in the connection region where no first conductor films are formed and in the protective region.