Semiconductor Electrode Extension via Segmented Grooves
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Solution Overview
Problem
The bonding strength between a semiconductor device and its mounting substrate is affected by the connection strength between the connection member and the electrode, which can be improved by increasing the connection area between them.
Innovation Solution
A method for manufacturing a semiconductor device involves forming first grooves on the back surface of a semiconductor wafer to create electrodes and second grooves that separate the wafer into chips, with the second grooves being wider and formed by dry etching, and using laser light to divide the metal film and protective film along dicing lines, creating an extension of the electrodes that increases the bonding surface area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the connection area between the electrode and the connection member is increased to improve bonding strength, then the bonding strength is improved, but the manufacturing complexity increases due to the need for additional groove formation processes
Solution Approach 1:
The electrode is segmented into multiple first electrodes by forming first grooves that divide the metal film, while the semiconductor wafer is segmented into chips by second grooves. This segmentation allows each electrode to have an extended configuration that increases the connection area with mounting substrates, thereby improving bonding strength without requiring a single large complex electrode structure
Solution Approach 2:
The first grooves are formed to extend in a direction substantially perpendicular to the second grooves, creating a grid-like pattern of electrodes. This dimensional arrangement increases the surface area of each electrode in multiple directions, providing larger connection areas for mounting substrates while maintaining a systematic manufacturing approach
2Area of stationary object
If laser light is used to divide the metal film along dicing lines to create electrode extensions, then the bonding surface area is increased, but damage is caused to the semiconductor wafer
Solution Approach 1:
The damage layer caused by laser irradiation is selectively removed by forming second grooves that extend from the front surface to the back surface of the semiconductor wafer. These grooves extract and eliminate the damaged regions while preserving the extended electrode structures, thereby recovering the semiconductor quality without compromising the increased bonding surface area
Solution Approach 2:
The laser-induced damage is converted into a beneficial process by using the damaged regions as guides for forming the second grooves. The damage locations precisely indicate where the grooves should be formed to separate the semiconductor wafer into chips, turning a harmful side effect into a useful marking mechanism for dicing
3Manufacturing precision
If dry etching is used to form second grooves to separate the wafer into chips, then the etching precision is improved, but the first electrodes are not selectively protected
Solution Approach 1:
The metal film and semiconductor wafer have different etching rates in the dry etching process. The first electrodes (metal film) are selectively protected due to their different material properties, which result in lower etching rates compared to the semiconductor wafer. This local quality difference allows the second grooves to be formed through the wafer while the electrodes remain substantially intact, achieving precise groove formation without requiring additional protective measures
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 method enhances the bonding strength of the semiconductor device by increasing the bonding surface area, reducing voids and burrs, and minimizing damage during the manufacturing process, resulting in improved connection reliability.
Implementation Method 1
irradiating laser light on the metal film provided on the back surface of the semiconductor wafer... scanning the laser light to divide the metal film along a dicing line
Implementation Method 2
forming a plurality of third grooves configured to divide the protective film into a plurality of etching masks on the front surface of the semiconductor wafer... formed by irradiating the protective film with laser light and scanning the laser light
Implementation Method 3
forming the plurality of second grooves by dry etching the semiconductor wafer
Data Source
AI summary
A semiconductor device includes a semiconductor part, a first electrode and a second electrode. The semiconductor part includes a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type. The first electrode is provided on a front surface of the semiconductor part. The second semiconductor layer is provided between the first semiconductor layer and the first electrode. The second electrode is provided on a back surface of the semiconductor part at a side opposite to the front surface. The second electrode includes an extension part extending outward from an outer edge of the back surface.