Semiconductor Case Electrode Nesting for Wire Height Reduction
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Solution Overview
Problem
Insertion molding of case electrodes in semiconductor devices does not provide sufficient firmness, leading to increased wire height, thickness, weight, and cost due to the need for additional sealing material and structural components.
Innovation Solution
A semiconductor device design featuring a recess on the case with a bent case electrode and a second holding portion inside the recess, which securely presses down the case electrode, reducing wire height while maintaining improved wire bonding properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If case electrodes are held on both inner and outer sides of wire joint portions, then wire bonding properties are improved, but wire height must be increased to avoid contact with holding portions
Solution Approach 1:
The second holding portion is nested within the recess formed on the upper face of the case, allowing the holding portion to be positioned inside the case structure rather than protruding outward. This nesting approach enables the holding portion to press down the case electrode effectively while maintaining a lower overall wire height, as the holding portion is contained within the case's recess rather than extending above it.
Solution Approach 2:
The design transitions from a two-dimensional planar arrangement to a three-dimensional structure by forming a recess on the upper face of the case and positioning the second holding portion within this recess. This dimensional change allows the holding portion to be positioned at a lower height level, enabling effective electrode holding while reducing the required wire height and overall device thickness.
2Reliability
If wire height is increased to prevent contact with holding portions, then wire bonding properties are improved, but device thickness, weight, and cost increase
Solution Approach 1:
By nesting the second holding portion within the recess of the case structure, the design eliminates the need for increased wire height, thereby reducing the overall device thickness and associated weight increases that would result from taller wires and higher sealing material levels.
3Reliability
If wire height is increased to prevent contact with holding portions, then wire bonding properties are improved, but device thickness increases
Solution Approach 1:
The second holding portion is nested within the recess formed on the upper face of the case, allowing it to press down the case electrode at a lower height position. This nesting configuration enables effective wire bonding without requiring increased wire height, thereby maintaining reduced device thickness.
Solution Approach 2:
By utilizing the vertical dimension through the recess structure, the design positions the second holding portion at a lower height level, enabling effective electrode holding while maintaining compact device thickness without requiring taller wires or increased sealing material.
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
The design securely holds the case electrode, enhancing wire bonding properties and reducing the semiconductor device's height, weight, and cost by minimizing the height of the second holding portion and allowing for reduced thickness and size.
Implementation Method 1
the case electrode is bent such as to fit into the recess
Implementation Method 2
a first holding portion pressing down the case electrode on the upper face of the case outside a joint portion where the wire is bonded to the case electrode; and a second holding portion pressing down the case electrode on the upper face of the case inside the joint portion
Data Source
AI summary
A case (6) surrounds a semiconductor chip (5). A case electrode (7) is attached to an upper face of the case (6). A wire (8) is connected to the semiconductor chip (5) and the case electrode (7). A first holding portion (10) presses down the case electrode (7) on the upper face of the case (6) outside a joint portion where the wire (8) is bonded to the case electrode (7). A second holding portion (11) presses down the case electrode (7) on the upper face of the case (6) inside the joint portion. A recess (12) is formed on the upper face of the case (6). The case electrode (7) is bent such as to fit into the recess (12). The second holding portion (11) is disposed inside the recess (12).