Premolded Clip Structure for Power MOSFET Alignment
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Solution Overview
Problem
Conventional semiconductor die packaging methods using clips for power MOSFETs face inefficiencies in processing and cost, with inconsistencies in aligning clips to the die regions and difficulties in making simultaneous connections.
Innovation Solution
The use of premolded clip structures where the first and second clips are molded together with the molding material, allowing for simultaneous and uniform solder connections by fixing the relative positions of the clips before attachment, and employing partial etching to define solderable contact areas for improved compatibility and locking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separate clips are mounted using a pick-and-place tool with two vacuum holes, then connections between electrical terminals and leadframe structure can be provided, but processing efficiency is reduced and processing costs increase
Solution Approach 1:
The patent combines multiple separate clips into a single integrated clip structure that can be mounted in one operation. The integrated clip includes multiple contact portions that simultaneously connect to different electrical terminals, eliminating the need for separate pick-and-place operations for each clip and thereby improving processing efficiency.
Solution Approach 2:
The clip structure is pre-configured with multiple contact portions and connection points before mounting. This preliminary configuration allows the entire clip assembly to be positioned and attached in a single operation, rather than requiring sequential mounting of individual clips, thus reducing processing time and complexity.
2Manufacturing precision
If separate clips are mounted to source and gate regions, then electrical connections can be established, but alignment inconsistencies occur between clips and die regions
Solution Approach 1:
By integrating multiple contact portions into a single clip structure with fixed relative positions, the patent ensures that all contact portions are positioned simultaneously relative to the die. This eliminates alignment inconsistencies that occur when separate clips are mounted independently, as the integrated structure maintains precise geometric relationships between all connection points.
Solution Approach 2:
The integrated clip structure incorporates different contact portions with specific local geometries optimized for their respective connection points. Each contact portion is precisely positioned and shaped for its specific function (source, gate, or other terminal connections), while maintaining consistent alignment across all portions through the unified structure.
3Ease of manufacture
If conventional packaging methods are used with separate clips, then connections can be made, but processing costs increase
Solution Approach 1:
The integrated clip structure reduces the number of components and assembly operations required. By combining multiple clips into one piece, the patent decreases material costs, assembly time, and labor requirements, thereby improving both manufacturing cost efficiency and processing speed simultaneously.
Solution Approach 2:
The pre-configured integrated clip structure eliminates the need for multiple separate mounting operations. The single-piece design allows for one-time attachment that accomplishes all necessary electrical connections, reducing processing time and associated labor costs while maintaining connection quality.
Data Source
AI summary
A method for making a premolded clip structure is disclosed. The method includes obtaining a first clip and a second clip, and forming a molding material around the first clip comprising a first surface and the second clip comprising a second surface. The first surface of the first clip structure and the second surface of the second clip structure are exposed through the molding material, and a premolded clip structure is then formed.