Sealed Lead Frame Layout for Void-Free Resin Filling
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Solution Overview
Problem
The existing semiconductor device manufacturing process using lead frames is prone to air entrapment during resin injection, leading to voids and incomplete sealing, which affects the integrity and functionality of the semiconductor device.
Innovation Solution
The electronic device design incorporates a conductive support member with a die pad and lead terminals, where the semiconductor elements and insulating elements are mounted, and a sealing resin is used to cover and isolate these components, ensuring complete resin filling and electrical insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If molten resin is injected at high speed during transfer molding, then resin filling efficiency is improved, but air entrapment occurs leading to voids and incomplete filling
Solution Approach 1:
The resin injection process is divided into multiple stages: initial low-speed injection to establish resin flow paths and displace air, followed by high-speed injection to fill the mold cavity efficiently, and finally low-speed injection to complete filling without air entrapment. This segmentation of the injection process resolves the contradiction between filling efficiency and filling completeness.
Solution Approach 2:
The injection speed is periodically adjusted during the transfer molding process. The mold controller varies the injection speed in different phases: slow speed at the beginning to prevent air entrapment, fast speed in the middle for efficient filling, and slow speed at the end to ensure complete filling without voids. This periodic action resolves the technical contradiction between productivity and manufacturing precision.
2Productivity
If resin injection speed is increased to improve productivity, then manufacturing time is reduced, but voids form near the injection site
Solution Approach 1:
The injection speed follows a periodic pattern with three distinct phases: initial low-speed injection to establish flow and prevent air entrapment, high-speed injection for efficient filling, and final low-speed injection to ensure complete filling. This periodic variation in injection speed maintains sealing integrity while improving overall manufacturing productivity.
Solution Approach 2:
The resin injection process maintains continuous flow throughout the mold cavity by carefully controlling injection speed variations. The continuous injection action, with speed adjustments rather than interruptions, ensures complete filling and prevents void formation while maintaining high productivity.
3Manufacturing precision
If air entrapment is prevented during resin injection, then sealing quality is improved, but injection process complexity increases
Solution Approach 1:
The mold controller monitors the resin injection process and adjusts injection speed based on feedback from pressure sensors and flow detection. This feedback mechanism enables automatic optimization of injection parameters to prevent air entrapment and ensure complete filling, improving sealing quality without requiring complex manual control procedures.
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 solution ensures complete resin filling and electrical insulation, preventing air entrapment and enhancing the reliability and performance of the semiconductor device.
Implementation Method 1
a sealing resin 5 is used to cover and isolate these components, ensuring complete resin filling and electrical insulation
Data Source
AI summary
An electronic device includes a conductive support, an electronic element on the conductive support, and a sealing resin covering the electronic element and the conductive support. The sealing resin has a first resin side surface facing in a first direction perpendicular to a thickness direction of the conductive support. The first resin side surface has a first gate mark. The conductive support includes a first region nearest to the first gate mark in the first direction. The first region is positioned inward of the first gate mark in a second direction perpendicular to the thickness direction and the first direction. The first gate mark has a first dimension in the thickness direction. The first gate mark and the first region are spaced in the first direction by a first distance. The ratio of the first distance to the first dimension is less than or equal to 500%.