Semiconductor Device Thermosetting Resin Lead Securing
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Solution Overview
Problem
In resin-sealed semiconductor devices, the thermoplastic resin used for securing leads to a die pad can soften when heated, causing the leads to drop out of their sealing part, which is a reliability issue during assembly or connection to other components.
Innovation Solution
The semiconductor device employs a thermosetting resin to secure the ends of the leads to the die pad, which is then sealed with a thermoplastic resin, ensuring the leads remain secured even when heated, and the thermosetting resin part can overlap or be embedded in the die pad for enhanced adhesion and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thermoplastic resin is used to secure leads to die pad, then ease of manufacture is improved, but reliability deteriorates when heated
Solution Approach 1:
The patent divides the resin sealing function into two separate components: a thermoplastic resin for sealing and a thermosetting resin for securing leads. This segmentation allows each resin type to perform its specialized function optimally - the thermoplastic resin provides easy manufacturing through injection molding while the thermosetting resin provides heat-resistant lead securing, thus resolving the contradiction between ease of manufacture and reliability under heat.
Solution Approach 2:
The patent uses a composite structure combining thermoplastic resin and thermosetting resin in a single sealing assembly. The thermoplastic resin layer provides sealing and the thermosetting resin layer provides heat-resistant lead fixation. This composite material approach allows the device to benefit from both the manufacturing ease of thermoplastic resin and the thermal stability of thermosetting resin, simultaneously improving ease of manufacture and reliability.
2Ease of manufacture
If thermoplastic resin is used for sealing, then ease of manufacture is improved, but leads may drop out when heated
Solution Approach 1:
The patent segments the resin functions into two distinct layers: thermoplastic resin for sealing and thermosetting resin for lead securing. This segmentation ensures that the thermosetting resin maintains stable composition and adhesion under heat, preventing lead dropout, while the thermoplastic resin maintains ease of manufacture through its molding properties.
Solution Approach 2:
The composite resin structure combines thermoplastic and thermosetting resins, where the thermosetting resin component provides thermal stability and prevents lead dropout when heated, while the thermoplastic resin component maintains manufacturing ease. This composite approach simultaneously achieves ease of manufacture and compositional stability under heat.
3Reliability
If thermosetting resin is used to secure leads, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the lead-securing function and sealing function into a single integrated resin assembly consisting of thermoplastic resin and thermosetting resin layers. This merging allows the thermosetting resin to provide reliable lead securing while the thermoplastic resin provides sealing, achieving high reliability without requiring separate components for each function, thus minimizing device complexity.
Solution Approach 2:
The composite resin structure combines thermoplastic and thermosetting resins in a single integrated assembly that performs both lead securing and sealing functions. This composite approach achieves reliable lead securing under heat while maintaining manufacturing simplicity through a unified structure, thereby improving reliability without significantly increasing device complexity.
4Strength
If thermosetting resin part overlaps die pad, then adhesion is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent incorporates the thermosetting resin part into the die pad structure before the final sealing process. By preliminarily forming the die pad with integrated thermosetting resin regions, the adhesion strength is enhanced while the positioning and alignment are established in advance, reducing the precision requirements during subsequent manufacturing steps.
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 configuration prevents the leads from dropping out of the resin sealing even under heat, providing stable electrical connections and improved reliability, especially for high-heat semiconductor devices like MOS-FETs using SiC or GaN.
Implementation Method 1
a thermosetting resin part for securing the end part of the first lead to the die pad
Implementation Method 2
a thermoplastic resin part for sealing the semiconductor chip, the die pad, and the thermosetting resin part
Data Source
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AI summary
A semiconductor device (10) in accordance with an embodiment comprises a semiconductor chip (14); a die pad (12) having a chip mount surface (12a) for mounting the semiconductor chip; first leads (18, 20) electrically connected to the semiconductor chip; a thermosetting resin part (22) for securing end parts (18A, 20A) of the first leads to the die pad; and a thermoplastic resin part for sealing the semiconductor chip, the die pad, and the thermosetting resin part.