Lead Frame Wiring Structure for Low-Inductance Insulation Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing semiconductor devices face challenges in maintaining insulation between lead frames due to damage from resin insulators, which can lead to reliability issues as the frequency of power converters increases, requiring effective solutions to reduce inductance and prevent moisture ingress.
Innovation Solution
The semiconductor device incorporates a wiring unit with a specific configuration of plate-shaped lead frames and a wiring holding portion that fills gaps between the lead frames, ensuring insulation and reducing stress concentrations, using a thermoplastic resin for the wiring holding portion and a sealing member to prevent damage and maintain insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If lead frames are disposed adjacently to reduce inductance, then inductance is reduced, but the resin insulator may crack or peel due to stress concentration
Solution Approach 1:
A resin-filled groove is introduced as an intermediary structure between adjacent lead frames. This groove receives and holds resin material that acts as a stress-absorbing intermediary, preventing direct stress transmission between lead frames while maintaining electrical insulation. The resin in the groove fills and absorbs stress concentrations that would otherwise cause cracking or peeling of the main insulator.
Solution Approach 2:
The insulation system uses a composite structure combining rigid lead frames with flexible resin material. The resin-filled groove creates a composite insulation system where the resin material complements the rigid lead frame structure, providing both mechanical stress absorption and electrical insulation properties that neither component could achieve alone.
2Power
If high voltage is applied between lead frames, then power conversion capability is improved, but insulation requirements become more stringent
Solution Approach 1:
The resin-filled groove serves as an additional intermediary insulation layer between high-voltage lead frames. This extra resin layer provides enhanced electrical insulation and stress distribution, enabling the device to handle higher voltages while maintaining insulation stability through the stress-absorbing properties of the resin.
3Speed
If lead frames are disposed adjacently to reduce inductance, then inductance is reduced, but moisture may enter through exposed ends
Solution Approach 1:
The resin-filled groove acts as a flexible sealing structure that prevents moisture ingress. The resin material forms a continuous protective film or shell around the exposed ends of adjacent lead frames, creating a moisture barrier that seals the structure while allowing for thermal expansion and contraction.
Data Source
AI summary
A first wiring member bends at a first bent portion in the shape of the letter “L” in a side view and includes a first horizontal portion parallel to the principal surface of a semiconductor chip and a first vertical portion perpendicular to the first horizontal portion. A second wiring member bends at a second bent portion in a direction opposite to the first wiring member in the shape of the letter “L” in the side view and includes a second horizontal portion flush with the first horizontal portion and a second vertical portion a determined distance distant from the first vertical portion and parallel to the first vertical portion. A wiring holding portion fills a gap between the first and second vertical portions and a gap between the first and second bent portions. Therefore, stress applied to the vicinity of the first or second bent portion is relaxed.