Lead Recess for Resin Package Bonding Strength
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Solution Overview
Problem
The existing surface-mounted semiconductor devices face issues with lead detachment from the resin package due to inadequate bonding strength, as leads are only held by bonding power between the upper surface and side surfaces of the resin package.
Innovation Solution
Incorporating a recess on the lower surface side of the lead, opened on its side surface, allows resin package material to infiltrate and securely hold the lead from both upper and lower sides, enhancing bonding strength and preventing detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the lead is held only by bonding power between the upper surface and side surfaces of the resin package, then the structure is simple, but the bonding strength is insufficient and the lead may come off
Solution Approach 1:
The invention transitions from two-dimensional bonding (upper surface and side surfaces only) to three-dimensional anchoring by introducing a recess that extends from the lower surface of the lead. This allows the resin package material to infiltrate and hold the lead from all directions (upper, side, and lower surfaces), effectively adding a dimensional aspect to the bonding structure without significantly complicating the overall device architecture.
2Reliability
If a recess is added to the lead structure, then the bonding strength is improved, but the manufacturing complexity increases
Solution Approach 1:
The recess is formed on the lead structure before the resin package molding process. This preliminary formation of the recess allows the lead to be prepared in advance with the appropriate geometry for resin infiltration, ensuring that when the resin is injected during molding, it can immediately fill the recess and create strong mechanical anchoring without requiring additional post-processing 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 design significantly improves the bonding strength between the lead and the resin package, ensuring the lead remains securely attached and preventing it from coming off, while maintaining sufficient contact area for wiring board connections.
Implementation Method 1
The material for the resin package infiltrates into the recess, whereby part of a peripheral edge portion of the lead is held by the resin package from both of the upper and lower sides thereof
Data Source
AI summary
A semiconductor device is disclosed. The semiconductor device has a semiconductor chip, an island having an upper surface to which the semiconductor chip is bonded, a lead disposed around the island, a bonding wire extended between the surface of the semiconductor chip and the upper surface of the lead, and a resin package sealing the semiconductor chip, the island, the lead, and the bonding wire, while the lower surface of the island and the lower surface of the lead are exposed on the rear surface of the resin package, and the lead is provided with a recess concaved from the lower surface side and opened on a side surface thereof.