Deformed Suspension Lead Frame for Wire Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lead frames are inflexible and cannot accommodate various semiconductor chip designs, leading to potential short circuits during wire bonding due to narrow wire intervals, especially when chips are mounted in different packages or under product constraints.
Innovation Solution
A lead frame design where at least one suspension lead is deformed to create a wider space between inner leads, allowing for flexible wire bonding without short circuits, by using a shape with a connection section and descent section that absorbs stress and displacement, enabling the use of a common lead frame for multiple chip designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the chip is mounted on an existing lead frame with fixed structure, then the lead frame structure is simple and manufacturing is easy, but the wire interval becomes very narrow causing adjacent wires to contact and form short circuits
Solution Approach 1:
The lead frame incorporates a movable suspension lead that can be deformed from its initial position to create additional space. This dynamic adjustment allows the wire interval to be increased without changing the overall lead frame structure, resolving the contradiction between manufacturing simplicity and wire bonding reliability.
Solution Approach 2:
The invention changes the positional parameter of the suspension lead by deforming it from its original location. This parameter change increases the wire interval and prevents short circuits while maintaining the same lead frame base structure, thus preserving manufacturing simplicity.
2Reliability
If the lead frame structure is deformed to increase wire interval, then wire bonding reliability improves, but the lead frame structure becomes complex
Solution Approach 1:
The lead frame is segmented into a fixed base structure and a movable suspension lead component. Only the suspension lead is deformed to create space, while the rest of the lead frame remains simple and unchanged, thus improving wire bonding reliability without significantly increasing overall structural complexity.
3Reliability
If a new lead frame is designed for each chip specification, then wire bonding reliability is ensured, but manufacturing cost increases and design flexibility decreases
Solution Approach 1:
The lead frame is designed with a universal base structure that can accommodate different chip specifications. The suspension lead can be deformed as needed to ensure proper wire bonding for various chip types, making the same lead frame design versatile for multiple applications without requiring new designs for each chip specification.
4Reliability
If the suspension lead is deformed to create space, then wire interval increases preventing short circuits, but the suspension lead structure becomes more complex
Solution Approach 1:
Only the local region of the suspension lead that requires space creation is deformed, while the rest of the suspension lead maintains its simple original structure. This localized deformation ensures wire bonding reliability without unnecessarily complicating the entire suspension lead structure.
Data Source
AI summary
A semiconductor device includes: a semiconductor chip, and a lead frame. The semiconductor chip is mounted over a die pad. Four suspension leads are connected with the die pad and at least one of them is provided between first and second lead groups and is deformed to protrude toward the first lead group. At least one of the leads of the second lead group which is nearer to the deformed suspension lead is deformed to be apart from remaining leads of the second lead group.