Arched Conductive Strip for Stress-Resistant Die Interconnects
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Solution Overview
Problem
Existing electrical connections for semiconductor dice, particularly in power devices, suffer from reliability issues due to thermal and mechanical stress, leading to degradation and detachment of bonding materials like soldering and sintering, which are costly and inadequate for applications like the automotive sector.
Innovation Solution
A conductive elastic connecting strip with an arched shape, featuring alternating projecting and recessed areas, is used to form an electrical connection between semiconductor dice and a support, utilizing ultrasonic welding or sintering to ensure durable and reliable contact without intermediate bonding materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soldering or sintering bonding materials are used to connect semiconductor dice to support, then electrical connection is achieved, but reliability deteriorates due to degradation and detachment under thermal and mechanical stress
Solution Approach 1:
The invention removes intermediate bonding materials (soldering or sintering materials) from the connection structure. The connecting strip directly contacts the semiconductor die and support without any bonding material in between, eliminating the source of degradation and detachment under thermal and mechanical stress.
Solution Approach 2:
The connecting strip is made of elastic conductive material that combines electrical conductivity with mechanical elasticity. This composite material property allows the strip to maintain electrical connection while adapting to thermal expansion and mechanical stresses through elastic deformation rather than rigid bonding.
2Reliability
If rigid connection structures are used to ensure stable electrical contact, then electrical connection is maintained, but susceptibility to thermal and mechanical stress increases
Solution Approach 1:
The connecting strip transitions from a rigid static connection to a dynamic elastic connection. The strip can deform elastically in response to thermal expansion and mechanical stresses, maintaining stable electrical contact while absorbing stress variations that would damage rigid connections.
Solution Approach 2:
The invention changes the mechanical parameter of the connection from rigid to elastic. The elastic property allows the connecting strip to change its shape and contact pressure in response to environmental conditions, maintaining reliable electrical connection under varying thermal and mechanical conditions.
3Reliability
If intermediate bonding materials are used to form electrical connections, then connection is achieved, but cost increases and reliability decreases
Solution Approach 1:
The invention extracts and eliminates intermediate bonding materials from the connection process. This removal simplifies the manufacturing process, reduces material costs, and eliminates the reliability issues associated with bonding material degradation under thermal and mechanical stress.
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 connecting strip provides high endurance and reliability, resisting mechanical stresses and thermal variations, while minimizing parasitic effects and reducing costs, ensuring stable electrical contact through elastic pressure and uniform thermal expansion coefficients.
Implementation Method 1
a connecting strip (50) of conductive elastic material... elastically presses against the at least one die (72, 73)... The elastic body (61) may have a thickness between 300 μm and 1 mm... and the contact layer (62)... with a thickness smaller than the thickness of the elastic body (61)
Data Source
AI summary
A connecting strip of conductive elastic material having an arched shape having a concave side and a convex side. The connecting strip is fixed at the ends to a support carrying a die with the convex side facing the support. During bonding, the connecting strip undergoes elastic deformation and presses against the die, thus electrically connecting the at least one die to the support.