Semiconductor Lead Bonding Structure for Consistent Wire Height
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Solution Overview
Problem
Inconsistent height of the conductive member from the conductive obverse surface due to non-uniform conductive bonding materials in semiconductor devices, leading to potential issues in the manufacturing process and heat dissipation.
Innovation Solution
The conductive member is bonded directly to the pad portion of the lead without intervening bonding materials, ensuring consistent height and using ultrasonic bonding or laser welding for secure attachment, and optionally incorporating a heat-conducting member for enhanced heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If two layers of conductive bonding material are used to bond the semiconductor element and conductive member, then the bonding strength is improved, but the height consistency of the conductive member deteriorates
Solution Approach 1:
The invention removes one layer of conductive bonding material from the bonding structure. Specifically, the conductive member is bonded directly to the pad portion of the lead without intervening bonding materials, eliminating the source of height variation while maintaining bonding strength through direct contact and alternative bonding methods.
Solution Approach 2:
The invention introduces ultrasonic bonding or laser welding as an intermediary bonding mechanism. Instead of relying solely on conductive bonding materials, these energy-based bonding methods enable direct bonding between the conductive member and pad portion, achieving both strong adhesion and consistent height positioning.
2Strength
If conductive bonding material is used to bond the conductive member to the pad portion, then the bonding strength is improved, but the height consistency of the conductive member deteriorates
Solution Approach 1:
The invention removes the conductive bonding material from the interface between the conductive member and pad portion. This extraction eliminates the thickness variation inherent in bonding materials, ensuring that the top surface of the conductive member aligns consistently with the obverse surface of the lead.
Solution Approach 2:
The invention replaces the mechanical bonding system (conductive bonding material) with energy-based bonding systems (ultrasonic vibration or laser welding). These systems create direct metallurgical bonds without requiring intermediate materials, thereby eliminating height inconsistency while maintaining bonding strength.
3Manufacturing precision
If the conductive member is bonded directly to the lead without bonding materials, then the height consistency is improved, but the bonding strength may deteriorate
Solution Approach 1:
The invention replaces mechanical bonding with ultrasonic bonding or laser welding. Ultrasonic bonding uses high-frequency mechanical vibrations to create diffusion bonds at the interface, while laser welding uses concentrated laser energy to melt and fuse the materials. Both methods achieve bonding strengths comparable to or exceeding traditional soldering without requiring intermediate materials.
Solution Approach 2:
The invention changes the bonding parameters from material-based (thickness, composition of bonding material) to process-based (ultrasonic power, laser energy, bonding pressure, temperature). These parameter changes enable precise control over the bonding process, ensuring both strong adhesion and consistent height positioning.
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
Ensures consistent height of the conductive member, prevents rotation during reflow, and allows efficient heat dissipation from both sides, improving manufacturing precision and thermal management.
Implementation Method 1
using ultrasonic bonding or laser welding for secure attachment
Implementation Method 2
using ultrasonic bonding or laser welding for secure attachment
Data Source
AI summary
A semiconductor device includes a first lead, a semiconductor element, a second lead, a conductive member, and a sealing resin. The first lead includes a die pad having a die-pad obverse surface facing a first side in a thickness direction. The semiconductor element has an element obverse surface facing the first side in the thickness direction and includes a first electrode disposed on the element obverse surface. The semiconductor element is mounted on the die-pad obverse surface. The second lead has a second obverse surface facing the first side in the thickness direction and is spaced apart from the first lead in a first direction perpendicular to the thickness direction. The conductive member is electrically bonded to the first electrode and the second obverse surface. The sealing resin covers the semiconductor element. The conductive member is in direct contact with the second lead.