Semiconductor Bonding With Dual-Wavelength Laser Welded Lead Member
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Solution Overview
Problem
The existing semiconductor devices face reliability issues due to damage caused by ultrasonic bonding, which applies pressure and vibrations, affecting the electrical connection between the strap and the source electrode of the semiconductor element.
Innovation Solution
A semiconductor device and bonding method that utilize laser welding with two laser beams of different wavelengths to connect an electrically conductive member to the semiconductor element, avoiding the use of ultrasonic bonding and ensuring a reliable electrical connection without damaging the semiconductor element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultrasonic bonding is used to join the strap to the source electrode, then electrical connection is ensured, but the semiconductor element may be damaged by pressure and vibration
Solution Approach 1:
The patent replaces the mechanical ultrasonic bonding system with a laser welding system. Instead of using mechanical pressure and ultrasonic vibrations to join the strap to the source electrode, the invention uses laser energy to melt and fuse the materials together, eliminating the harmful mechanical stresses while achieving reliable electrical connection.
Solution Approach 2:
The patent changes the bonding method from mechanical (ultrasonic) to thermal (laser). By changing the fundamental parameter of the bonding process from mechanical vibration to laser heating, the invention achieves the same joining function without the harmful side effects of pressure and vibration on the semiconductor element.
2Object-affected harmful factors
If laser welding with two laser beams of different wavelengths is used, then damage from pressure and vibration is avoided, but the device complexity increases
Solution Approach 1:
The patent divides the laser welding process into two separate laser beams with different wavelengths. The first laser beam (e.g., infrared) penetrates deeper to melt the substrate, while the second laser beam (e.g., green or blue) acts on the surface to control the welding quality. This segmentation allows each laser to perform its specific function optimally without interfering with the other.
Solution Approach 2:
The patent applies different wavelengths of laser beams to different depths and regions of the bonding interface. The first laser beam targets the deeper substrate region for melting, while the second laser beam targets the surface region for controlled fusion. This local differentiation of laser parameters optimizes the welding process for each specific zone.
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 method improves the reliability of the semiconductor device by preventing damage from pressure and vibrations, ensuring a durable and efficient electrical connection between the conductive members and the semiconductor element.
Implementation Method 1
bonding the connecting member to the electrically conductive member by laser welding
Implementation Method 2
bonding the connecting member to the electrically conductive member by laser welding
Data Source
AI summary
Semiconductor device A1 of the disclosure includes: semiconductor element 11 having element obverse surface 11a and element reverse surface 11b spaced apart from each other in z direction (first direction) with first region 111 formed on the element obverse surface 11a; metal plate 31 (electrode member) disposed on the element obverse surface 11a and electrically connected to the first region 111; electrically conductive substrate 22A (first conductive member) disposed to face the element reverse surface 11b and bonded to the semiconductor element 11; electrically conductive substrate 22B (second conductive member) spaced apart from the conductive substrate 22A (first conductive member); and lead member 5 (connecting member) electrically connecting the metal plate 31 (electrode member) and the conductive substrate 22B (second conductive member). The lead member 5 (connecting member) is bonded to the metal plate 31 (electrode member) by laser welding. The semiconductor device of this configuration provides improved reliability.