Recessed Semiconductor Connection Members for Reliable Stacking
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Solution Overview
Problem
Conventional semiconductor device manufacturing methods for multi-chip stack structures face challenges such as short-circuiting defects, cracking, and inadequate joining due to protruding connection members and ultrasonic vibration-induced deformations, which affect the electrical and mechanical connections between semiconductor chips and solid-state devices.
Innovation Solution
The method involves preparing semiconductor chips with recessed rear surface connection members that do not protrude, allowing even force distribution and preventing deformation, combined with the use of ultrasonic vibrations to ensure effective joining without attenuation, and the incorporation of materials with different deformability for stress absorption and improved structural strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If connection members protrude from the semiconductor chip surface to enable electrical connection, then electrical connectivity is achieved, but short-circuiting defects occur due to deformation during joining
Solution Approach 1:
Instead of making connection members protrude from the chip surface (conventional approach), the patent inverts the design by recessing the connection members into the chip substrate. This inversion prevents the connection members from deforming during the joining process, as they are protected within the recessed structure, thereby eliminating short-circuiting defects while maintaining electrical connectivity.
Solution Approach 2:
The patent applies beforehand cushioning by creating recessed structures in the chip substrate that accommodate the connection members. These recesses act as protective cushions during the joining process, preventing direct contact and deformation of the connection members with external tools or adjacent components, thus preventing short-circuits before they can occur.
2Manufacturing precision
If ultrasonic vibration is applied during joining to ensure effective connection, then joining quality improves, but connection member deformation occurs leading to short-circuits
Solution Approach 1:
The recessed structure serves as a pre-established protective cushion that shields the connection members from the harmful effects of ultrasonic vibration during joining. The connection members remain embedded within the recesses, preventing them from vibrating excessively or deforming, while still allowing effective energy transfer for high-quality joining.
3Strength
If force is applied during joining to ensure mechanical attachment, then structural strength improves, but non-uniform force distribution causes cracking
Solution Approach 1:
The recessed structures distribute the applied joining force uniformly across the chip substrate. By accommodating the connection members within these pre-formed recesses, the force is distributed along the recess walls and base rather than concentrating at specific points, preventing stress concentration and subsequent cracking while maintaining strong mechanical attachment.
4Stability of the object's composition
If connection members are made deformable to absorb stress, then stress absorption improves, but short-circuiting defects occur due to lateral spreading
Solution Approach 1:
Instead of allowing connection members to deform freely (conventional approach), the patent inverts the approach by constraining deformable connection members within recessed structures. This allows the connection members to absorb stress through controlled elastic deformation within the recesses, while the recess walls prevent lateral spreading that would cause short-circuits between adjacent connection members.
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 approach reduces the likelihood of short-circuiting defects and cracking, enhances the joining quality between semiconductor chips and solid-state devices, and maintains structural integrity by ensuring even force distribution and effective stress absorption.
Implementation Method 1
the use of ultrasonic vibrations to ensure effective joining without attenuation
Data Source
AI summary
A manufacturing method for a semiconductor device includes: the step of preparing a semiconductor chip which is provided with a functional element formed on a front surface side of a semiconductor substrate, a feedthrough electrode which is placed within a through hole that penetrates the semiconductor substrate, a front surface side connection member which protrudes from the front surface, and a rear surface side connection member which has a joining surface within a recess that is formed in a rear surface; the step of preparing a solid-state device where a solid-state device side connection member for connection to the front surface side connection member is formed on one surface; and the joining step of making the front surface of the semiconductor chip face the first surface of the solid-state device by holding the rear surface of the semiconductor chip, and of joining the front surface side connection member to the solid-state device side connection member.