Two-Stage Die Bonding Head for Warpage Gap Elimination
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Solution Overview
Problem
The increasing complexity of integrated circuit packages, which include multiple device dies, poses challenges in bonding due to warpage issues that lead to gaps and reduced reliability and yield.
Innovation Solution
A device bonding apparatus with two-stage pre-anneal bonding process using a first bond head with a rigid body and vacuum channels for initial attachment, followed by a second bond head with an elastic head to apply differential forces, reducing or eliminating gaps caused by warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-stage bonding process is used, then the process is simple and fast, but warpage causes gaps and reduces bonding reliability
Solution Approach 1:
The bonding process is divided into two distinct stages: a first bonding stage and a second bonding stage. The first bond head performs initial bonding with a first bonding force, and the second bond head performs subsequent bonding with a second bonding force. This segmentation allows each stage to address specific aspects of the bonding challenge, improving overall reliability while managing complexity through structured process division.
Solution Approach 2:
The first bond head performs preliminary bonding action before the second bond head acts. This preliminary action establishes an initial bond that prepares the workpiece for the subsequent bonding stage, addressing warpage issues progressively rather than attempting to solve all problems in a single step.
2Reliability
If a first bond head performs first bonding, then initial attachment is achieved, but warpage-induced gaps remain
Solution Approach 1:
The bonding process continues from the first bond head to the second bond head without interruption. The second bond head performs additional bonding action on the workpiece after the first bond head has completed its bonding, ensuring continuous application of bonding forces to eliminate gaps caused by warpage and achieve complete contact.
Solution Approach 2:
The second bond head applies bonding force to specific regions of the workpiece that require additional bonding pressure to eliminate gaps. This localized quality approach allows different regions of the workpiece to receive appropriate bonding forces based on their specific needs, ensuring complete gap elimination while maintaining overall bonding reliability.
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
Improves the process yield and reliability of bonding by effectively addressing warpage-related issues, ensuring consistent and secure attachment of semiconductor dies to wafers.
Implementation Method 1
a first bond head including a first rigid body and a vacuum channel in the first rigid body for providing an attaching force for carrying the die to the wafer
Implementation Method 2
a second bond head including a second rigid body and an elastic head disposed over the second rigid body for pressing the die, the elastic head having a center portion and an edge portion surrounding the center portion
Data Source
AI summary
In an embodiment, a device bonding apparatus is provided. The device bonding apparatus includes a first process station configured to receive a wafer; a first bond head configured to carry a die to the wafer, wherein the first bonding head includes a first rigid body and a vacuum channel in the first rigid body for providing an attaching force for carrying the die to the wafer; and a second bond head configured to press the die against the wafer, the second bond head including a second rigid body and an elastic head disposed over the second rigid body for pressing the die, the elastic head having a center portion and an edge portion surrounding the center portion, the center portion of the elastic head having a first thickness, the edge portion of the elastic head having a second thickness, the second thickness being greater than the second thickness.