Semiconductor Ball Formation Gas Flow Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of initial balls using easily oxidizable conductive wires in semiconductor device manufacturing often results in shape defects due to oxidation, leading to damage when pressed onto pads, as the antioxidant gas concentration may be insufficient and flow rates can be unstable, causing variations in diameter and eccentricity.
Innovation Solution
A ball formation unit with a gas inlet for introducing antioxidant gas and a gas outlet positioned differently from the gas inlet, stabilizing the gas flow and preventing turbulent collisions, ensuring a consistent and spherical initial ball formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If antioxidant gas is introduced during initial ball formation, then oxidation of the conductive wire is suppressed, but the gas flow rate becomes unstable and turbulent collisions occur causing shape defects
Solution Approach 1:
The gas outlet is divided into multiple outlets arranged in a ring shape around the capillary, rather than using a single gas outlet. This segmentation distributes the gas flow uniformly around the initial ball formation area, preventing turbulent collisions and ensuring stable antioxidant gas coverage without causing shape defects
Solution Approach 2:
The ring-shaped gas outlets act as an intermediary structure between the gas source and the initial ball formation area. This intermediary arrangement ensures uniform gas distribution and prevents direct turbulent flow onto the melting wire, thereby maintaining both oxidation protection and shape uniformity
2Object-affected harmful factors
If gas flow rate is increased to ensure antioxidant atmosphere, then oxidation is prevented, but diameter variations occur due to unstable flow
Solution Approach 1:
The gas outlet is segmented into multiple outlets arranged in a ring, which distributes the total gas flow rate across multiple smaller openings. This segmentation stabilizes the local gas flow velocity at each outlet, preventing turbulence and diameter variations while maintaining sufficient antioxidant atmosphere coverage
Solution Approach 2:
The invention changes the geometric parameters of the gas outlet system by arranging multiple outlets in a ring shape at a specific distance from the capillary tip. This parameter change optimizes the gas flow distribution pattern, ensuring stable flow rates that prevent both oxidation and diameter variations
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 shape defects in initial balls, minimizing damage to pads during bonding and enhancing the reliability of semiconductor devices by maintaining a stable gas flow and concentricity of the initial balls.
Implementation Method 1
a gas inlet portion for introducing an antioxidant gas into the ball formation portion
Implementation Method 2
electricity is discharged between a torch electrode and a wire protruding from the tip portion of the capillary. This discharge generates heat and due to the heat thus generated, the tip portion of the wire is melted
Implementation Method 3
The melted wire becomes spherical due to surface tension and thus, a spherical initial ball can be formed
Implementation Method 4
the gas outlet portion is provided in a direction different from the direction of introducing the antioxidant gas into the ball formation portion... stabilizing the gas flow and preventing turbulent collisions
Data Source
AI summary
Provided is a technology of suppressing, in forming an initial ball by using an easily oxidizable conductive wire and pressing the initial ball onto a pad to form a press-bonded ball, an initial ball from having a shape defect, thereby reducing damage to the pad. To achieve this, a ball formation unit is equipped with a gas outlet portion for discharging an antioxidant gas and a discharging path through this gas outlet portion is placed in a direction different from a direction of introducing the antioxidant gas into a ball formation portion. Such a structure widens a region for discharging the antioxidant gas, making it possible to prevent a gas flow supplied from the side of one side surface of the ball formation portion from being reflected by the other side surface facing with the one side surface and thereby forming a turbulent flow.