Wire Bonding Oxidation Prevention Gas Nozzle
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Solution Overview
Problem
Existing wire bonding devices using copper wires face challenges in preventing oxidation of free air balls (FABs) due to turbulent flow of oxidation prevention gases and external air ingress, which limits the formation of large diameter FABs and affects bonding quality.
Innovation Solution
A wire bonding method and device that supplies oxidation prevention gas both internally through a capillary and externally via a gas supply nozzle, covering the inlet of the insertion portion to maintain a stable gas atmosphere and prevent oxidation, allowing for the formation of large diameter FABs by generating spark discharge until the FAB protrudes outside the insertion portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxidation prevention gas is supplied through the gas confining tube to prevent oxidation, then oxidation of the FAB is suppressed, but external air ingress causes turbulent flow that limits the formation of large diameter FABs
Solution Approach 1:
The gas supply system is divided into two independent parts: an internal gas supply through the capillary and an external gas supply through the gas supply nozzle. This segmentation allows each part to perform its specific function - the internal supply creates the oxidation prevention atmosphere inside the insertion portion, while the external supply covers the inlet to prevent external air ingress, together resolving the contradiction between oxidation prevention and FAB formation capability
Solution Approach 2:
The gas supply nozzle acts as an intermediary component that bridges the external environment and the insertion portion inlet. It supplies oxidation prevention gas to cover the inlet area, preventing external air from entering while allowing the capillary to protrude outside for large diameter FAB formation, thus mediating between oxidation prevention requirements and FAB formation needs
2Reliability
If the capillary is inserted into the gas confining tube to maintain gas atmosphere, then oxidation prevention is achieved, but the capillary must be retracted to form large diameter FABs which causes oxidation
Solution Approach 1:
The gas supply nozzle performs preliminary action by covering the insertion portion inlet with oxidation prevention gas before the capillary needs to protrude outside. This preliminary gas coverage ensures that when the capillary is retracted for large diameter FAB formation, the inlet remains protected from external air, preventing oxidation during the capillary retraction and FAB formation process
Solution Approach 2:
The solution moves from a one-dimensional internal gas supply to a two-dimensional gas coverage system by adding the external gas supply nozzle. This allows gas to be supplied both inside the insertion portion through the capillary and outside covering the inlet through the nozzle, creating a comprehensive gas atmosphere that protects against oxidation while enabling capillary retraction for large diameter FAB formation
3Volume of moving object
If the capillary protrudes outside the gas confining tube to form large diameter FABs, then FAB size is increased, but external air contact causes oxidation
Solution Approach 1:
The gas supply nozzle creates an inert atmosphere by supplying oxidation prevention gas to cover the insertion portion inlet. This inert gas environment surrounds the capillary and FAB formation area, preventing external air from contacting the wire and FAB even when the capillary protrudes outside, thus enabling large diameter FAB formation without oxidation
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 effectively suppresses oxidation and stabilizes the formation of large diameter FABs, enabling reliable bonding even for IC chips with larger wire lengths by ensuring a consistent oxidation prevention gas environment.
Implementation Method 1
generate spark discharge between the wire and a spark rod arranged inside the insertion portion to form a free air ball at the leading end of the wire
Data Source
AI summary
To provide a wire bonding method and a wire bonding device capable of stably forming a free air ball having a large ball diameter while suppressing oxidation of the free air ball, in addition to supply of an oxidation prevention gas from gas supply means (10) into an insertion portion (32), an oxidation prevention gas is supplied from a gas supply nozzle (40), which is arranged outside the insertion portion (32), so as to cover an inlet of the insertion portion (32). Under a state in which a leading end of a wire (74) is positioned inside the insertion portion (32), and in which a leading end of a capillary (3) is positioned outside the insertion portion (32), spark discharge is generated. With this, a free air ball (75) having a large ball diameter can be formed while suppressing oxidation of the free air ball (75) and stabilizing the free air ball (75).