Semiconductor Wire Loop with Inclined Riser for Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wire bonding methods result in wire loops with high neck portions that are unstable and prone to damage, and techniques to reduce neck height can damage the first bonding point or cause wire protrusion, leading to contact issues with adjacent bonding points.
Innovation Solution
A wire loop design featuring a riser part extending obliquely upward from the bonded ball at the first bonding point, with bends formed along the neck and major portions to reduce neck height and enhance stability without damaging the first bonding point, using a capillary to shape the wire during bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wire bonding methods are used to form wire loops with trapezoidal or triangular shapes, then the wire loop can connect bonding points, but the neck portion becomes high and unstable
Solution Approach 1:
The capillary performs a preliminary reverse operation before bonding to pre-form the wire into an inclined shape with a bend at the upper end. This preliminary shaping creates a lower neck portion height while maintaining structural stability, preventing the wire loop from being high and unstable
2Length of stationary object
If the capillary is moved in reverse operation to reduce neck portion height, then the wire loop profile is lowered, but the first bonding point may be damaged or wire may protrude
Solution Approach 1:
The capillary performs only a partial reverse operation (moving horizontally to a point in the direction opposite from the second bonding point) rather than a complete reversal. This partial action is sufficient to create the inclined wire shape and reduce neck height without excessive movement that would cause wire protrusion or damage to the first bonding point
3Shape
If multiple reverse operations are performed to form trapezoidal wire loop, then the wire loop has upper base portion, but the process complexity increases
Solution Approach 1:
The wire bonding process is segmented into distinct sequential operations: ball bonding, preliminary reverse operation with wire supply to form inclined portion and bend, optional second reverse operation for upper base portion, and final bonding. This segmentation allows flexible formation of different wire loop shapes (triangular or trapezoidal) by selectively performing operations, managing process complexity
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 solution creates a stable, low-profile wire loop with reduced neck height, preventing damage and protrusion, while maintaining strong shape retention and preventing bending or breakage, thus improving the reliability of the semiconductor device.
Implementation Method 1
the capillary 4 is horizontally moved to a point C in a direction opposite from the second bonding point Z... a bend 3a is formed in an upper end of the inclined portion of the wire 3 by a lower end of the capillary 4
Data Source
AI summary
A wire loop comprises a wire connecting a first bonding point and a second bonding point therethrough, wherein the wire includes a ball bonded to the first bonding point, a neck portion adjacent to the ball and a major portion extending from the neck portion to the second bonding point. The neck portion includes a riser part which extends, from the bonded ball, obliquely upward in a direction toward the second bonding point, and the riser part is formed by a top portion of the ball which has entered an opening of a capillary and been shaped at the time of ball bonding. The riser part is formed by inclining the top portion of the ball, which enters the opening of the capillary at the time of ball bonding, which inclining is done by moving the capillary obliquely upward toward the second bonding point.