Wire Bonding Tool Cut Portion for Tail Length Control
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Solution Overview
Problem
In semiconductor device manufacturing, the tip of the wire tail after bonding can come into contact with adjacent electrodes or passivation films, causing damage or defects, especially at the first bonding point in wedge bonding systems, limiting design freedom and efficiency.
Innovation Solution
A semiconductor device manufacturing method involving a wire loop connection between bonding points, where the bonding tool forms a cut portion near the second bonding point, allowing for easy adjustment and cutting of the wire tail, ensuring it remains within the electrode region for reliable bonding and accommodating narrow pitches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wedge bonding is used to connect wires between bonding points, then bonding efficiency is improved, but the wire tail may contact adjacent electrodes or passivation films causing damage or defects
Solution Approach 1:
The patent forms a ball at the tip of the wire tail before bonding operations. This preliminary action ensures that when the wire tail is used for subsequent bonding, the ball portion makes contact with the bonding electrode first, preventing the wire tail from contacting and damaging adjacent electrodes or passivation films. The ball formation occurs in advance, allowing the wire tail to be safely reused for multiple bonding operations.
2Ease of operation
If the bonding tool is moved with each wire bonding to arrange wire tail shape, then wire tail placement is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs a mold member that automatically shapes the wire tail during the bonding process without requiring additional bonding tool movements. The mold member is positioned in the bonding region and passively forms the wire tail into the desired shape as the bonding tool operates, enabling the wire tail to assume the correct configuration for subsequent bonding operations without manual intervention or complex tool path planning.
3Reliability
If reverse bonding is used to solve wire tail contact issues, then damage risk is reduced, but design freedom is limited
Solution Approach 1:
The patent forms a ball at the wire tail tip in advance, which allows bonding to proceed in the conventional forward direction (from first bonding point to second bonding point) while still preventing wire tail contact issues. This preliminary ball formation enables the use of standard bonding sequences and maintains design freedom, unlike reverse bonding which constrains the bonding order. The ball acts as a protective element that allows flexible bonding path planning.
Solution Approach 2:
The ball formed at the wire tail tip serves as an intermediary element between the wire tail and the bonding electrode. Instead of directly bonding the wire tail to the electrode, the ball makes contact first, mediating the bonding process and preventing the wire tail from contacting adjacent structures. This intermediary approach maintains conventional bonding sequences while solving the contact problem.
Data Source
AI summary
A semiconductor device manufacturing method includes: raising and moving a bonding tool, while paying out a wire, in a direction from a second toward a first bonding point to form in the wire a cut portion bent in a vicinity of the second bonding point; lowering and moving a tip of the bonding tool to the cut portion; lowering the bonding tool vertically to thin the cut portion; raising the bonding tool while paying out the wire; and moving the bonding tool in a direction away from the first and second bonding points and along a wire direction connecting the first and second bonding points and then cutting the wire at the cut portion to form a wire tail. This allows the length of the wire tail to be adjusted easily and efficiently to be constant.