Bond Wire Feed System with Clamp Alignment and Infrared Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The shrinking diameter of bond wires and the use of palladium coated copper wires, which are difficult to distinguish from the background of a bonding machine, lead to increased time consumption and potential damage to die electrodes due to insufficient bond wire length during manual wire threading and troubleshooting in wire bonding processes.
Innovation Solution
A wire feed system with a clamp mechanism and a current sensing circuit that aligns and straightens the bond wire, ensuring it protrudes correctly from the capillary welding tube, and a method to detect the presence of the wire using an infra-red sensor to prevent damage and ensure proper wire length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual wire threading is used during bond wire spool changing or troubleshooting, then operators can handle wire issues, but the process becomes more time consuming due to shrinking wire diameters
Solution Approach 1:
The system enables automatic wire feeding and threading through the capillary tube without operator intervention. The wire feed mechanism automatically advances the bond wire, and the sensing system detects when the wire protrudes sufficiently, eliminating the need for manual threading operations
Solution Approach 2:
The patent replaces manual mechanical threading operations with an automated system combining a wire feed mechanism, capillary tube positioning system, and optical sensing system that detects wire presence and length automatically
2Reliability
If palladium coated copper bond wires are used, then wire bonding performance is improved, but the wires become difficult to distinguish from the background of a bonding machine
Solution Approach 1:
The patent employs an optical sensing system that detects the presence and position of the bond wire through optical properties. The sensor system is designed to detect the wire regardless of its palladium coating by using appropriate wavelength detection that distinguishes the wire from the machine background
Solution Approach 2:
The patent introduces an infra-red sensor as an intermediary detection mechanism that can sense the wire presence through optical properties, acting as a mediator between the wire and the control system to enable automatic detection without direct visual observation
3Manufacturing precision
If insufficient bond wire length protrudes through the capillary welding tube, then wire feed issues occur, but damage to die electrodes may occur when wire bonding is attempted
Solution Approach 1:
The patent implements a feedback control system where sensors continuously monitor the wire protrusion length through the capillary tube. When the wire length is insufficient, the system provides feedback to stop the bonding operation, preventing damage to the die electrode. The sensor system detects wire presence and position, and the control system adjusts the wire feed accordingly
Solution Approach 2:
The patent performs preliminary detection of wire length and position before the bonding operation commences. The sensing system verifies that sufficient wire protrudes through the capillary tube before allowing the bonding process to start, preventing potential electrode damage from insufficient wire length
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 system reduces the time and effort required for wire threading and minimizes the risk of damage to die electrodes by ensuring the bond wire is correctly aligned and the appropriate length is maintained, enhancing the efficiency and reliability of the wire bonding process.
Implementation Method 1
a first sensor positioned to detect the presence of the wire when protruding from the wire outlet aperture
Data Source
AI summary
A bond wire feed system has a wire tensioning unit with a chamber that has a wire inlet aperture and a wire outlet aperture. The wire inlet and outlet apertures have centers that are aligned with a central axis of the chamber. A clamp is positioned to receive a bond wire provided from the wire outlet aperture. The clamp has at least two jaws movable relative to each other and arranged to grip the wire to align a central axis of the wire with the central axis of the chamber. The jaws are also movable along the central axis of the wire in order to pull the wire through the wire tensioning unit.