Wire Payout Calibration via Optical Loop Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for measuring wire payout in wire bonding machines are inaccurate and time-consuming, leading to inconsistent wire loops due to uncontrolled process variables such as tension and friction, which affect the shape of the wire loop.
Innovation Solution
The method involves determining wire payout lengths during predetermined looping motions using a bond head with a wire clamp and bonding tool, allowing for adjustments to process variables to achieve consistent wire payout, either within the same or different wire bonding systems, by measuring the distance the wire clamp is raised above a predetermined point until the wire tears, and calculating the payout length as the difference between these distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If offline manual measurements are used to calculate wire payout, then measurement can be performed, but measurement precision and time efficiency deteriorate
Solution Approach 1:
The patent replaces manual mechanical measurement methods with an automated optical measurement system. The system uses a camera to capture images of the wire loop and automatically calculates wire payout through image processing and coordinate transformation algorithms, eliminating the need for manual measurement while improving both accuracy and efficiency.
Solution Approach 2:
The patent introduces an intermediary measurement system consisting of a camera, image processing unit, and calculation algorithm. This intermediary system acts as a mediator between the wire bonding process and the measurement outcome, enabling automated, precise, and rapid wire payout measurement without direct human intervention.
2Productivity
If process variables such as tension and friction are not controlled, then wire bonding operations can proceed, but wire loop consistency deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where wire payout is measured for each wire loop, and the measured values are used to adjust process variables for subsequent loops. The system calculates average payout, standard deviation, and trends, then uses this information to optimize tension and other parameters, ensuring consistent wire loop shapes while maintaining continuous production.
Data Source
AI summary
A method of calibrating a wire payout related to predetermined looping motions used during formation of a wire loop is provided. The method includes the steps of: (a) determining a first wire payout length related to predetermined wire looping motions used in the formation of a first of the wire loop, the predetermined looping motions being performed on a first wire bonding system; (b) determining a second wire payout length related to the predetermined wire looping motions used in the formation of a second of the wire loop; and (c) adjusting at least one wire bonding process variable, and repeating step (b) with the at least one adjusted wire bonding process variable such that the second wire payout length determined in the repeated step (b) is closer to the first wire payout length than the second wire payout length determined in the initial step (b).