Bond Head Thermal Expansion Compensation in Semiconductor Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bonding machines face challenges in maintaining accurate positioning of semiconductor elements due to thermal growth and contraction of the bond head assembly during the bonding process, leading to undesirable changes in the z-axis position and affecting the quality of solder bonds.
Innovation Solution
The method involves measuring the z-axis height characteristic during a model bonding process to determine a z-axis adjustment profile, which is used to adjust the bond head assembly's position in real-time, compensating for thermal expansion and contraction, thereby maintaining accurate height control and ensuring consistent solder bond quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heat is applied to the bond head assembly during bonding process, then bonding capability is improved, but thermal expansion causes z-axis position drift
Solution Approach 1:
The system performs a model bonding process before actual production to pre-determine the thermal growth characteristics of the bond head assembly. This preliminary characterization allows the system to establish compensation profiles in advance, so that when actual bonding occurs, the pre-calculated compensation values can be applied to maintain positioning accuracy despite thermal expansion.
Solution Approach 2:
The system continuously monitors z-axis position during bonding operations and applies real-time compensation based on the measured thermal growth characteristics. The feedback loop compares the actual position with the expected position (accounting for thermal expansion) and adjusts the bonding parameters accordingly to maintain manufacturing precision.
2Reliability
If the bond head assembly is heated during bonding, then solder bonding capability is improved, but the z-axis height measurement drifts due to thermal expansion
Solution Approach 1:
The system performs a model bonding process to pre-determine the thermal growth characteristics of the bond head assembly before actual production. This preliminary characterization allows the system to establish compensation profiles that account for thermal expansion, ensuring that height measurements remain accurate even when the bond head is heated during solder bonding operations.
Solution Approach 2:
The system changes the operational parameters by applying dynamic compensation values to the z-axis position based on the measured thermal growth characteristics. This parameter adjustment allows the system to maintain measurement precision despite the thermal expansion that occurs during heated bonding processes.
3Manufacturing precision
If real-time z-axis position compensation is implemented, then positioning accuracy is improved, but system complexity increases
Solution Approach 1:
The system performs a model bonding process to pre-determine thermal growth characteristics and establish compensation profiles before actual production. This preliminary action simplifies the real-time control by using pre-calculated compensation values rather than requiring complex real-time thermal modeling and calculation during high-speed bonding operations.
Solution Approach 2:
The system creates a simplified representation of the thermal growth behavior through the model bonding process, storing the compensation characteristics in lookup tables or profiles. This copied information can be quickly referenced during actual bonding without requiring complex real-time calculations, thus reducing control system complexity while maintaining positioning accuracy.
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 ensures precise positioning of the bond head assembly, maintaining the desired gap tolerance between semiconductor elements and substrates, resulting in high-quality solder bonds with improved reliability and consistency.
Implementation Method 1
Through the cyclical application of heat (e.g., through the heater in the bond head assembly), and through changes to the system based on time, expansion and retraction of elements of the bond head assembly may lead to an undesirable result.
Data Source
AI summary
A method of operating a bonding machine for bonding semiconductor elements is provided. The method includes the steps of: (a) measuring a time based z-axis height measurement characteristic of a bond head assembly during a model bonding process; (b) determining a z-axis adjustment profile for a subsequent bonding process based on the measured time based z-axis height measurement characteristic; and (c) adjusting a z-axis position of the bond head assembly with a z-axis motion system during the subsequent bonding process using the z-axis adjustment profile.