Semiconductor Bonding Machine Non-Contact Transfer Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermocompression bonding processes in semiconductor packaging are slow and inefficient, particularly due to issues with Non Conductive Film (NCF) becoming tacky at low temperatures, leading to unreliable handover of semiconductor elements during transfer and requiring extensive heating and cooling ramps.
Innovation Solution
The use of non-tacky transfer tools, such as Teflon or coated rubbers, and a gap-defining mechanism to transfer semiconductor elements across a predetermined gap without simultaneous contact with the bonding tool, allowing for higher temperature handovers and reduced mechanical adhesion, along with actively cooled transfer tools to manage thermal energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the film temperature is kept low to avoid tackiness during handover, then the film remains non-tacky and handover reliability is maintained, but extensive heating and cooling ramps are required which consume time and energy
Solution Approach 1:
The patent applies local quality by creating a temperature gradient across the semiconductor element - the back surface is heated to high temperature while the front surface with the NCF remains at lower temperature. This is achieved through selective heating zones or heated substrates that conduct heat locally, allowing the NCF to remain non-tacky during handover while the bonding surface reaches bonding temperature, thereby eliminating the need for extensive cooling ramps.
Solution Approach 2:
The heating process is segmented into distinct zones - a bonding zone that heats the substrate to high temperature and a handover zone that maintains lower temperature at the NCF interface. This spatial segmentation of temperature control allows simultaneous high-temperature bonding preparation and low-temperature tack-free handover, reducing overall cycle time.
2Reliability
If the film temperature is kept low to avoid tackiness during handover, then the film remains non-tacky, but extensive energy is consumed for heating and cooling ramps
Solution Approach 1:
By maintaining low temperature only at the NCF interface while heating the bonding surface locally, the patent eliminates the need to cool the entire system after bonding preparation. This localized temperature control significantly reduces energy consumption compared to global heating and cooling cycles.
Solution Approach 2:
The substrate is pre-heated to bonding temperature through the substrate before handover occurs, so that when the element is transferred to the bonding tool, the bonding surface is already at the required temperature. This preliminary heating action eliminates the need for post-handover heating and reduces cooling requirements.
3Reliability
If conventional thermocompression bonding processes are used, then bonding can be achieved, but the processes are slow and productivity is low
Solution Approach 1:
The substrate is pre-heated to bonding temperature before the actual bonding operation through conductive heating from the substrate back surface. This preliminary heating eliminates the need for slow heating ramps during the bonding cycle itself, significantly reducing cycle time and increasing productivity while maintaining bonding quality.
Solution Approach 2:
The heating process continues during the handover operation rather than being interrupted. The substrate maintains bonding temperature throughout the transfer process, eliminating idle time between heating and bonding operations, thereby increasing overall process efficiency and units per hour.
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 enhances the productivity of bonding machines by enabling higher temperature handovers with reduced energy consumption and deformation of NCF, thereby increasing the units per hour (UPH) and improving the reliability of the bonding process.
Implementation Method 1
The transfer tool includes a cooling system for cooling a contact surface of the transfer tool
Implementation Method 2
transferred across a predetermined gap to the bonding tool without the transfer tool and the bonding tool contacting the semiconductor element at the same time
Data Source
AI summary
A method of operating a bonding machine is provided. The method includes the steps of: (a) carrying a semiconductor element with a transfer tool; and (b) transferring the semiconductor element from the transfer tool to a bonding tool of the bonding machine without the transfer tool and the bonding tool contacting the semiconductor element at the same time.